#4 Kolsch

I had anticipated today being the day I would brew an English Oatmeal Stout but the yeast I had ordered (Wyeast's 1028 London Ale) I ordered a little too late. Instead I chose to go ahead and brew the Kolsch I had planned a while ago. 

Kolsch

Batch Volume (Gal): 5.00

Pre-Boil Volume (Gal): 5.66

Total Grain (Lbs): 8.38

OG: 1.054     Anticipated FG: ~1.012     Anticipated ABV: ~5.5%

IBUs: 22.9

SRM: 3.4

Brewhouse Efficiency: 85%

Boil Duration: 65 min

Grain               (Lbs/oz.)       (%)

Pilsner                  7.5             89.5

Wheat Malt         7 oz.           5.2

Munich Malt       7 oz.           5.2

Hops                (AA%)        (IBU)         (Oz.)         (Boil [min])

Spalt                   3.9            16.9             0.9                  60

Hersbrucker      2.4             5.9               1                     30

Yeast

Wyeast 2565 German Kolsch (repitched from Alt yeast cake and krausen)

Water

1 tbl 5.2 pH stabilizer (in mash)

1 tsp Calcium Chloride (65 min)

3 tsp Calcium Sulfate (65 min)

1 tsp Irish Moss (10 min)

1/2 tsp yeast nutrient (10 min)

I mashed in at 150 F , and the temperature dropped a degree to 149 F during the 60 minute mash. I collected about 5.13 gallons after sparging with 1.5 times the original strike water volume and came up short about 2 points of my targeted original gravity. 

I'll have to remember in the future that with beers made with a small grain bill, I'll have to plan on sparging with greater than 1.5 times the original strike water volume. I've come up short when collecting my targeted original gravity and targeted pre-boil volume a few times with the last few low gravity beer batches, and it would be nice to sparge with too much water (leaving sparge water in the mash) rather than letting the mash run dry and missing out on gravity points and/or pre-boil volume.

Fortunately after sparging with an additional 2 gallons of water at 170 F, I collected 5.66 gallons in pre-boil wort while at the same time exceeding my targeted original gravity. Now with two beers under my belt with the new grain mill, I'm starting to think that the mill is greatly improving my efficiency, by about 10 percentage points on average. I had to remeasure the gravity of my wort a few times before I was willing to believe I had collected so much sugar (after collecting about 2/3rds of a gallon less wort than I usually do during the sparge). It'll be interesting to see if my efficiency continues to be this high with future batches, possibly allowing me to save a few bucks by buying less grain.

The only problem I ran into today was the cloudiness of the wort as I collected from the mash in my boil kettle. I was concerned initially that it was unconverted starch, but after tasting the wort I don't think that could be the case. The recipe did include 5% wheat and is an extremely light beer. It's possible that the cloudiness was simply the result of protein from the wheat malt that was more visible in such a light colored wort. Hopefully the boil, the addition of irish moss, and filtration after many days of lagering will clear this beer and leave it looking bright and clear.

After only about an hour, the yeast already seem to be active. Fermentation isn't exactly vigorous yet, but to have such a short lag time is very encouraging. The fact that I repitched the Wyeast 2565 Kolsch Ale yeast from a batch of beer that was wrapping up fermentation may have a lot to do with how quickly this batch began fermenting. The majority of the yeast slurry that I took from the Alt was from the krausen on top of the beer, with very little of the yeast coming from the yeast cake at the bottom of the fermenter. This would likely indicate that that krausen was full of actively fermenting yeast whereas a yeast cake would be full of recently dormant yeast that would take some coaxing into fermenting a new batch of beer.

I transfered the Alt into a keg in order to leave the yeast behind for the Kolsch. Hopefully disrupting the beer will not result in any off flavors in the Alt. I'm somewhat confident that the Alt will be able to clean itself up however since the Wyeast 2565 Kolsch ale yeast is a poor floculator, and there was still plenty of yeast left in suspension when I transferred the Alt into the keg. After about a month of lagering for both the Alt and the Kolsch, I should be able to filter both kegs and be left with two sessionable German ales appropriate for spring drinking.