Monday, May 18, 2009

Yeast Experiments Part I

I have a back-log of post topics (including 2 recipes), but I thought I would write about my recent yeast experiment. I've acquired a 13 gallon brew kettle which means I can now brew 10 gallon batches. So, I thought it would be fun to repeat the 15 Mile IPA and split the batch with two yeasts; Safale US-05 (the original) and Safale S-04.

Both dry yeasts were started the morning of brewing. Interestingly, the 04 began to sediment (flocculate) before the starters were pitched while the 05 had an even turbidity. I have read that the 04 could have violent starts, but I have used it before without problems. The 05 is an "American Ale yeast" and the 04 is an "English Ale yeast."

The 10 gallons of cooled wort were split into two primary fermenters and locked up at about 9:00pm. The following morning, this is what I woke up to...

Actually, Mt. Kraeusen formed after I pulled the foaming airlock from the lid. This was the 04. The 05 was chugging along nicely, but not had no inclinations of escaping.

After 2 days the 04 has virtually stopped bubbling (the foaming had ceased after the first day and I was able to reinsert the airlock) while the 05 continued at a steady pace. I kept them in the primary for a week until the 05 finally started to slow. I'll talk about the transferring, SG and my final conclusions in the next post...