October 2, 2011 By Alastair Hewitt
Around this time of year Oktoberfest beers are everywhere. The authentic version of this style is a lager brewed in the spring and matured at cool temperatures during the warm summer months. The beer was saved in this manner to celebrate the harvest and the beginning of the new brewing season.
This style poses many challenges for the average home brewer. Keeping a beer cool, typically as close to freezing as possible, will take up valuable refrigeration space when is is most needed during the summer months. Lager brewing also takes additional effort. The cool fermentation temperature require a much higher yeast pitching rate and accurate temperature control. Even at these low temperatures an infection is possible and the longer lag phase, sometimes up to 48 hours, can benefit uninvited guests in the form of bacteria.
This all sounds a little intimidating, but there are some short cuts with the help of a hybrid lager yeast. The particular strain of interest here is used in making the classic California Common, or Steam beer. This is a true lager yeast, but has the ability to work correctly at higher temperatures. It can also develop a clean taste without the need for extended cold conditioning. This yeast is therefore a good choice for lager brewing in the warmer months due to this versatility.
Another consideration in making traditional German lagers is decoction mashing. This involves removing the thick part of the mash and going through a quick saccrification mash followed by a boil. This portion is returned to the rest of the mash to raise the temperature and then the process is repeated. This is a fairly time consuming activity and not really necessary given the great performance you can get from Valley Malt.
The recipe below is made using a single step infusion mash and you will find this works great at extracting all the flavor you need from the grain. The grain bill is made up of Valley Malt Pilsner and Munich malt. Oktoberfest beers are often made up of all Munich and/or Vienna malts. The Valley Malt Munich is towards the dark end of the range, so the Pilsner is needed to keep the color within range. Some people add crystal malts to Oktoberfest, but this is not a traditional ingredient in authentic versions. Due to the higher kilning temperature, you will get some caramel notes from the Munich malt, so think twice before adding any.
Hopping rates should be in the 20's of IBUs. This recipe aims at the center of this range (24 IBUs) by using the higher alpha German grown Magnum hops. These can be substituted for one of the Hallertau varieties, but will require about twice the amount of bittering hops to get to the same level of alpha acid. The bittering hops are added directly to the kettle during the sparge. This is know as first wort hopping and helps bind some of the more volatile aroma compounds in the hops before the wort reaches boiling temperatures. The boil should be a full 90 minutes to help develop the rich malt flavor. More aroma hops go in at 10 minutes from the end and then right at the end of the boil.
Make sure the wort is cooled to below 60*F before pitching the yeast. This can be difficult given the warmer tap water temperatures in the summer. If the cooled wort is still over 60*F just place the primary fermenter in the fridge for a couple of hours to drop the temperature. Make sure to aerate well and pitch plenty of yeast. This will typically require a large yeast starter to build up the necessary quantity needed for a lager fermentation. One easy way around this is to brew another beer with the same yeast and pitch the slurry. The hybrid lager yeast used in this recipe can behave very much like a typical clean ale yeast when used in the 62-66*F range. Brew up a batch of ale that would normally use a vial of WLP001 or 1056 and you should have plenty of yeast.
Valley Malt Oktoberfest
Batch Size: 5 Gallons
Target OG: 1.058
Target FG: 1.014
Target Bitterness: 24 IBU
Target Color: 14 SRM
Alcohol: 5.8 % ABV
Primary Fermentation: 14 days (below 60F)
Secondary (lagering): 4 weeks (below 50F)
Keg, or bottled condition for 3 weeks
Efficiency calculated at 70%.
6 lbs Valley Pils (or Pale) Malt
7.5 lbs Valley Munich (or eq)
1.25 oz Magnum hops (10-12% AA)
WLP810 San Francisco Lager, or Wyeast 2112 California Lager
Single Step: Saccrification Rest
Thickness: 1.25 quarts / lb
Target Temperature: 150*F
Mash Time: 75 min
-Start 90 minute boil
@ 90 min remaining add 0.5 oz Magnum
@ 10 min remaining add 0.5 oz Magnum
@ flameout add 0.25 oz Magnum
Ferment with a hybrid lager strain anywhere between 48 - 60*F. If fermenting in the lower end of this yeast make sure to raise the temperature in the last couple of days of fermentation to help reduce diacetyl.
Store beer at cool temperature for around a month. This can be in a regular fridge without any temperature control (35-38*F). Make sure it doesn't freeze!