Oatmeal Stout - Split Recipe

This post was brought to you by my sister Julie, Christmas, and an Austin Homebrew Supply giftcard.

Following the yeast experimentation I decided to use my 20 gallon brew pot to do some ingredient tinkering between two 5 gallon batches. The 10 gallon batch of oatmeal stout would begin with the following grain bill:


Grist

19 lbs of 2 Row Malt
2 lbs of Flaked Oats
1.5 lbs of Victory Malt
1.5 lbs of Chocolate Malt
1 lb of Roasted Barley
1 lb of Caramel 75L

Mash
155°F for 75 Minutes

Extract
none

Hops in the Boil
3oz Kent Golding (5.4% AA) for 60 Minutes
3oz Kent Golding (5.4% AA) for 60 Minutes

Additional Ingredients
Whirlfloc
1lb Honey - Carboy 2
2oz Unsweetened Baking Chocolate - Carboy 2
12oz Blueberries - Carboy 2

Yeast Packages
2 - White Labs - English Ale (WLP002)

Yeast Starters
2 - 700mL (1 DME/4 H20) Stationary - 27 Hours


Fermentation
Primary - See Below

Dry Hopping
None

Cold Crashing
33°F for 1 Weeks

The differences in the two batches came after the 5th day after I pitched the yeast, when the fermentation slowed considerably. This slowing, and subsiquent hydrometer reading of 1.018, told me that the yeast finished fermenting the majority of the more complex sugars, and it was time to add the simple sugars contained in the blueberries and honey. Yeast ferment simple sugars easiest, so naturally they chose to ferment them first. If they are added too early it could make it difficult for the yeast to ferment the more complex sugars later.

"See Below"...that can't be a good sign. Because of this fermentation I will be creating a "Lessons Learned the Hard Way" page, and update it with issues like this. Where my fermentation was taking place was too cold, so my temperature controlled deep freezer was of no help. I had this genius idea to pitch warm at 75°F, and let it gradually fall to my target temperature of 65°F. The problem was that I insulated the carboys, and apparently did too good of a job doing so. With the exothermic yeast activity it took over a day for the beer to get into the yeast's 65-68°F comfort zone. I won't know how this affected the final product, but in the repeatable/predictable world of brewing these issues need to be ironed out. In the future I will have to find some equipment to do warming temperature control.

Yeastly Experimentation - Kolsch vs Trappist - Tasting

The fermentation of these beers went off without a hitch. I was able to keep them both at temperatures that made them happy, and when you keep yeast happy they make you happy. With such a delicate grain bill any off flavors should be easily detectable, and I think both are very clean tasting.

Kölsch (WLP029): The kölsch, on the right, seems to be slightly paler and clearer than its trappist counterpart. The hop flavors are very front and center in this beer, and just as quickly as the taste appears it is gone. Its amazingly crisp and clean finish makes you wonder if you even took a sip.

Trappist (WLP500): Unlike the kölsch, the trappist yeast imparted lingering estery flavors to the beer. The taste of bananas and spices are definitely present, but because it wasn't fermented at the upper limit of its temperature range these flavors are a little subdued. This is a very good thing, because the light grain bill and low ABV wouldn't have been able to balance out a heavier ester profile.These flavors really linger on your tongue (and in your burps), and created a much more complex beer.


This experiment turned out exactly the way I expected, and in the brewing world that is a win. Now that I have predictability down, I'll have to start working on repeatability. Until then...I have a lot of beer to drink, and any help would be appreciated!