My first brew day is approaching and in preparation I have been monitoring the temperature of the room I plan to use.

Initially I was seeing daily fluctuations from 16C to 25C as the heating came on and off. Obviously that wasn't going to be suitable so I turned the heating off in this room and now have a fairly consistent 16C to 17C which seems a little cold.

Will this ambient/room temperature still be suitable as the fermentation process will generate heat itself?

3 Answers 3


In the first couple days of active fermentation, the beer itself can rise to as much as 10F over ambient temp. That's why it's always best to chill your wort to a bit below fermentation temp and let the activity of fermentation bring it into the correct range. 17C would be an excellent temp for the beer. Be sure that you measure the beer temp, not the room temp. Thsoe stick on fermometer strips work well and are remarkably accurate.

  • +1 - I happen to have a no-touch IR thermometer and I've been using it to measure my ferm temps. The stick-on strip has always been within 1F of the reading from the gun. So yeah, those strips are good. The batch I have going now was my first time using my new chiller and I didn't chill far enough and learned the hard way about pitching too warm. I pitched at about 77F and the yeast took off like rockets. I had to move it to my basement to slow them down. So definitely chill to a few degrees below pitching temps before pitching.
    – JackSmith
    Jan 20, 2011 at 21:54

Fermentation will generate some heat relative to the activity of the yeast; however if you can provide a constant and suitable ambient temperature then there are other aspects of brewing that should probably be given priority above fine-grain temperature control.

Since you've got a stable room temp (a "good" temp is really yeast/style dependant) then you should be fine. Go through your brew day and focus on making the beer correctly, then slap a fermometer on the fermenter and just observe what happens. If your first couple batches are anything like mine then you'll make, and learn from, many small mistakes initially--so focusing on perfecting one aspect probably won't payoff until you're comfortable with the whole process.


To answer your original question, yes, the ambient room temperature you have will be perfectly fine for ale fermentation.

For the sake of simplicity, I would suggest cooling your wort to the lowest recommended temperature your yeast indicates (e.g. 18C or so) and begin fermentation there. The yeast will bring the heat of the wort up some as it ferments but the beginning temperature combined with the slightly lower ambient temperature will keep it within a good temperature range.

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