I was wondering what are the effects of fermenting a lager at room temperature as now I don't have any way to keep my fermenter at the low temperatures required.

I have read that when yeast ferments at higher temperatures it produces more esters and develops fruity flavours. One of my favourite beer styles is Oktoberfest, has anyone tried to ferment an Oktoberfest lager at room temperature?

  • 1
    Note: "lagering temperature" is different from the temperature you ferment a lager at. Lagers are fermented cold, but then they should be lagered even colder than that.
    – Jeff Roe
    Apr 10, 2016 at 1:50
  • You may want to have a look at a couple of Brulosophy xbmts related to lager fermentation temps. brulosophy.com/2016/02/08/…
    – Anigel
    Apr 10, 2016 at 18:42
  • WLP cream ale (080?) is a mix of lager and ale yeast, meant for ale temps, similar to California common, when i fermented with it at low 60F s High sulfur smell, but cleaned up after a week, when bottle conditioned. no fruity esters. very clean and lager like. Im waiting on a batch that was done in the High 60Fs to see the difference (same recipe for both)
    – jsolarski
    Apr 11, 2016 at 21:15

3 Answers 3


In general, fermenting lager yeast at room temperatures would result in off flavors due to esters, diacetyl, and other components. The "California Common" is an exception to this, and the standard explanation is that the yeast strain (Wyeast 2112 or WLP810) used for this style of beer can handle higher temperatures than most lager strains. Who knows, however, you might wish to experiment with higher than lager temperatures with other strains to see what you discover!

Incidentally, if you can control your fermentation chamber, the brulosophy method let's you start fermentation at lager temperatures and allows you to increase the temperature slowly up to ale temperatures, which results in a faster fermentation without off flavors.

  • Does fermenting a lager at ale temperatures result in diacetyl as a problem? Wouldn't that get 'cleaned up' like in an ale yeast ferment, or like a lager yeast during a diacetyl rest?
    – brewchez
    Apr 12, 2016 at 12:03

Most lagers need to ferment below 55°F during growth phase to reduce esters and fusel alcohols.

Diacetyl Rest Towards the end of the feeding phase (last couple days of primary) the temperature is raised to low ale temps 65-72° for a couple days, this gives the yeast a boost in metabolism to clean up Diacetyl. So heat is a good thing at one point in the fermentation.

Then lagering can be slowly introduced, at about 1° drop an hour.


The result is strain dependent for sure. In general, more esters is the prevailing wisdom, but more than an English ale yeast at room temperature? I've never seen the experiment done side by side so who knows. Experimentation would be needed to really suss it all out.

Keeping some of the 'hybrid' strains as cool as possible can give some very clean tasting ferments. Enough to pass off an Octoberfest as tasty even if not the purest of methods and flavor profiles. You might find you like it that way.

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