General question on fermentation temps

[Sidman]

I noticed that my fermentation closet is getting cooler with a recent cool front and I will need to likely install a heater to keep the temp constant.

My question is How important is it to keep the temperature the same vs keeping it below a certain point.

i.e. I have been fermenting at 68 degrees Fahrenheit but the bottom end is going down to as low as 65 in the evening.

Will that cause taste issues or yeast problems?

 

[sikkingj]

At 65 degrees you will be fine. In general the lower the temperature the slower your yeast works...


Sent from the window of an airplane...

 

[Cyclman]

As long as you are in the yeast temp range, you're fine.

 

[12thHoleBrewer]

From what I've heard on the Jamil show, those guys feel that maintaining a constant temp is important. They said that even if the temperature range stays within guidelines, a temperature that fluctuates back and forth even just 3° (warmer during the day, colder at night). can put stress on the yeast and cause it to produce some off esters or off flavors. I only learned of this recently myself and in the past have brewed a number of beers that were kept in a room that had different temperatures during the day versus night. My opinion is that with yeast, just because stress can happen doesn't necessarily mean it will happen. With my past beers that I brewed, I did not detect anything that made them bad or undrinkable. Yes, it is possible that a certified judge could possibly have been able to pick up some off flavors that are inconsistent with style guidelines but to me, I was satisfied with the end product. That being said, I am going to try and ferment my beers at a stable temperature going forward just in case.