Monday, January 21, 2013

Brewing The 2013 Hammerfest Marzen Lager

3B. Oktoberfest/Märzen: 

Rich German malt aroma of Vienna and or Munich malt a light to moderate toasted malt aroma is often present. Clean lager aroma with no fruity esters or diacetyl no hop aroma and Caramel aroma is inappropriate. Dark gold to deep orange-red color with bright clarity and solid off-white foam stand.

Grist varies, although German Vienna malt is often the backbone of the grain bill with some Munich malt, Pils malt and possibly some crystal malt. All malt should derive from the finest quality two-row barley. Noble hop varieties are most authentic. Somewhat alkaline water (up to 300 PPM), with significant carbonate content is welcome a decoction mash can help develop the rich malt profile.

OG: 1.050 – 1.057, IBUs: 20 – 28, FG: 1.012 – 1.016, SRM: 7 – 14, ABV: 4.8 – 5.7%

The preceding description was taken from the Beer Judge Certification Program description of the Oktoberfest/Marzen Lager style beer, the topic of this month's post and my first lager beer brewing project of 2013. The five gallon recipe I created calls for pitching 435 billion yeast cells of White Labs WLP820 - Oktoberfest/Märzen Lager Yeast™ at 56° F and fermenting at 50-54° F until a hydrometer sample reads 1.018, signalling the start of the diacetyl rest, then raising the temperature of the fermenting beer to 60° F over the course of three days.

Using a single infusion mash at 154° F for 60 minutes I included a small addition of Melanoidin malt to the grain bill to provide a big malty flavor and reddish color without having to do a complicated decoction mash schedule and extended boil on brewday. The other two grains used in the recipe are German Vienna malt, with roughly half as much German Munich malt, making up the backbone of the grist. The goal of this recipe is to produce as authentic tasting a Marzen Lager beer as I possibly can using my current brewing process. This beer should deliver all it's flavor and aroma from the recipe's malts, with no distractions caused by esters or hop additions to get in the way.

Oktoberfest/Marzen Lager
Size 5.50 gallons: Estimated IBU=27, SRM=11, OG=1.057, FG=1.014, ABV= 5.5%

For bittering I chose to use Czech Saaz hops and a smaller amount of Slovenia Styrian Gold in the kettle to offset the malt sweetness and compliment the malty biscuit aroma of the grains. I used my local tap water, which is not considered to be hard, filtered with a two stage G&E water filter before using it in the mash, I haven't had my tap water analyzed yet and I didn't add do anything else to modify the water profile to increase the hardness to 300 PPM. Well there we have it all the background information about the beer style the ingredients the brewing process and what to look for in the finished beer.

I picked up a really fresh vial of White Labs WLP820 - Oktoberfest/Märzen Lager Yeast™ at Princeton Homebrew and made a series of yeast starters over the course of a week to step up to the number of viable cells needed to ferment this beer. To prepare the starter wort I added 1 cup of extra light dme to 2 liters of filtered water then added a small pinch of yeast nutrient and boiled for 10 minutes. Once cooled and just prior to adding the vial of yeast I hit the starter wort with a burst of pure oxygen, dropped in the stir bar, poured in the yeast and sat the flask on a stirplate for 24 hours.

WLP-820 Lager Yeast Starter
 Once the krauzen had peaked and fallen I took the flask off the stirplate and set it in the refrigerator for a couple of days to help cold crash the yeast before decanting off the starter wort. I then repeated the steps to create a double batch of starter wort using the same proportions and split it equally between two 2 liter flasks. The first starter doubled my cell count to 200 billion viable cells, by splitting it in two and repeating the process using two stirplates and two starters at once I eventually ended up with the 400 billion viable cells needed to ferment this beer.

Cold Crashing 4 Liters Of Starter Wort
The yeast propagation process took a week to do and it had to be coordinated so it was completed in time for brewday when I would decant the starters, discarding the oxidized nasty tasting starter wort, and then pitch only the yeast. Since adding the decanting step to my yeast propagation process I have tasted a noticeable difference in the finished beer, enough of a difference that I decant all my starters now including the ones made using Ale yeast. Instead of making the starters the day before brewday now I make them 3 or 4 days before brewday, to allow the yeast enough time to settle out of the wort, it's a small adjustment to the brewing schedule and very easy to get used to.

60 Minute Full Rolling Boil
The grains were mashed for an hour followed by a two gallon vorlauf and a 45 minute lauter using a fly sparge with 174° F strike water until the kettle had 6.5 gallons of wort in it. The hop additions were put into the kettle at the start of the lauter and remained there until flameout to make room for the wort chiller that was used to drop the temperature down to 56° F prior to pitching the yeast. Near the end of the boil some WhirlFloc and yeast nutrient was added to the wort to help drop any proteins and cold break material out of suspension and provide the yeast with an energy supplement, both intended to reduce off flavors and promote a cleaner fermentation.

Wort Chiller And Pre-chiller Setup
During the course of the one hour vigorous boil a lot of Dimethyl Sulfide or DMS is boiled off, preventing the levels from building up too high and causing off flavors in the beer that smell like cooked or creamed corn. As the wort is cooled the DMS levels begin to rise again and if not cooled quickly enough the cooked corn off flavors start building up again in the wort and if left unchecked those off flavors will carry over to the finished beer. It's really important to cool the boiling wort down as quickly as possible after flameout to prevent the the formation of off flavors and also to greatly reduce the risk of infection. I did a simple calculation and found that cooling 5.5 gallons of 212° F wort down to 56° F requires removing around 6,800 BTUs of heat. My wort chiller with the pre-chiiler attached is capable of removing about 15,000 BTUs of heat and lowering the wort to 56° F in a little under 30 minutes. Even with the potential to remove such a high rate of BTUs from the wort the trick is to continuously stir the wort to keep it moving and in contact with the chiller coils or the insulating properties of the wort will greatly reduce the cooling efficiency.

1.057 Original Gravity Reading
Once the wort had been chilled and racked to the fermentor it was given a 60 second burst of pure oxygen to oxygenate the wort prior to pitching the WLP-820 starter yeast. The fermentation chamber had been precooled to 47° F a few hours before putting the fermentor inside it and a few hours later the temperature had leveled off and was held at a steady 50° F where it will stay for the majority of the fermentation. Nothing is better than bringing your wort up to a boil and then down to pitching temperature in as little time as possible, it's better for your finished beer and it also makes your brewday shorter.

Marzen Lager Samples Prior To Pitching Yeast
Based on several prior lager fermentations the primary fermentation and the diacetyl rest should be completed in about three weeks time and after that I'll rack the beer to a clean secondary and put it in the refrigerator and let the beer cold lager for 6 weeks so that the beer will be ready to drink in March 2013. Traditional Oktoberfest/Marzen Lager beers were brewed in the spring and fermented in caves over the long hot summer months to be enjoyed in the month of March, my approach is not historically accurate in that regard because I won't have the patience to wait 22 weeks before drinking this beer.

Hammerfest Marzen Lager
 This batch was carbonated and ready to start drinking the first week of March 2013 and it tasted amazingly good. I love the good clean malty flavors and aromas of a cleanly fermented Marzen as much as I love some of the hoppiest IPAs I brew. When the glass is poured and you're ready to take a sip you can smell the malt aroma and taste the clean malt flavors without any hint of yeast or other fruity esters. The carbonation, head retention and mouthfeel all worked together perfectly and the finish was pleasant, not at all bitter or cloying with hints of malt that made me want to drink another.

I have another 2.5 gallon corny keg of this beer sitting on 12 psi of Co2 in the refrigerator and it'll be ready to drink in about 5 days. I moved the beer from the fermentor to sanitized corny kegs after 3 weeks of fermentation at 50F and another week of cold crashing in the refrigerator at 36F. The corny kegs were filled with the 36F beer and then placed in the fermentation chamber at 50F for another 3 weeks to allow the beer time to condition. All these extra steps and extra time produced a really clean tasting beer that showcased the flavors and aromas of the malts used in the beer, this recipe is a keeper and I look forward to brewing it again then next time I decide to treat myself to a great tasting lager beer.

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