Saturday, May 6, 2017

How To Add A Whirpool Port To Your Kettle

The thought of drilling a hole in your favorite boil kettle can be intimidating to most any homebrewer. Unless of course they have had some previous metal working experience, or they can enlist the help of someone having the skills needed. The more adventurous do-it-yourself types, those who have access to a variable speed drill and the right drill bits, can easily handle the task, along with the help of some PAM cooking spray for lubrication.

Adding A Whirlpool Port To Your Kettle? No Problem
The installation of the whirlpool port shown in this article, including setup and cleanup time, took about two hours. Allow yourself additional time to obtain the items listed below. Having all of the required parts in hand from the start, will allow you to successfully complete the project from beginning to end in just a few easy steps. Everything needed to successfully install the bulkhead fitting and whirlpool port were very easy to find online and they can be delivered to your door in under 5 days.

Whats Needed:
Adjustable wrench and/or channel lock pliers 
Teflon tape
Center punch, or nail to mark the hole center
1/8" pilot hole drill bit
Milwaukee 3/16" to 7/8" Step Drill Bit #4
Stainless Steel Weldless Bulkhead 1/2" NPT
Anvil 1/2" NPT Swivel Dip Tube
Danco #12 Rubber O-Rings

Boiling wort is extremely hot and it has the potential to scald your skin in a matter of seconds. Coming into direct contact with boiling wort is also one of the most common causes of injury when brewing beer, something to keep in mind when working around it.

Pumping boiling wort from the kettle, through a counter-flow chiller and then returning the wort to the kettle, is a very effective way to sanitizing the counter-flow chiller. Returning the hot wort exiting the chiller to the kettle, by using a clamp on the kettle rim to hold the end of a silicone hose in place, is not a safe. Temporary clamps can slip and move, causing a loose hose end to unexpectedly spray hot wort on brewers and equipment.   

The safest way of returning hot wort to the kettle is through a permanently mounted whirlpool port. The use of a weldless whirlpool port ensures a solid physical connection between the kettle and the silicone tubing. Once a solid connection has been made between the two, the risks of hot wort unintentionally splashing outside of the kettle are greatly reduced. 

Weldless Bulkhead Fitting And 90 Degree Swivel Elbow
Every successful project begins with a well thought out plan. Knowing exactly where to locate the whirlpool port before drilling a hole in the kettle is a must. The orientation of the port, its distance from the bottom of the kettle and how far it will extend inside the kettle, are all critical factors to be considered. Once a suitable location for the port has been found, that works with the size and dimension of the parts ordered, you are ready to drill the hole.

Drilled Hole Shown With Metal Shavings And Food Grade Lubricant
Turning the kettle on its side, laying it on a floor or other stable surface, and preventing it from moving as much as possible will make marking and drilling the hole much easier. Using a center punch, or a nail, mark the side of the kettle with a small 'X' to indicate where the center of the hole will be. Next use a hammer and nail to strike a dimple in the side of the kettle at the center of the 'X'. The dimple in the metal will prevent the drill bit from wandering away from the hole center when drilling.

Spraying the hole center with PAM, or another food grade lubricant, will prevent the tip of the drill bit from burning up. Drilling holes in stainless steel requires a combination of steady pressure on the drill, slow bit rotation and plenty of lubrication to keep the tip of the drill bit cool and sharp. Center the tip of the 1/8 inch pilot bit into the dimple then trigger the drill on and off, using a slow drill speed while pressing firmly down on the drill.

Expanding The Pilot Hole Using A High Speed Step Drill Bit
Expanding the pilot hole to the finished hole size is easy when using a high speed step bit. Once again, to prevent the bit from dulling use plenty of lubricant, trigger the drill at a slow rotation speed and apply a firm downward pressure on the drill. Keep in mind that using a step bit with a maximum hole diameter, that matches the diameter of the hole needed for the whirlpool port, eliminates the possibility of making the hole too big. Extra care should be taken, to prevent drilling a hole larger than needed, when using a larger diameter step bit.   

Debur the inside surface of the hole by running the drill from inside the kettle, lubricating the bit and rotating the bit at a slow speed. Again if using a larger diameter step bit be careful not to press too hard and make the hole any larger than needed. A small, fine, half round stainless steel file can also be used to debur the inside of the hole. Paper towels can then be used to wipe up any lubricant and metal shavings before installing the whirlpool port.

Bulkhead Fitting Installed With Orange Washer And Grooved Nut
The threads of the bulkhead fitting point inside the kettle. The orange silicone washer, with matching grooved nut, hold the fitting in place and seal the hole to eliminate leaks. The orange washer is squeezed, between shoulder of the stainless steel coupling on the outside, the kettle wall, and the grooved nut tightened against it on the inside of the kettle. Care should be taken when tightening the nut. Over tightening the nut will push the soft silicone washer out from underneath the groove in the nut, and cause the bulkhead fitting to leak. 

Coupling Shoulder Tightened Against Outside Kettle Wall
After the mash has finished, and the grain basket has been removed from the kettle, the swivel dip tube is threaded onto the bulkhead fitting inside the kettle. The swivel dip tube is removed during the mash, to provide the space needed between the inside of the kettle and the outside of the perforated grain basket. If the swivel tube is left on the bulkhead fitting the grain basket would not fit inside the kettle.

Clearance Needed Between The Bulkhead Fitting And The Grain Basket
With the grain basket removed from the kettle the swivel dip tube can be threaded onto the bulkhead fitting and the wort brought to a boil. Pumping the boiling kettle wort through the counter-flow chiller and returning the wort to the kettle through the whirlpool port sanitizes the chiller while creating a strong whirlpool in the kettle. Increased hop utilization and greater hop isomerization is achieved when combining the whirlpool effect in the kettle with the use of a hop spider. 

Whirlpooling Hops To Increase Utilization And Isomerization
And there you have it. With a bit of advanced planning, the correct parts and the right tools for the job, you too can successfully install a whirlpool port in any kettle. The benefits of a having a whirlpool port in your kettle are many. Increased safety, improved hop utilization, clearer wort and the ability to do whirlpool hopstands, these are just a few of the benefits. Another benefit worth mentioning is in knowing that you were able to successfully do-it-yourself.  

Add A Whirlpool Port And Brew Better Beer!

Saturday, December 31, 2016

The Influence Of Grain DI pH On Mash pH

Distilled water, or highly purified water such as reverse osmosis water, are deficient in minerals such as calcium and magnesium. Because of the mineral deficiencies distilled water has zero alkalinity. It lacks the ability to resist pH change, it has zero buffering capacity. In the mash, grain introduces acid buffers that change the pH level of the mash. Lighter colored malt has a pH buffer value near pH 5.8 and darker colored malt has a pH buffer value near 4.7.

The optimal mash pH range required to ensure the most effective enzyme conversion in the mash, and the most efficient hop utilization in the boil, is in the pH range from 5.3 to 5.5. Brewing water used in the mash should be buffered in a way that will enable it to overcome the acidic buffer introduced by the grain. The acid and mineral levels of excellent brewing water provides enough alkalinity to hold the mash within the optimal pH range of 5.3 to 5.5.      

What Happens In The Mash?

What is DI pH and why is it important? The term DI pH is derived from the word distilled as in distilled water and pH as in pH value. You can determine the DI pH value of any grain by finely crushing 40 grams of grain, mixing it in with 100 milliliters of distilled water and then heating the resulting mash to 125°F for 20 minutes. A pH reading taken of the resulting wort when cooled to 77°F is the DI pH value of the grain. Various grain types, and sometimes the same grain type sourced from several maltsters, will have different DI pH values. Accurately calculating brewing water adjustments to optimize enzyme activity in the mash is largely dependent on knowing the correct DI pH value for each grain.

What happens in the mash tun during the mash? The mashing process can simply be stated as 'a mixture of grain and water, heated to a temperature of 149°F to 155°F in order to trigger the enzyme conversion of starch to sugar'. But there is more to it than that. The ratio of grain to water commonly referred to as the mash thickness, also affects the efficiency of conversion. It is a combination of mash temperature, mash thickness and pH that have an affect on mash efficiency.
  • To calculate mash efficiency take a hydrometer reading of the pre-boil wort volume, drop the decimal point then subtract 1000 from the reading, Next multiply that number by the pre-boil wort volume in gallons and then divide that number by the total pounds of grain in the recipe.
  • Example: With a pre-boil gravity of 1.048, dropping the decimal point and then subtracting 1000 equals 48. Multiplying 48 times 13 gallons of pre-boil volume equals 624. Dividing 624 by the 23 pounds of grain used in the recipe equals an extract efficiency of 27.1 
It is important to point out that the conversion of starch to sugar becomes much more efficient when the pH of the mash is between 5.1 and 5.3 at mash temperature. The same mash sample when cooled to 77°F measures between pH 5.3 to 5.5, something to keep in mind when referencing mash pH values.

The DI pH Values Differ Between Grain Types

How does the pH and the temperature of the mash influence my beer? Alpha and beta amylase enzymes in the mash convert starch into non-fermentable and fermentable sugars. The alpha amylase enzyme breaks down starches into glucose (dextrins), producing non-fermentable sugars that add fullness and body to beer. The optimal temperature range for the alpha amylase enzyme is between 145°F to 158°F and the optimal pH range is between 5.3 to 5.8.

The beta amylase enzyme breaks down starches and sugars into maltose, producing the highly fermentable sugars that are preferred by yeast the most. The optimal temperature range for the beta amylase enzyme is between 131°F to 149°F and the optimal pH range is between 5.0 to 5.6.

Test Mash Sample Used To Record Grain DI pH

A 149°F mash is will produce wort that makes a thinner, drier, higher alcohol beer. A 155°F mash produces a wort that makes a maltier, sweeter, fuller bodied beer. To a somewhat lesser extent a mash pH of 5.5, favoring the alpha amylase enzyme, will produce a less fermentable wort. Where a mash pH of 5.2, favoring the beta amylase enzyme, will increase the fermentability of the wort.

The available window of opportunity for a brewer to influence the fermentability of their wort is very narrow. Mashing at temperatures lower than 149°F, or higher than 155°F, will cause enzyme activity to slow down considerably resulting in a decrease in conversion efficiency.

Enzyme activity slows down when the mash pH falls below 5.1, or rises above 5.3 at mash temperature, resulting in a decrease in conversion efficiency. Mash temperatures or pH values that fall too far outside of their optimal range, change the shape of the enzymes causing them to become denatured, which reduces their ability to convert starch to sugar.     

Brewing Water Accuracy Is Dependent On The DI pH Value Of The Grist

Why is it important to know the DI pH values of the grains used in the mash? On average when grains are mashed using reverse osmosis or distilled water, the pH of the mash ends up in the 5.8 to 6.0 pH range. Lacking the buffering needed to resist pH change, distilled water will seek an equilibrium relative to the acid content of the grain, if left unchecked. It is important to point out that a mash pH of 5.8 to 6.0 is well outside of the optimal pH range for both the alpha and beta amylase enzymes.  

The acid content of different grains will vary from grain type to grain type and from maltster to maltster, even when they are producing the same type of grain. The acid content of a roasted malt can have a DI pH of 4.71 and the acid content of a pilsner malt can a much higher DI pH of 5.75. It is also true that 2-Row malt produced by Rahr can have a stated DI pH value of 5.56 while a 2-Row malt produced by Briess can have a DI pH value of 5.70. Some maltsters provide inaccurate information regarding the DI pH of their grain while other maltsters provide no information at all, which confuses the interpretation of DI pH values even further.

Testing Grains For Their DI pH Value Is Worth The Effort

Determining the DI pH of any grain can be accomplished by crushing 40 grams of malt and then stirring in 100 milliliters of distilled or reverse osmosis water to produce a 1.2 qt/lb ratio mash. Allow the mash to reach equilibrium by letting it settle for at least 20 minutes. During this time the pH of the mash will change. The darker the malt is the higher its acid content and the lower the pH value will be. Conversely the lighter the malt is the lower its acid content and the higher the pH value will be. Use a recently calibrated pH meter to take a reading of the test mash and then record the pH value as the DI pH value of the grain tested.

Just enter the DI pH values of grains that have been tested into ezBrewingWater-RO© and be confident that your brewing water profile has been accurately optimized for those grains when they are mashed.