Fermentation Tempatures? Best Temp? How important is stable Tempature?

What is the best fermentation temp?, for a lager or ale?, how important is it to keep the tempature stable?... I have now started to brew at 18C. Using the water bath method (Thanks Yooper).

Will my beer be much improved because of stable tempatures?

Thanks guys!

More important than stable imo is range. Keep at 60-65 F. You will have to look up the conversion. Based on experience only and without any science to back it up, I bet that fluctuation from 60 to 65F will be a lot better than a solid 70F for an average ale yeast. If you can try to get it to be somewhat stable for 5 days then you win. After that, the impact of wild high temps will affect the beer only a small fraction of what it would do in that 5 day period.

I love this post! It made me happy to read. This is a bit like asking, "What is the best tool?" It depends on the job and fermentation temp depends on the yeast and what you're trying to achieve.

Check out the yeast companies website for a recommended temp range. Then as a general rule, ferment on the low side to produce a beer that has less of the flavors in the yeast description and on the high side to produce more.

Also, the best tool is the hammer... obviously.

badbrew said:

More important than stable imo is range. Keep at 60-65 F. You will have to look up the conversion. Based on experience only and without any science to back it up, I bet that fluctuation from 60 to 65F will be a lot better than a solid 70F for an average ale yeast. If you can try to get it to be somewhat stable for 5 days then you win. After that, the impact of wild high temps will affect the beer only a small fraction of what it would do in that 5 day period.

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great information badbrew. I was wondering the same thing. glad to learn that the first. five days are the most important.

Hi, Thanks badbrew. It's a kit I am brewing from, and on the kit instructions it says 18C - 21C. (64F - 70F)
I have the fermenter in a bath of water (Plastic Container), and I am using a 25watt fish tank heater to hold the line at 18C.
Before this I been using a heating belt and my temps were up and down like a jockey's balls.
Will this definatly impove my beer. I am no expert but it seems already to be a much more controlled balanced fermentation.

rhinofarts said:

Hi, Thanks badbrew. It's a kit I am brewing from, and on the kit instructions it says 18C - 21C. (64F - 70F)
I have the fermenter in a bath of water (Plastic Container), and I am using a 25watt fish tank heater to hold the line at 18C.
Before this I been using a heating belt and my temps were up and down like a jockey's balls.
Will this definatly impove my beer. I am no expert but it seems already to be a much more controlled balanced fermentation.

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Yes, gaurenteed.:fro:

Just watch out for air temps higher than 18C and verify that the fish tank thing works with another thermometer. Also watch the beer temperatures. That is what you are concerned with, not the bath. They will be higher than the bath for the first week. Since 64 is on the low end, it may be actually 70F in the beer, so check it after the krausen starts to build up (maybe 20-40 hours in). You may want to change the heat to get it to the middle of the yeast range. If the FG is not close enough after a few weeks, bump it to the max temp or even a little higher (70-75).

Temperature control is most important from the time you pitch your yeast until about 3 days into the fermentation. It is during this time that the yeast produce most of their flavors. After three or four days, it's a good idea to raise the temperature to help the yeast attenuate fully and accelerate the metabolism of intermediate fermentation products. 18C is a very good fermentation temperature for most ales.

As far as stability goes, some people swear that this is even more crucial than the average fermentation temperature. I am not sure I agree with that assessment, but is true that swings can cause problems, such as premature flocculation or blowoff.

ArcaneXor, after 3 days at 18C, what would you bring the temp up to then?

jockeys aren't castrated? or do you mean balls in the sense of great big parties at manor houses, in which the mood can fluctuate considerably when populated by short wirey horsemen??
for ales fermented at 17-19 i bring them up to 21-22 to finish, as arcane says, to drive attenuation. this works well

rhinofarts said:

ArcaneXor, after 3 days at 18C, what would you bring the temp up to then?

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I usually set my temperature controller to 22C for another two days, and let it free rise up to room temperature after that, which for me is about 26C.

rhinofarts said:

Before this I been using a heating belt and my temps were up and down like a jockey's balls.

Will this definatly impove my beer. I am no expert but it seems already to be a much more controlled balanced fermentation.

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I actually did the LOL thing at the jockey comment. I never heard that expression before, and now I have a new phrase to share with random people. Usually my kids get the bulk of my sophomoric humor. They've both perfected the "eye roll" but they do laugh.

I keep my temperatures stable throughout their time in the fermenter, bringing them up just a couple of degrees at the end of fermentation. I like to ferment at the low-mid range of the yeast strains' fermentation temperatures and then finish it at the mid-upper range at the very end.

Yooper said:

I keep my temperatures stable throughout their time in the fermenter, bringing them up just a couple of degrees at the end of fermentation. I like to ferment at the low-mid range of the yeast strains' fermentation temperatures and then finish it at the mid-upper range at the very end.

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Why is this??

I would add that fermentation is all about happy healthy yeast. You're goal is not to stress them. Higher temps don't really stress them, they like warmer temps, but if the yeast fluctuate in temperature they will become stressed. Stress causes all kinds of effects that are not desirable. On the flip side, higher temps can add to fusel alcohol and ester production.

grndslm said:

Why is this??

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I like a "cleaner" yeast flavor in many beers, unless they are supposed to have a certain yeast character like in Belgian beers or some English beers. I dislike fruity flavors (esters) in American pale ales, for example, and will ferment at the lower range of the yeast strain's optimum range. I raise the temperature slightly at the tail end, just to make sure the yeast don't get lazy and fully attenuate.

OK, Thanks for the replies. I have left it for 3 days at 18C, and now today I have increased it to 22C, there is no fear of room temps bringing it up higher, as it's always cold in Ireland. Will I let her ferment away at 22C now? I want to get my temp control sorted, to rid my beers of s**ty flavours. Thanks!