Ale yeast at lagering temps?

[StirItUp]

Perhaps a dumb and previously-asked question... Couldn't find a thread in search.

Anyhow, I put 5gallons of an American amber in a secondary after two weeks in the primary. It fermented a little warm in the primary-- heat wave up here, so it got to about 75-80 in my basement.

I don't recall the brand of yeast I used, but it was a regular ale yeast. So I put the amber into my lagering fridge (55-59 degrees) -- do you think it will halt fermentation, or will the yeast continue to ferment at a slower rate, leading to a lager-y type clarity/taste? Curious as to thoughts, if I'm better off taking it out of the fridge... I will! Amber is the glass carboy.

 

[usfmikeb]

The brand and strain will really determine what happens. For example, the starting range for US-05 is 59 degrees, while the starting range for WLP060 is 68 degrees. Keep in mind that those ranges are for optimal fermentation, so I'd imagine that it is still fermenting. Therefore, the better question is whether the yeast is stressed at this temperature.

 

[osagedr]

After a couple of weeks of very warm fermentation, it was likely completely finished fermenting. What did your hydrometer tell you?

If you hadn't yet hit FG, you probably won't now, although it depends on the yeast strain you used.

My guess is that fermentation is complete and now you are just conditioning your beer.

 

[usfmikeb]

Just for clarification, when I say still fermenting, I mean the yeast is cleaning up some of the byproducts it made during a warm fermentation.

 

[StirItUp]

Thanks gents. I did hit FG in only two wks in primary- probably due to the high temp/rapid fermentation. But I thought conditioning started only after - or does it start after fermentation slows & the yeast is just processing byproducts?

 

[azoteman213]

Hello StirItUp. After the yeast finish eating the easily accessible sugars int he wort, they begin looking for other things to feed on, in this case the diacetyl they have produced during there aerobic stage (when they reproduce). I hear of people doing a diacetyl rest during the final stages of fermentation, so they are consuming the diacetyl at that point, and they continue to consume it after the fermentation subsides.

The efficiency of the conditioning ("cleaning") phase depends on many factors, such as initial fermentation temperature (too high and probably there is too much diacetyl for the yeast to consume anyway), the amount of yeast remaining in suspension after fermentation is completed (if most of the yeast is dormant at the bottom and not contacting the wort, it wont be able to clean as rapidly as if it was suspended). The latter point addresses more directly your question. If you lower the temperature too quickly, the yeast may become shocked and fall out of suspension, leaving you with less yeast to clean up.

The point is, if you lower the temperature of your yeast to a temperature lower than its recommended range (especially if you do so quickly), you will have less yeast in suspension to finish the job and it may take longer to clean up the beer. I do not know the specifics of your yeast, but upper 70's temperature sounds kind of high and there may be too many by products for the yeast to clean up after.

I'm sorry if my answer isn't a straight forward "take it out" or "leave it", but it is really dependent on the yeast you are using and the time you are willing to let the beer age.
I hope this helps for your next brew and always remember to RDWHAHB (relax, don't worry, have a home-brew).

P.S. By the way, how did this turn out?