Fermentation Temps

pduppel · November 9, 2011, 2:52am

I know I am probably inviting trouble here, but what are the thoughts on ale fermentation temps?

Clearly, the yeast producers list the temperature ranges on the packaging, but I have read a few posts about fermentation in the 60-65 range producing clearer, cleaner tasting beers.

I’m thinking about it because I have had ‘issues’ with perceived astringency in a couple of my darker beers. My first reaction was to reduce % chocolate malt, when used. But I have still noticed this ‘flavor’ in a couple other beers.

The other option I have considered is that I have a high sulfate to chloride balance in my water and I will check this with my next batch.

So, that brings me to my final suspect (for now). I have always tried to target the upper end of temp level (70-72F) to get the best attenuation.

If I move to 60-65F, can I still expect full attenuation AND cleaner, clearer beer?

waszup · November 9, 2011, 3:16am

There’s two different topics here.

An unbalanced Ph can get you into trouble with atringency. I use the Br’un water spread sheet and pay close atention to my Ph value. You’ll need a water report for Ward labs (W-6 report I think??) and you’ll need to input your grains used. Then your PH on the spread sheet should be around 5.2 to 5.5. You may have to add some salts to alter your water. Others use ezwater spread sheet, it’s clearly simpler to use and many swear by it.

From what I’ve read on this forum the amount of yeast pitched when you begin fermentation, your mashing methods, grains used, temperature, and other things determine your attenuation outcome. All i can say it if you don’t use a starter for your yeast you should and mash below 150F to get more fermentable sugars.

pduppel · November 9, 2011, 3:40am

Thanks, I think I threw a little too much info into that initial question. Let me boil it down a bit: given the same mash profile, can I still expect to get similar (~+/-5%) attenuation while fermenting in 60-65F range, as compared to 70-72F range?

shadetree · November 9, 2011, 5:14am

As long as you’re in the operating temp range and you pitch enough healthy yeast and don’t suddenly drop the temp from say 72F to 60F, the fermentation temp has little to do with the attenuation. Fermenting most ale yeast in the 64-68F range (beer temp, not ambient) results in solid, clean fermentations. You can speed up the process by raising the temp towards the end, but the FG will be the same.

abrown001 · November 9, 2011, 1:51pm

Although it may seem counterintuitive, you should get the same attenuation, even at cooler temperatures. Also, common wisdom suggests that the temperature ranges on the manufacturer’s packages are for yeast propagation; so the upper end of the range will ferment, but it usually won’t produce the best beers. For the most part, I stay in the bottom half of the range for the first 70% of fermentation.

pduppel · November 9, 2011, 3:26pm

Awesome, thanks for the input guys.

fimbrew · November 11, 2011, 1:57pm

Yes you should get the same attenuation but it will take longer. You could always rouse the yeast to help it along. Cooler fermentation creates less esters and fusels so you will get less character from the yeast.

As for the astringency it could be from the grain or hops. You may need to acidify your sparge water.

pduppel · November 11, 2011, 5:52pm

Fimbrew, I have generally been opposed to treating my sparge water, but for $2.99 and 30 seconds of my time, I would be stupid to not eliminate one more possible source for off-flavors. So, I will be giving it a go on the next batch.

shadetree · November 11, 2011, 6:09pm

Only if you’re fly-sparging. If batch-sparging, unless you have extremely high pH water, you don’t have to worry about the sparge pH. Are you checking pH during the mash?

pduppel · November 11, 2011, 7:16pm

I do fly sparge and, in previous batches, I have not measured mash pH. I basically take BruNWater output and trust that it will get me to where I need to be (I know, I should confirm, but I am not sure that I would alter my plan based on a colorPhast strip result, given some criticism I’ve read. And I’m not prepared to invest in a pH meter yet). For mash acidification, I try to stick to dark malt adjustments only in darker beers, but will be tweaking with calcium chloride and gypsum on my next batch since it’s too light to adjust with dark malts.