Just out of curiosity

[william_shakes_beer]

I am curious to understand why this happened. I like both batches, but would be interested in learning how these differences occurred.

I did a 10 gallon AG batch of a Guiness stout clone recipie. I used black patent malt, acid malt and chocolate malt, among others. I did a full boil that resulted in just over 10 gallons. Pitched the same yeast to both, and split it into 2 5 gallon fermenters. The first i placed in my ferm chamber under temp control. The other I placed in the shower of a spare bathroom in the basement. Both were fermented 30 days, followed by 30 days bottle conditioning. Popped open one of each last night. The one that was under temp control gave a good sense of acid and virtually no peat/smoke/char that usually results from black patent. The one with no temp control had no acid and a strong sense of char, almost too much.

I realize they will both change over time and I look forward to experiencing both. However, I would feel a lot more confident if someone could help me understand why ferment temp would have such a strong affect on the acid malt and smoke/char tastes.

 

[william_shakes_beer]

I'll bump this one just once and then let it sink slowly into oblivion.

 

[wegz15]

Yeast give off certain flavors at certain temps. Not sure if that has anything to do with it, but that would be my best guess. Especially since all other factors were the same. Well yeast pitch rate might have been off.

 

[cooper]

I agree that it probably has something to do with ester production and how fast the yeast ferment the beer. In the shower, the temp probably got up to around 75F at least during peak fermentation, which one do you like better?

Ester production is the same reason why some people like to ferment in a bucket or the boil kettle during primary fermentation (about a week at most) and then rack to a glass carboy for secondary; it just seems to produce more esters in an open/higher temp fermentation. Again, it all depends on the style you're brewing and what you like. Great experiment though! We need more of these.

 

[william_shakes_beer]

I like the one that was under temp control better. For me the trademark guiness taste is the acid malt.