Increase temp at the end of primary?

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telemaster

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Hello,
Well, I'm going on week 4 in primary of my inaugural brew. I haven't peaked or touched it besides some gentle rocking from time to time.

This weekend I am planning to check the gravity, and if all is well, rack to a secondary for a week and add some gelatin.

It has been fermenting (US-05) in my basement at the lower end of the temperature range. Probably 58-62; I have seen the thermometer (ambient temperature) at 59 in the morning and just above 60 in the evening.

Now to my question. I have read that some people bring their primary to room temperature for the final few days of fermentation to make sure the yeast clean up as best they can. Should I do this? What are the benefits/risks? Or, is this another plastic vs glass and aluminum vs stainless question?

Thank you much! :mug:
 

dontman

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That is some pretty cold fermenting temps. You might have a slight diacetyl problem. You should be due for a gravity reading. When you take it, taste the sample and if you detect any butter taste or oily slickness in the mouthfeel then, yes, I would recommend you bring the temp up to 70-72 for 48 hours prior to secondary. Otherwise don't worry about it.
 

ArcaneXor

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Bringing up the temperature late during fermentation creates conditions that make the yeast less likely to flocculate prematurely, increasing the odds of full attenuation while decreasing the odds for off-flavors due to diacetyl and other fermentation by-products.

Something to keep in mind is that fermentation is an exothermic process, i.e. the temperatures in the beer during peak fermentation are significantly higher than ambient temperatures. As fermentation winds down, the beer cools even if ambient temperatures don't change. This cooling, in addition to the increasing ethanol toxicity, can cause yeast to switch to survival mode. By bringing up the ambient temperature, you counteract the cooling due to the loss of exothermic heat generation and increase yeast metabolism.

Many micro-organisms roughly double their metabolic rate with each 10 deg C temperature increment within the range of thermal tolerance. I expect yeast behaves similarly.

Edit: After four weeks, don't worry about it. You want to start raising the temps once fermentation is about 75-80% complete - usually after 4-5 days or so, depending on the style.
 

cuinrearview

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After four weeks I don't think you'll have any problems with dicetyl. A dicetyl rest is usually only used for lagers which ferment at a lower temp than what you are. I'll raise the temp in primary for an ale only to finish out a very high ABV beer. I also don't think that you'll need any finings to clear this beer up. You shouldn't need a secondary as well unless you plan to dry hop or it's a bigger (more than 8%) beer. If your hydro reading is what you expect it should be more than ready to bottle depending on what you're making. Kudos on your patience with your first brew!
 
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telemaster

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First, thanks for the comments/suggestions :mug:

It has been very difficult to wait so long and not mess with the beer, but as a very good friend once told me, "You cannot rush a good thing" and beer is a very good thing! :D

It's a True Brew Red Ale kit with steeping grains. Expected ABV is somewhere around 5%

So what I'm hearing is that after four weeks it wont make much of a difference, but the only thing it could do would be to decrease the diacetyl level and other off-flavors (but most likely it's too late for this anyway).

What to do... what to do...

I think I'll go ahead and move the fermenter upstairs to a ~70F environment for two days and see what happens... maybe nothing and maybe something.

For bottle carbing: Will it be OK in the basement at the lower temps (~60F)? I assume it will just take a little longer to carbonate... is this a correct assumption?
 

dontman

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You've already been very patient but by putting those primed bottles in that cold basement you could be doubling the time it takes to carb. I've had cold beers take 5-6 weeks to carb up. I'm talking <60. This time of year I keep the cases in my kitchen for the carbing period and then move them into the cellar for storage.

If you can clear out an unobtrusive corner in a 70 degree room they will be nice and ready for you in three weeks.
 
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