Kurtoberfest

Every year I've been brewing, I've made an Oktoberfest/Märzen. For those who don't know, the style is traditionally called "Märzen" because it is made in March, which you might have noticed is quite a while before Oktoberfest (which is, strangely, in September). This beer is a lager, which means it's fermented slow and cold, and then undergoes an extended period of lagering, which is fancy brewer talk for "cold storage". Lager comes from the German verb lagern meaning "to store". For this beer, the lagering is quite long. I never seem to have my act together in March, and this year I wasn't really ready until early May.
Many beers served at the actual Oktoberfest in München are not a Märzen, and are instead a paler lager, maybe because they are more drinkable with less residual sweetness, but I like to brew to style on this one.

Kurtoberfest

Batch size: 12 gallons
Expected efficiency: 75%
Target OG: 1.054
Target FG: 1.014
Color: 10 SRM 

Grist:

• 8# Pilsner Malt
• 7# Light Munich Malt
• 5# Vienna Malt
• 2# Crystal 60L Malt

Mash:

• Saccharification - 151°F for 60'
• Mash out - 170°F for 10'

Boil: 90 minutes total

• 3 oz. Mt. Hood (leaf, ??% aa) at 60' to ?? IBU
• 1 oz. Mt. Hood (leaf, ??% aa) at 20' to ?? IBU

Fermentation:

• Chill to 63°F, rack on top of yeast cake of Wyeast 2124 Bohemian Lager from Bitter Pils To Swallow
• Cool quickly to 50°F, ferment 2 weeks
• Free-rise to 61°F over 5 days for diacetyl rest
• Rack off the trub and crash-cool to 35°F, add some Biofine Clear
• Lager 4 months at 35°F

You'll notice that I'm reusing the yeast cake from the previous lager. I didn't have time or really want to do the large starter required for a 12-gallon batch of lager. I've read various opinions on putting your wort right on top of a full yeast cake. Some folks worry that because you have such a huge cell count, there won't be any yeast reproduction. Yeast reproduction serves two purposes to the brewer. First, it ensures that there are healthy cells available. Second, many of the flavor profiles associated with particular beers, such as English ales and Belgian beers, are from esters or phenols produced during the reproductive phase of fermentation. Because a lager fermentation is supposed to be very clean (meaning it doesn't have any of those esters or phenols), I certainly wasn't worried about the second one. I'm also pretty sure that the yeast weren't too beat up from that Pilsner fermentation, so I'm throwing caution to the wind and just going for it. If this were an ale, I might be more concerned, since a huge yeast cake will frequently lead to very vigorous fermentation, but with the temperature control in place, I'm not worried about blowing out the airlock at 50°F.

I'm also using more of my homegrown hops for this, including for bittering. I really needed to get through the last of my Mt. Hoods from last year's harvest, so they all went in to this beer.

As for the lagering process, I recently read about a rule of thumb from Greg Noonan's book New Brewing Lager Beer that says you should lager 7–12 days per 2° Plato. I managed to hit 1.052 with this beer (not sure why I undershot, especially since I was only aiming for 75% efficiency), which is about 13° Plato. So if this were any other beer (i.e. if I wanted to drink it earlier), I'd want to lager it between 7-12 weeks. I may apply this rule to the Pils, which has been lagering about three weeks already.