Lager Yeast Performance

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Lager Yeast Performance

Postby BillyBock » Tue Mar 01, 2005 8:19 am

A question for the collective experienced with lager yeast performance...

Q: is there a typical fermentation rate (at normal lager temps), as measured in either degrees Plato or specific gravity units per day? If no typical performance, are there any published data on this subject by yeast strain?

My interest in knowing this is to be able to time the diacetyl rest without taking daily samples to confirm when it should be started. If I know it ferments X degrees Plato per day, then I can estimate when I should check the gravity to confirm the start of the diacetyl rest. It also allows me to estimate the target date to reach terminal gravity and keg it--which then allows me to start planning the next brew day so I can always keep my conical full :D

Over the last 18 months I've concentrated on making lagers, and I've used a variety of strains--Safale S-23, Superior, WLP820 O-fest, WLP830 German Lager, WLP833 German Bock, WY2206 Bavarian, & WY2308 Munich.

In my experience the reduction rate seems to be about 2.5 to 3 gravity units per day, or about 0.75 degrees Plato per day. I wasn't running a controlled experiment; however, it seems yeast strain didn't matter greatly--as they all had the same relative performance. However, that may be due to the fact that all the yeasts I used were of Bavarian origin. Anyway...I'd be interested in comparing notes.

For anybody that read this just starting to get into lagers--if I were to select 2 strains for my continuous duty in making my house beers those would be: WLP830 German Lager & Safale S-23 (dry). They were easy to work with (ie. minimal diacetyl production), worked for a wide variety of lager styles, but above all tasted crisp & clean so the flavors of the ingredients shown through.

v/r
Bill
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Interesting topic

Postby Azorean Brewer » Tue Mar 01, 2005 1:11 pm

Bill,

What temp's are you fermenting at, both primary (how long) and secondary (also how long). I have been stumbling through the lagering process not very scientifically, primary starting at 70F for one day, putting it in a chest freezer at 55F for two days, and dropping it to 45-50F for 5 more days and then secondary for 2 weeks up to 3 months (for my Oktoberfest) ... write back OK?

Regards,

Paul.

P.S. I have been meaning to ask what's the "v/r" stand for?
"I drink therefore I am"
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Lager Temps

Postby BillyBock » Tue Mar 01, 2005 8:47 pm

Hey, Paul:

I pitch cold and then I'll carry out the primary between 50F & 55F. Once I'm done w/ the D-rest, I begin lowering to 36, and then it gets kegged. I lager in the keg at 36F at 1 week per 2 deg Plato of OG (got that from Noonan's book). So your standard Pilsner (12 deg Plato, or OG=1.048) will lager about 6 weeks. With the primary time it's usually about 8 weeks from grain to glass.

Oh, and "v/r" means "very respectfully".

v/r
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