Fermentation Temperature

jfrostp · 12-27-2009, 10:04 PM

This is a simple question, but I haven't been able to find the answer yet -

If a yeast strain is rated to be happiest between 65F-70F, does this mean I should keep my fermenting brew in a room that is 65F-70F, or does it mean I should keep my fermenting brew in a room that is 60F-65F to account for the raised temperature inside the primary during fermentation?

Thanks!

MurderMittenBrewing · 12-27-2009, 10:12 PM

You want to keep the temp of the fermenting wort within that range. Assuming your ambient temp is colder than the wort, the wort will initially loose temp during the lag before fermentation really takes off. Make sure the wort doesn't get so cold that the yeast stalls.

Then the wort will increase temp as fermentation gets going. How vigorous your fermentation is will determine how much of a temp increase you experience. You can control this increase by dropping the temp of the ambient temp around your fermenter.

So, I guess the answer is yes to both of your questions.

jfrostp · 12-27-2009, 10:15 PM

Ok, got it. Thanks MurderMittenBrewing!

MurderMittenBrewing · 12-27-2009, 10:20 PM

No worries. I've found that temp control is one of the most difficult aspects to master when you begin brewing. What yeast are you using? Fermenting at the colder/warmer end of the scale can result in desirable/undesirable flavors.

For instance, if you push Safale US-04 to the top end you'll get some really nasty bubblegum aromas. If you push Wyeast 1010 to the top end you'll get a really nice citrus flavor in your wheat beer.