Money For Nothing And Your Yeast For Free

Brew better beer and save money in the process by washing your own yeast for reuse in future brews. Always have a fresh supply of healthy yeast on hand and brew like the pros brew, it's a lot easier to do than you might think. The most obvious benefits of washing your own yeast are always having a good supply of viable cells on hand when needed, brewing way better tasting beer as the new yeast generations adapt to your brewing environment and saving lots of money on future yeast purchases.

On bottling day after having bottled up the very first batch of my 1960's Era Ballantine IPA recipe, one that I had spent a very considerable amount of time researching before creating the recipe and brewing it, I decided to wash the East Coast Yeast ECY10 - Old Newark Ale™ yeast that was at the bottom of the fermentor and store it for later use when making a starter to pitch into my next batch of beer. After cold crashing the washed yeast for five days at 36F the yeast cells flocculated out of suspension and formed a thick cream colored yeast cake on the bottom of the jar. Using a turkey baster I carefully sucked the top layer of the yeast cake into the baster and squirted the yeast into a dozen liquid yeast vials for storage.

East Coast Yeast ECY10 - Old Newark Ale™

 The yeast in the vials when stored at 36F in a refrigerator can retain a reasonable number of viable cells for up to 6 months or more. The yeast in the vials eventually settles out of solution and forms a thick yeast cake at the bottom of the vial, about half the amount per vial when compared to the nearly full vials White Labs ships its yeast in. When I'm ready to use my previously washed yeast I make a starter by adding two vials of  yeast to a 2000ml Erlenmeyer flask filled with a 1.040 wort and set it spinning on a stirplate. As a side note I found it to be easier to use StarSan for sanitizing the vials, caps, jars, turkey baster and anything else that may come into contact with the yeast. StarSan is fast acting and just as effective as boiling everything and it saves a lot of time besides eliminating the need to handle boiling hot jars, lids and water.
 

One Gallon Of Washed Yeast Slurry

I fill a tall one gallon jar up with filtered water, boil that water in a small pot it for 15 minutes then let it cool down to 72F leaving the lid on the pot. Once the water's cooled to the same temperature as the yeast cake left in the fermentor I just pour in all the water and stir it all up together by gently mixing the yeast and water with a sanitized spoon. With water and yeast all stirred up into a nice slurry together I open the spigot on the fermentor and fill the sanitized gallon jar up with the washed yeast slurry. The yeast in the slurry will slowly start to separate from the beer as the yeast cells began to settle out of solution and form a thick layer of yeast cake at the bottom of the jar.

Vials Of ECY-10 Estimated 50 Billion Cell Count Each

After tightening the lid on the jar again and spraying it with StarSan I put a sheet of plastic wrap over the top of the jar, held in place with an elastic band,  then put the jar in the refrigerator. About 5-7 days later the same milky yeast slurry becomes sparkling clear as the yeast settles out of solution and compacts at the bottom of the jar. Using a sanitized turkey baster I carefully suck up the thick yeast paste on the bottom of the jar, this is where all the healthy new yeast cells are, and fill up the vials for storage.

Excess Yeast Slurry At Left Washed Yeast Vials At Right

 I always make starters when using my washed yeast, even if the washed yeast has been stored in the refrigerator for only a week or two. Starters are all about having healthy yeast cells and then increasing the cell count. As for determining actual cell count in each vial I use an easy and reliable method, I fill up a White Labs vial with washed yeast, let it settle out and compact on the bottom of the vial and then eyeball it against what ship in a new vial of yeast. I know that White Labs ships 80-100 billion cells in their yeast vials and they contain about twice the volume of yeast stored in my vials of washed yeast that seem to contain about 50 billions cells each.

1.040 Starter Wort With Yeast Nutrient And Crumbled Hops

 I start out with 2000ml of filtered water and add to it 1.5 cups of extra light DME and mix it together thoroughly in a small pot before bringing it all to a boil for 10 minutes. I put in a small amount of pellet hop as a preservative and a pinch of yeast nutrient to help coax the yeast into producing plenty of very healthy new cells in the starter. At this point making a yeast starter is really just like brewing up a low alcohol mini batch of beer, but instead of using it to make beer it'll be used solely for the purpose of making more healthy yeast.

Cold Crashing The Boiling Wort To Pitching Temperature

Once the starter wort is the same temperature as the liquid yeast I pour two of my stored vials of yeast, each estimated to hold 50 billion healthy yeast cell,  into the Erlenmeyer flask through a stainless steel funnel. Next I pour the cooled wort through the funnel and fill the flask up to the 2000ml line and give the yeast and wort mixture a small burst of pure oxygen to get them off to a running start. The stirbar gets dropped into the flask and I spray a square piece of aluminum foil with StarSan and fold it over the top of the flask to cover the opening. Two things should be noted about covering the flask top with aluminum foil, you only want to fold it loosely over the top to allow the Co2 produced by the yeast to escape the flask and be replaced with room air. Also the bacteria and other things that are known to infect beer can not crawl, so there is a zero chance  of anything bad getting inside the flask while it's opening is covered with the foil.

Phases Of A Typical Starter Taken 12 Hours Apart

Even when boiling extra light DME to make my wort it has a darker color when it's first poured into the Erlenmeyer flask as shown in the first image on left in the picture above. But that soon will change as the sugars in the wort are consumed and processed by a rapidly growing population of yeast cells. When all the right starter conditions have been met a more than doubling the original yeast cell count can be excepted, I'd like to think my final cell counts are coming out consistently to close to 240 billions cells per starter.

When making a yeast starter it's critical to formulate, as precisely as possible, the recommended inoculation rate of viable yeast cells for 2000ml of 1.040 starter wort. I use a very simple formula where my inoculation rate starts out as close to 100 billions cells as possible and I expect that number to increase to between 220-240 billion cells once the starters finished.

Pitching Rate Calculator

 I like to pitch what some may feel is a large starter, I base my pitching rate calculations on two things the alcohol content expected once fermentation has completed and the type of yeast being used as being either an Ale or a Lager strain. My current dark ale recipe was calculated to come in 8.4% ABV and for that fermentation to go smoothly knew I needed a pitching rate of nearly 300 billion healthy viable yeast cells. I've spent the past several years fermenting my ales and lagers at their lower temperature ranges and expecting aggressive fermentations with minimal lag times. I'm on a mission to get the cleanest tastes from my malts and other additions and not have them muddied up by a bunch of yeast induced esters, unless you're into farmhouse ales and sour beers you'll probably agree with me on this one important piece of information.

Cold Crashing Starters At Day 1, Day 2 And Day 3

At the start of the new year the first recipe I brewed was my Hammerfest Marzen Lager, over the years I've brewed this style using several different ingredients and approaches to brewing, fermenting and lagering in order to find one that produced the very best tasting beer. I can't do all the brewing calculations needed on a typical brewday, or brew a recipe on paper, I rely on my brewing calculators to do most of the work for me. A medium to low gravity 5.5% ABV lager beer fermented at 52F needed a pitching rate of nearly 400 billion viable cells to ferment a five gallon batch, so I had to make two starters in parallel that week.

White Labs WLP820 - Oktoberfest/Märzen Lager Yeast™

At the end of the day all I wanted was the yeast I had no intentions of pitching a gallon of nasty tasting starter wort into my five gallon batch of beer and ruin the taste of it. Placing the starter flasks in the refrigerator at 36F for 3 days did the trick. The starters were very cloudy after coming off the stirplates but began to clear by the end of the first day and had completely cleared by the third day in the refrigerator. Pouring off, or decanting, the starter wort from the flasks and leaving just enough to swirl the yeast cake into solution from the bottom of the flasks and the yeast was now ready to pitch.

Oxygenated Wort Prior To Pitching Yeast Is The Best

Yeast nutrient has long since been included in all of my beer recipes just the way using pure oxygen and a micron diffuser to oxygenate the wort has replaced all other forms of aeration prior to pitching the yeast. During the early or aerobic phase of fermentation the yeast cells begin taking in nutrients, building strength, storing up energy reserves and reproducing at a very aggressive rate. They continue converting oxygen and nutrients into energy and reproduction until nearly all the oxygen in the fermenting beer has been depleted.

Now during the primary fermentation, or anaerobic, phase the yeast rewire their pathways and start converting the sugars in the fermenting beer into Co2 and alcohol. By reducing the length of time in the aerobic phase the excessive build up of flavor precursors are also reduced and the primary fermentation that follows can easily convert those precursors before going dormant at the end of the fermentation.

The Four Phases Of Fermentation

Phase 1 begins as soon as you pitch your yeast and is referred to as the lag phase, which we brewers want to keep as short as possible. The yeast are using up the sugars and oxygen in the wort to load up their food reserves, they won't ferment anything until they've been well fed. Stressing the yeast out with too high temperatures or too low numbers of viable cells will prolong the lag phase and the fermentation will take longer to complete while increasing the amounts and types of off flavors like diacetyl that may or may not ever condition out.

Phase 2 starts as soon as the lag phase ends because now the yeast have enough energy stored up to start multiplying, this is referred to as the growth phase. This is where you begin to see a bit of foam floating at the surface the wort from the production of Co2 and the pH and oxygen levels of the wort will start dropping. If you've pitched enough healthy yeast at the right temperatures into well aerated wort the lag time should have been 6-12 hours and the yeast are now full of energy and off to a very healthy start.

Phase 3 begins as soon as the growth phase is done and is triggered by a lack of oxygen in the wort, this is known as the fermentation phase. This is the phase where the production of Co2, alcohol and your beer's flavor is at it's peak and the wort temperature rises 3-5F higher than the ambient air outside the fermentor. The yeast will stay in suspension, so they come in contact with as many sugars as possible, over the next 3-7 days before they run out of sugars to eat and flocculate out to the bottom of the fermentor. Higher temperatures during this phase will produce more esters or fruity flavors and aromas, like the banana flavors in a hefeweizen. It's interesting to note that another cause of ester production is wort that hasn't been aerated enough.

Phase 4 is the final phase of the fermentation process and it's referred to as the sedimentation phase where the yeast begin consuming and converting any remaining flavor precursors in the wort like diacetyl that will produce off flavors in your beer. During this phase the yeast cells are preparing themselves to go dormant and storing up energy reserves for their deep sleep, even though this is where most of us flush them down the drain. I'd like to point out that the amount of cleanup work left for the yeast to do is dependent on how well we treated, or mistreated, our yeast during the first 3 fermentation phases.

During the sedimentation phase I raise the temperature of my fermentors 3-5F and hold it there for at least 3 days before bottling or kegging my beer. I do this because the yeast will only convert the flavor precursors they created earlier if the beer is warmer than it was when they were created. There is a limit to this rule though since the yeast can only do so much cleanup before they go dormant. Once the yeast go dormant any remaining flavor precursors will be left in your beer to produce off flavors.

Screwy's Golden Age IPA

For you history buffs out there Ballantine IPA was once the largest most popular selling beer in America beating out another upstart of that time named Budweiser. At the height of their fame Ballantine owned their own grain warehouse, malting house and even had their own hop oil extraction process which they used in abundance in their beers of the day. The original 1960's era Ballantine IPA was recorded as having been a 7.5% ABV 60 IBU aged in wood for up to a year before bottling. I've researched the historical records for this original recipe and managed to create an all grain version I call 'Screwy's Golden Age IPA' fermented with East Coast Yeast ECY10 - Old Newark Ale™ yeast, the original strain of yeast used back then in the Newark NJ brewery.

Go All Out With Your Next Fermentation

I have to tell you I was a bit skeptical myself about using pure oxygen when preparing my wort for fermentation, but after having done two batches I'm already convinced it is well worth it. Let me explain, the beers I'm drinking now are way, way better tasting than anything I've brewed prior to oxygenating my wort instead of just aerating it. Using oxygen is also saving me valuable time on brewday, a one minute burst of pure oxygen is all that's needed, while eliminating any risk of contamination when aerating with air for extended periods.

420 Special Wheat And East Coast Yeast ECY12 - Old Newark Beer™

Truth be told I started adding yeast nutrients to the wort boil at the same time I began using pure oxygen to prepare my wort for pitching yeast. I now add both a capsule of Servomyces nutritional yeast supplement and half a teaspoon of yeast nutrient to the end of all my wort boils to provide the yeast with a rich blend of sugars and minerals during fermentation. Maybe it's the combination of pitching, at the time of this post a fourth generation two liter starter of ECY-12 yeast at high krausen, adding yeast nutrients to the boil and then oxygenating the wort prior to pitching the yeast but there is a very noticeable difference in the quality of the finished beer now.

Additional information: Yeast Nutrients Make Better Beer by Christopher White, Ph.D

Attenuation Chart (Courtesy of White Labs)

For one thing the pitched yeast lag time has increased by about 20-30%, I don't notice much activity in the airlock for at least 18-24 hours but the beer's final gravity is finishing several points lower than it used to in prior batches fermented without oxygenation or nutritional supplements. Using aeration you can get at the very most 8ppm of oxygen into your wort by vigorously shaking your fermentor for a minute or using an aquarium pump, HEPA filter and air stone for at least five minutes.

Rapidly Cool Full Wort Boils To Pitching Temperature

Either of these methods creates a lot of wort foaming that can lead to issues with overflowing fermentors, head retention and lacing in your finished beer as well as increasing the risk of contamination. I use a 2 micron stainless steel diffuser and run enough pure oxygen through it to form a stream of very fine bubbles and I let it run for a full minute before pitching my yeast starter. At this rate flow rate, using the chart above as a guide, I can estimate that I am putting about 9ppm of dissolved oxygen into my wort which is the sweet spot for the beers I've been brewing.

Higher Yeast Production With Nutrients

The most notable change is in the taste and flavor of the beer now each sip tastes very clean, I mean there are no distracting off flavors so every ingredient you put in the kettle comes through clearly in the finished beer. I've been focusing mostly on my 420 Special Wheat and Screwer In The Rye recipes the past several months and since improving my yeast preparation as I have described earlier they have both developed an unmistakable clean flavor and aroma that leaves a really nice taste in your mouth after each glass.

Control Fermentation Temperature For Better Beer

Since East Coast Yeast ECY12 - Old Newark Beer™ yeast has an optimum temperature range of between between 53-68° F which is much lower than most Ale (Saccharomyces cerevisiae) yeasts but it is not a true Lager (Saccharomyces uvarum) yeast. I always pitch a healthy two liter starter into my five gallon batch and keep the temperature down around 55-57° F during the lag phase and then allow it to rise to 59° F for the primary fermentation phase. Once the primary fermentation has completed I add my dry hops and let the temperature slowly rise to 68-72° F over the next week. I then move the fermentor to my refrigerator to cold crash at 36-38° F for about four days before kegging or bottling it up.

Collecting Washed Yeast After Kegging The Beer

Once the beer has been bottled or kegged it's the best time to collect and wash the yeast from that fermentation to add to your yeast library for later reuse. I fill up a large pickle jar with filtered water, boil it for 15 minutes to remove as much oxygen from the water as possible, then cool it down to the same temperature of the yeast cake in the fermentor. Then I sanitize the jar and pour the cooled water into it, dump the water in the fermentor and then swirl the solution around for a minute or two using a long handled Teflon spoon. After a few minutes I open the valve on the fermentor and pour the washed yeast into the large jar until its full, a little while later I use it to fill up the pint mason jars I use to store the yeast.


I made the decision to just bite the bullet and go all out to treat my yeast the best I could. I wanted to find out for myself exactly how much of a real difference added nutrients and oxygen would make and I was pleasantly surprised. If you have been considering making the move to pure oxygen do it you won't be disappointed.

Oxynator Oxygen Gauge And 2 Micron Diffuser

I recently purchased an oxygen regulator and a stainless steel 2 micron diffusion stone from Rebel Brewer only to find out that the regulator and stone had different sized hose barbs. The regulator had a 1/8 inch hose barb and the stone had a 1/4 inch hose barb. Needless to say connecting the two with a piece of vinyl tubing and getting an air tight seal was no easy task.

Rebel Brewer Oxygen Regulator And Diffuser Stone Hookup

 After a lot of trial and error I was finally able to get it connected properly. I used a length of 3/16 inch vinyl tubing and soaked one end in near boiling water and stretched it until it slipped over the 1/4 inch hose barb on the stone. I then cut a one inch long piece of 3/16 inch tubing and slipped it over the 1/8 inch hose barb on the oxygen regulator. I soaked the other end of the tubing in the hot water and used a pair of needle nose pliers, slipped inside the tubing, to stretch it until it was large enough to fit over the tubing on the regulator.

Doubled Up 3/16 Inch Tubing And Hose Clamp On Regulator

 Although the folks at Rebel Brewer suggested that I do this, just as they'd advised other brewers who bought the same setup from them, you think they would have offered the stone and regulator pair with the same diameter hose barb.

Completed Air Tight Connections On Diffuser And Regulator

 I know from my fish keeping days that the tinier the air stone bubbles the more efficiently the oxygen is transferred and absorbed into liquids. In the case of an aquarium and aeration stones using room air you can double the surface area of the fish tank, allowing you to keep more or larger fish, but the bubbles have to be really small. For getting oxygen back into wort the same principal is also true and in time I'll get the flow rate and duration just right.

Regulator Adjusted To Provide The Finest Bubbles

 Yesterday I used the new oxygen setup for aerating my wort once I'd pitched my pitching. I soaked the diffuser stone and tubing in StarSan for 10 minutes, placed the stone at the bottom of the fermentor filled with five gallons of wort opened the valve and let the oxygen flow for 30 seconds. The next morning the airlock was busy pumping out Co2 as I've come to expect, in a few weeks I'll know if using the new oxygen setup makes a difference but so far the lag times were very short and the primary fermentation very aggressive.

Left Handed Threads Fit Oxygen Tanks From Home Depot

 Using the new oxygen setup shortened up my the brewing day, by eliminating the manual aeration I used to do using a long handled spoon, by nearly 10 minutes. When brewing this batch of beer I also added White Labs Servomyces and White Labs Yeast Nutrient to the end of the boil and also added some expired dried yeast to the boil of the two liter starter when I made it. I've used good sanitation when washing and storing the yeast and maintained good temperature control when pitching the yeast and fermenting the beer and I can't wait to taste the results for myself.

Identifying Washed Yeast - What To Look For

I've learned a lot about yeast this year, a lot more than I knew even a year ago. Since I started washing and reusing the yeast I use to ferment my beers with I've discovered how to identify some of the different strains too. Yesterday after bottling a batch of Mr. Beer/Coopers Bavarian Weissbier, washing the yeast and putting the mason jars in the mini-fridge where I store my yeast strains I saw 6 jars of yeast that I had forgotten to label.

Screwy's 420 Special American Wheat

You've been there too I'm sure where you put something off thinking I'll do it later while I still remember and then days go by and surprise you have no clue which was which. Well fortunately after being in the refrigerator for at least two weeks the yeast had stratified into very distinct layers and the order that the layers were stacked made it fairly easy to tell the strains apart.

Left To Right ECY-12, WLP-001 And WLP-400

The two unlabeled strains were White Labs WLP001 - California Ale Yeast™ and East Coast Yeast ECY12 - Old Newark Beer™ with the WLP-001 being a top fermenting 68-73F ale yeast and the ECY-12 being a bottom fermenting 53-68F lager yeast. As you can see the fermentation requirements and characteristics of these two strains are very different and mixing up the temperature ranges would really produce some uncharacteristic flavors for either strain.

ECY-12 With Trub Layer Under Yeast

As it turned out the jars containing the WLP-001 yeast stratified with a thin layer of trub lyiing on top of the creamy white layer of ale yeast. With the ECY-12 the trub layer was clearly visible underneath the the creamy white layer of lager yeast. Luckily I had taken the time to label several other jars of WLP-001 and ECY-12 from prior batches so I had them to use as a comparison. The end result enabled me to label three jars as WLP-001 and the remaining jars as ECY-12, now I'm feeling a lot more organized and secure in the fact that my next fermentation will be done using the right yeast.

WLP-001 With Trub Layer On Top Of Yeast

As of this posting the WLP400 - Belgian Wit Ale Yeast™ has still not completely stratified the less flocculant cells are still in suspension after a week in the refrigerator. Already clearly visible under the yeast layer is the trub layer which consists mainly of proteins and dead yeast cells. In all instances the creamy white layer is the yeast layer and no matter how you proceed from here in using the washed yeast it is this layer that really matters.

WLP-400 With Trub Layer Under Yeast

If you decide to decant the washed yeast slurry too soon before the layers have completely finished stratifying you will undoubtedly pour off some of the least flocculant cells which are key to getting the maximum attenuation during fermentation. I have a dedicated mini refrigerator that I keep all my yeast jars in and it doesn't get opened too often which is a good thing. I've used my washed yeast to make a starter after storing it there for six months and the beer it made was great.

Money For Nothin' And Your Yeast For Free!

Making A Starter From Harvested Yeast

Last month I brewed a version of my of my Screwer In The Rye Lager pitching two bottles of East Coast Yeast ECY12 - Old Newark Beer™ yeast into a five gallon batch. The recipe is all grain with a 1.060 original gravity and at 59F it fermented down to a 1.014 final gravity in just under three weeks time. The fermentation took off vigorously with a short lag time and the beer was a huge hit with those lager lovers lucky enough to sample it before it ran out.

 Early on bottling day I filled a 16 quart pot with about a gallon of filtered water, put the lid on it and let it boil for about 15 minutes to sterilize it. I removed the pot from the heat to cool off leaving the lid on, this water would be used to rinse the yeast out of the fermentor. Once I sanitized my bottles and bottling bucket I put the pot in an ice water bath to get the sterilized water equal to the beer temperature. I transferred the beer from the fermentor to the bottling bucket leaving just the trub in the fermentor.

Then I sanitized a long handled plastic spoon, glass half gallon pickle jar, four pint mason jars and the lids to get them ready for the next step. I poured a half gallon of the sterilized water directly on top of the trub in the fermentor and used the spoon to gently mix the water and trub together to get the yeast into solution. After a minute of gentle stirring I carefully poured the mixture in the fermentor into the pickle jar filling it up to the very top and screwed on the top. I set the pickle jar aside and went back to bottling up my beer.

Stratified Layers In ECY-12 And WLP007 Yeast

 The healthy yeast layer we're really interest in storing has a nice light creamy color and it is located just above the heavier trub/cold break layer at the bottom of the containers. The ECY-12 lager yeast on the left is a medium flocculent yeast so more cells will tend to stay in suspension longer than the highly flocculent WLP007 ale yeast on the right. When washing any strain of yeast it's important to harvest a good mixture of both the more flocculent and less flocculent cells in each type of yeast to assure your future fermentations will continue to attenuate as fully as the original strain. 

Mason Jars Filled With Washed ECY-12

Buy the time I was done bottling my beer the slurry in the pickle jar had started separating into separate layers, with the heavier hop particles and dead yeast cells settling out first at the bottom of the jar. The very top of the slurry had a thin layer of something and in between the two was the larger layer of yeast. I laid the four mason jars out in a line and filled each one up half way then went back to the first jar and topped them all off in the same order. What was left in the pickle jar was mostly all gritty looking trub that I washed down the sink after screwing the lids on the mason jars, labeling and putting them in the refrigerator.

Freshly Rinsed And Stored Yeast

 Fast forward to this past Friday morning when I started off my day by brewing up a 1.040 batch of wort to use in my starter and taking a mason jar of stored yeast out of the refrigerator to warm up. A half cup of light DME mixed in with 1200 ml of filtered water some old dry yeast and boiled for 15 minutes was all it took to get going. Once the wort and yeast were at the same temperature I sanitized my Erlenmeyer flask, funnel, stir bar and decanted off most of the water from the mason. I shook the yeast and water in the jar to break up the flocs, get all the yeast into solution and then poured it into the flask topping the flask off with the starter wort. I dropped in the stir bar, sprayed the top of the flask loosely covered the opening with a piece of sanitized tin foil and set the flask on the stirplate.

ECY-12 Yeast Starter Before Pitching

Several hours later a nice layer of krausen had begun to form on top of the starter which peaked around eight hours later. I left the starter spinning on the stir plate until I was ready to pitch it into my wort the next day. I began the making the starter on Friday morning and pitched into a batch of wort around 3:00 pm the next day as soon as the wort cooled to the same 60F temperature as the yeast. This time I remembered to hold the stir bar in place with a magnet so it didn't end up inside the fermentor for a few weeks. The wort from the flask smelled good, there were no off odors when I pitched it and the fermentation started quickly. I checked the air lock this morning and there was already activity from the Co2 being created from inside the fermentor.

Aerated Rye Wort With ECY-12 Starter

The fermentor is now safely tucked away inside my fermentation chamber where I'll keep a close eye on maintaining a 59F temperature throughout the fermentation. It'll be a few weeks before I get to taste the fermented rye beer and compare it to the first batch I brewed last month but judging from the 1.060 original gravity reading, color and the taste of the wort before pitching the yeast this batch is definitely off to a great start.

What Every Brewer Should Know About Yeast

As a new brewer it took me quite a while before I was able to understand what was going on inside the LBKs during 'the fermentation'. I see posts here all the time from new and conditioned brewers alike about off flavors in their beer and how or why they have them. So this morning I decided to sit down with my morning coffee, since I couldn't sleep anyway, and try to set the record straight and try to explain the 4 things every brewer should know about yeast.

Here's how I view the relationship between yeast, off flavors and fermentation temperatures throughout the typical beer fermentation. While I'm writing this with brewing an Ale in mind the same principals apply equally to Lager fermentations too.

Phase 1 begins as soon as you pitch your yeast and is referred to as the lag phase, which we brewers want to keep as short as possible. The yeast are using up the sugars and oxygen in the wort to load up their food reserves, they won't ferment anything until they've been well fed. Stressing the yeast out with too high temperatures or too low numbers of viable cells will prolong the lag phase and the fermentation will take longer to complete while increasing the amounts and types of off flavors like diacetyl that may or may not ever condition out.

Phase 2 starts as soon as the lag phase ends because now the yeast have enough energy stored up to start multiplying, this is referred to as the growth phase. This is where you begin to see a bit of foam floating at the surface the wort from the production of Co2 and the pH and oxygen levels of the wort will start dropping. If you've pitched enough healthy yeast at the right temperatures into well aerated wort the lag time should have been 6-12 hours and the yeast are now full of energy and off to a very healthy start.

Phase 3 begins as soon as the growth phase is done and is triggered by a lack of oxygen in the wort, this is known as the fermentation phase. This is the phase where the production of Co2, alcohol and your beer's flavor is at it's peak and the wort temperature rises 3-5F higher than the ambient air outside the fermentor. The yeast will stay in suspension, so they come in contact with as many sugars as possible, over the next 3-7 days before they run out of sugars to eat and flocculate out to the bottom of the fermentor. Higher temperatures during this phase will produce more esters or fruity flavors and aromas, like the banana flavors in a hefeweizen. It's interesting to note that another cause of ester production is wort that hasn't been aerated enough.

Phase 4 is the final phase of the fermentation process and it's referred to as the sedimentation phase where the yeast begin consuming and converting any remaining flavor precursors in the wort like diacetyl that will produce off flavors in your beer. During this phase the yeast cells are preparing themselves to go dormant and storing up energy reserves for their deep sleep, even though this is where most of us flush them down the drain. I'd like to point out that the amount of cleanup work left for the yeast to do is dependent on how well we treated, or mistreated, our yeast during the first 3 fermentation phases.

During the sedimentation phase I raise the temperature of my fermentors 3-5F and hold it there for at least 3 days before bottling or kegging my beer. I do this because the yeast will only convert the flavor precursors it created earlier if it's warmer than it was when they created them. There is a limit to this rule though since the yeast can only do so much cleanup before they go dormant. Once the yeast go dormant any remaining flavor precursors will be left in your beer to produce off flavors.

The moral of this post is to always use fresh healthy yeast in sufficient quantity pitched into well aerated wort at the recommended temperature and you will produce some great tasting beer.

Yeast Harvesting, Ranching And Starters

I'm basing this latest yeast related post based on research and information found on the Mr. Beer Community Forum posted by experienced brewers and forum members like Dr. Dink, esheppy and others. Many thanks to those fellow brewers who have come before us and found time in their busy lives to test out new processes and then publish their research and experiences in hopes of helping others.  

 Any good brewing process has to produce consistently favorable results and this can only be achieved by putting a theory to the test and tweaking it along until it's perfected. As with all grain brewing I had read and researched yeast harvesting and ranching as much as possible before actually trying it out for myself. Once I had all the items required it really wasn't all that hard to do, it just meant incorporating a new process into my current list of brewing processes.

Since originally posting this article I've adopted an easier way of harvesting and washing my yeast. Now instead of boiling all the jars, lids and utensils I use StarSan to sanitize them instead. I switched to using StarSan over boiling for two reasons, one it was too risky handling all those boiling hot jars and to save time. Now I put about a half gallon of water in a pot and boil it with the lid on for 10-15 minutes before taking it off of the heat. Then I let it cool off while I go about bottling or kegging my beer as usual when the fermentor's empty I make sure the boiled water is room temperature before pouring it right on top of the yeast cake. The mason jars, lids and utensils are soaked and sprayed with StarSan before using them and the yeast stored this way works just as good as boiling but it's much easier.

For my complete details see Making A Starter From Harvested Yeast

 

Yeast Harvesting - Eric Shepard

You can harvest a fresh batch of yeast from a batch of beer that has completed fermentation or a batch that is still fermenting, I decided to use the yeast from 2 Stout batches I was going to keg. A day before kegging my Barley Stout and Chocolate Stout I placed 6 six ounce mason jars and 2 twelve ounce mason jars into a 12 quart brew kettle boiled for 20 minutes, covered it and let cool off. 

 Boil Jars, Lids And Tongs For 20 minutes

1. Put the mason jars, lids, caps and a pair of tongs into a kettle filled with enough water to cover them and boil them for 20 minutes to both sanitize and remove oxygen from the water.

2. I let the water cool down for about 30 minutes before I used the tongs to fill the jars with the sterilized water and screw the lids on tight. I then let them cool off for another couple of hours before putting them in the fridge until cool overnight.

Carefully Lift Jars And Lids From Boiled Water

3. I had racked my stouts to secondaries 7 days ago and put them in the fridge to cold crash before kegging them so the temperature of the beer and the sterilized water in the jars were the same.

Transferring Stout To A Sanitized Keg Purged With Co2

4. After transferring the stout to my corny keg as I normally would I then poured the sanitized water from the mason jars into the fermenter and shook it to mix the trub up with the water.Let the fermenter sit for 20 minutes some separation may be noticeable at this point.

Trub At Bottom Of Mr. Beer Fermenter

Trub Mixed With Sterilized Water To Suspend Yeast

5. Pour the yeast/water mixture into the larger jars trying not to include any trub that separated out to the bottom of the fermenter.

After 20 Minutes Trub Settles To The Bottom

6. We don't want the trub we only want to harvest the suspended yeast so let the larger jars sit for 20 minutes again some separation may be noticeable at this point.

7. This time pour the yeast/water mixture into the smaller jars once again trying not to include any trub that separated out to the bottom of the larger jar.

Suspended Yeast In Smaller Jars And Trub In Larger Jar

8. Store the smaller jars of yeast in the refrigerator until needed for your next brewday then use them to create a yeast starter. You can make the starter by boiling a 1/2 cup of light DME in 2 cups of water for 10 minutes leaving the lid on and allow it to cool to 70F, this will create a starter with an original gravity of about 1.040. Pour the starter and a jar of yeast into a flask and add it to your wort when it's at high krausen which usually takes between 24-36 hours. See Screwy's DIY Stirplate

Harvested Windsor Yeast Stored In Refrigerator

Yeast Ranching - Dr Dink

You can ranch a fresh batch of liquid yeast by activating the smack pack as you normally do and letting it swell up according to the direction, usually between 3 to 24 hours. Next prepare the 1.040 OG starter wort by mixing 1/2 cup of light DME with 2 cups of water and and boiling it for 10 minutes. You can optionally add 1/4 teaspoon of yeast nutrient for a Mr. Beer sized batch to the wort before boiling it.

1. Smack the liquid yeast pack and allow it to swell as stated in the directions. (3-24 hours).

2. Boil 1/2 cup of light DME in 2 cups of water for 10 minutes leaving the lid on and allow it to cool to 70F.

3. Sanitize the stirplate flask and stir bar then pour in the cool wort and liquid yeast and cover with sanitized tin foil.

4. Place stirplate flask and stir bar on the stir plate and allow to spin for 48 hours maintaining 70F.

5. Sanitize 6 small mason jars and caps then swirl the starter wort to re-suspend the yeast and pour an equal amount into each of the 6 mason jars and then cap them.

6. Store the jars in the back of the refrigerator until needed then create another starter (see step 2) and add this new starter to your brew when it's at high krausen (about 24 hours).

When only one jar of the ranched yeast is left we can then use it to make a new starter that will make another 6 jars of ranched yeast. Label these as 2nd generation yeast, it is possible to repeat this process to produce 5 or 6 generations from the initial liquid yeast smack pack.

Screwy's Do It Yourself Stir Plate

 I've been thinking about how important yeast is to my brewing process and how much I've spent on buying yeast over the past year or so. Yeast can account for as much as 25-30% of the total cost of ingredients that go into a beer recipe and after brewing 45 batches of beer that adds up to a lot of money. I've been reading more and more lately about brewers who have published interesting ways of reducing the amount of money they spend on buying yeast for their recipes.

 Watch Stirplate In Action

  One of the ways to stretch my liquid yeast dollars is to create a 'starter' to ensure that the yeast I plan to use is viable and to increase the number of yeast cells before pitching them into my wort. Some brewers buy a liquid yeast strain for a recipe and use 25% of it to make a starter, then save the additional yeast grown from the starter in jars for use in their next recipes.

  One of the things I find my self doing when all my fermenters are full of fermenting beer is building some clever new beer device to use and eventually work it into my brewing process. This month I found myself thinking about stirplates, either buying one or building one from scratch. I came home from Radio Shack with a plastic project box, 4 small rare earth magnets and a 12 volt dc cooling fan and set out building my very own DIY stirplate.

 Stirbar Components Plastic Shrink Wrap And Rare Earth Magnets

 To make my own waterproof stirbar I first cut a 1 inch long piece of plastic heat shrink tubing and stuffed 4 small rare earth magnets inside until they were in the center of the tube. I then used a hot glue gun to seal both ends of the heat shrink tubing with glue, this will keep the magnets from moving or rusting while helping the stirbar to spin smoothly.

Heat Shrink Tubing With Magnets Inside

  The tubing is pretty small so it doesn't require much glue to seal up the ends once the magnets are centered inside the tubing.

Fill Ends Of Tubing With Hot Glue

 Mounting the fan to the cover of the project box was also done using hot glue. The fan produces almost no torque so it doesn't take much to secure the block of wood to the plastic box cover or the fan to the block of wood. The block of wood is a 3/4 x 1 x 3 inch drop off left over from my fermentation chamber project and when glued to the box cover it provide just the right amount of space needed between the magnets and the top of the case.

3/4 Inch Wood Spacer Positions Magnets To Top Of Box

 * Note: The white splatter on the inside of the fan housing was caused by turning the fan on when the superglue used to fasten the magnets to the fan was still wet.

 The large rare earth magnets I salvaged out of an old 40GB. hard drive I had lying around my workshop. These magnets are very powerful and they required a bit of persuasion to get them out of the case where they were located.

Two Arc Shaped Rare Earth Magnets Taken From Drive Head

 The type of hard drive I had used arc shaped magnets which were positioned underneath the drive head, the movable pointer shown in the upper left hand corner of the hard drive pictured above. After removing them from the hard drive I used super glue to secure them to one side of the 12 volt dc fan.

Radio Shack Parts List:
273-243 - 12 VDC Cooling Fan - 3 Inch
270-1806 - Project Enclosure - 6 x 4 x 2 Inches
64-1895 - 3/16 Inch Rare Earth Magnets - (2 Packages)

 I used the variable voltage power supply I have in my workshop to power the fan and adjust it's speed. The stirbar began spinning slowly when about 6 vdc was applied directly to the fan. I slowly increased the voltage to 12 vdc and the stirbar began spinning faster. You can hook up a 6, 9 or 12 volt dc power converter to power the fan directly if you have either of them lying around the house, or you can buy a variable voltage DC power converter.

  The glass vessel I used for the demo video was simply a 1 quart flower vase that I had on hand but the stirplate will also work with a standard Erlenmeyer Flask and an optional Teflon coated stirbar available at brewing supply houses such as William's Brewing.

Mr. Beer's Novacaine Recipe!!!

 I first brewed this recipe in early June 2010 and really didn't get around to drinking it for at least 4 months or so. Last night we drank 2 liters of Novacaine, as well as a bunch of other home brews, and everyone really liked this Barley Wine a lot. I remember opening the shipping box and pulling out what seemed like an endless amount of ingredients that would eventually go into making the Novacaine recipe.

 This recipe was then and still is the most expensive single batch brew I have ever made. The recipe included 5 cans of extract, liquid yeast and four packets of pellet hops and cost over $50.00 to buy not including shipping. I followed the recipe's instructions carefully and noted that there were a few things worth remembering for the next time I brewed it. 

I used qBrew's default 'American Barelywine' style guidelines to crunch this recipe's numbers. You can download the November 2010 qBrew database below and use it to upgrade your current ingredient database. This latest ingredient database includes more yeast, fruits, extracts and other helpful entries then ever before.

 Click to download Screwy's latest qBrew database   

Recipe:
Click to download this recipe file for qBrew 

Recipe: Size 2.13 gallons: Estimated IBU=48, SRU=36, OG=1.102, FG=1.026, ABV=9.9%

1 Can West Coast Pale Ale HME

1 Can St. Patrick's Irish Stout HME

1 Can Golden Wheat UME

2 Cans Pale Export UME

2 Packets Sterling Pellet Hops

2 Packets Northern Brewer Pellet Hops

1 Pouch Ale Liquid Yeast

2 Packets Dry Brewing Yeast (not used)

2 Muslin Hop Sacks

1 Packet One-Step™ Sanitizing Cleanser

Residual Co2 In Bottling Sample

 

 The first thing to remember is to use a pot larger than the standard 3 quart pot recommended in the instructions as this recipe calls for twice the volume of ingredients normally used in other recipes. This isn't an issue for me today as I had already switched to using a 6 quart stainless steel pot a few months ago. 

Bottom Filling Bottling Wand

 I had let the wort ferment for 21 days at a constant 70F temperature prior to bottling it in 1 liter PET bottles. Mostly all of the krausen was gone by then with only a few small islands of foam remaining at the top of the beer. There was a 3/8-1/2 inch layer of trub lying at the bottom of the 2.13 gallon fermenter but the fermented beer itself was very clear, thick and very tasty.

I Highly Recommend You Give Novacaine A Try