Links, to spare some bandwidth:

West County (MP4, 35.4 MB) | West County 2 (MP4, 73.0 MB)

85% efficiency on a 1.059 beer, though… I do love my Barley Crusher.

This has always puzzled me. Wouldn’t it be in Wyeast and White Labs’ interests to advise pitching two – or more – of their products? Regardless, are they correct in their recommendations, or should homebrewers pitch the same amount of yeast as professionals? What are the effects of varying the pitching rate, and how noticeable are they?

Based on a rather heated discussion in the Northern Brewer forums, there is both a great deal of interest in these questions, and no consensus on the answers. A recent collaboration between Basic Brewing Radio and BYO attempted to address these issues, but was limited in both the number of participants, and the applicability of their results (since each brewed different beers). To get around these logistical shortcomings, I propose the standard engineering solution: let’s throw money at the problem.

Briefly, what I plan to do is brew a batch of beer (a tentative recipe is below), split it into two fermenters, and pitch one at the standard rate, and the other at the rate that would result from pitching a vial or pouch of commercial yeast (about 0.3 billion/L-°P). I’ll then ship three samples, identified only as A, B, and C, to as many tasters as possible. Each can then do a blind triangle test, fill out a standard survey form (also below), and return it. Ideally there will be enough respondents to be able to perform statistical analyses on the data.

If you want to get involved, it isn’t too late. Either sign up via the NB forum topic, or Contact Me directly.
 
 
Update: 03 March 2010

The test beers were brewed today. I began by building up the starters from 10 mL of slurry that was 52 days old (approx. 25 billion cells). The slurry was pitched into 500 mL of starter wort (~50B); after 24 hours this was split evenly between 400 mL (~50B) and 2.4 L (~125B) starters. These were allowed to ferment to completion, while being shaken as often as possible, then placed in a refrigerator 16 hours before pitching. All propagations were conducted in wort that was 8-9°P, with about two-thirds of the gravity coming from a mash of Castle Pilsen malt, supplemented with Briess Pilsen DME.

The actual brewing session was uneventful, although I underestimated the mash efficiency slightly. The wort was chilled to 17°C (63°F) and split between two 6.5 gallon plastic bucket fermenters. Each ended up with just over three gallons of 14.6°P (1.059) wort. They were aerated for 10 minutes with an aquarium pump and stone, then the decanted starters pitched and the fermenters placed in a room with a steady ambient temperature of 62°F.

The resulting pitching rates are 0.29 and 0.73 billion/L-°P, although the second significant digit is obviously not justified.
 
 
Update: 16 May 2010

Results, including the observations of 37 independent tasters, have been posted: Yeast Pitching Rate Results
 
 
Downloads:
Caramel Camel Amber Ale (PDF) | Sensory Evaluation Form (PDF)

I’ll be in St. Louis from December 26^th until January 1^st. To anyone I won’t see, happy holidays!

• My go-to “house” recipe, Behold a Pale Ale.
• My other house recipe, Man in Black Lager. It’s a sort of bastardized American Schwarzbier-Vienna Lager hybrid. I can easily ferment lagers in the garage right now, but maintaining lagering temperatures for any length of time would be a lot of effort. Fortunately I only need to lager this for a couple weeks.
• A doppelbock. I’d really like to have one on tap in the spring, which means I’d need to get cracking on it, but I think 2-3 months of lagering is probably impractical under the circumstances.
• A single-hop IPA. I haven’t decided exactly what yet, but it would most likely be Centennial or Columbus.
• A “redemption” porter, to avenge the one that I brewed a couple months ago and subsequently let pick up a (mild) Lactobacillus infection.