The_Canmancan

Recipes 

What are the implications of my ale fermentation temperatures varying up and down in a yo-yo pattern?

My house is poorly insulated, and when the heat comes on the thermometers on my carboys varies between 64 and 72. Of course, this doesn't happen right away, but over a period of several days, in a yo-yo pattern.

AmandaK

Recipes 

The yeast will likely become confused and may go dormant when it goes from 72 to 64. They may wake up again when it swings back up to 72. You'll also have issues with ester formation depending on the timeframe of these yo-yo patterns.

Do you have a sleeping bag or other insulating material to help cushion the swings? Or even a closet near the inside of your home?

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On deck: Dopplebock, Pliny, Munich Helles, Big Brew Day CAP
Fermenting: #69 Nelson Saison, #72 3711 Cider Two, #76 West Coast Bitter
Souring: #32 Lambic 2.0, #49 Lambic 3.0, #60 3763 Flanders Brown, #61 WLP665 Flanders Brown
Conditioning: #38 Golden Sour, #58 Hooch Cider, #67 Schwarzbier, #70 3711 Cider, #71 Kolsch
Drinkin': #16 Lambic 1.0 (Drunk Monk BOS), #52 Rye Saison, #56 Saison-Brett, #57 BGSA, GUEUZE!, #65 Maibock

300RUM

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It depends.

If it starts cooler and warms over a couple days you probably ok. If it starts hotter and cools then warms within each day you will probably have esters, fusel and other off flavor then when it cools again yeast will flocculate and maybe no attenuate fully.
imo fermentation temp. control is the most important step in brewing.

Yooper

Recipes 

Even if you don't insulate with a sleeping bag, something that could work very well for you is to submerge your fermenter in a water bath in a cooler or bin. It takes a LONG time for 5 gallons of beer and 5-7 gallons of water to change temperature, so that would really help minimize temperature fluctuations.

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WoodlandBrew

Recipes 

I can't find the article that I read on this, but temperature fluctuation will stress the yeast and it may cause off flavors. Your beer would be able to tolerate the temperature change better if it was in a bucket of water.

This blog post describes the effects of a large water bath on changing temperature:
http://woodlandbrew.blogspot.com/2012/11/lagering-outside.html

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Woodland Brewing Company Brewing science for those of us without a Ph.D
BLOG: Brewing Boiled Down and learn more on The WBC You Tube Channel Ready to drink: Champagne Cider, 50c 28c and 19c Ale, Adventinus clone. Up next: Douppleweizenbock, Eisbock, Saision Terri, Raspberry Cream Ale

tre9er

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Just do this ^

Get a rubbermaid for cheap from Big Lots or WalMart and fill it halfway with water.

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AmandaK

Recipes 

Very good idea.

__________________
BJCP Certified Beer Judge
On deck: Dopplebock, Pliny, Munich Helles, Big Brew Day CAP
Fermenting: #69 Nelson Saison, #72 3711 Cider Two, #76 West Coast Bitter
Souring: #32 Lambic 2.0, #49 Lambic 3.0, #60 3763 Flanders Brown, #61 WLP665 Flanders Brown
Conditioning: #38 Golden Sour, #58 Hooch Cider, #67 Schwarzbier, #70 3711 Cider, #71 Kolsch
Drinkin': #16 Lambic 1.0 (Drunk Monk BOS), #52 Rye Saison, #56 Saison-Brett, #57 BGSA, GUEUZE!, #65 Maibock

WoodlandBrew

Recipes 

sure, Yooper gets to the submit button 5 minutes before me and gets all the credit. :-P

__________________
Woodland Brewing Company Brewing science for those of us without a Ph.D
BLOG: Brewing Boiled Down and learn more on The WBC You Tube Channel Ready to drink: Champagne Cider, 50c 28c and 19c Ale, Adventinus clone. Up next: Douppleweizenbock, Eisbock, Saision Terri, Raspberry Cream Ale

AmandaK

Recipes 

Okay, you're special too! And you get one star!

Looking back on the thread though, it's so much easier to see posts by people with bolded names/avatars. Maybe that's just me though.

__________________
BJCP Certified Beer Judge
On deck: Dopplebock, Pliny, Munich Helles, Big Brew Day CAP
Fermenting: #69 Nelson Saison, #72 3711 Cider Two, #76 West Coast Bitter
Souring: #32 Lambic 2.0, #49 Lambic 3.0, #60 3763 Flanders Brown, #61 WLP665 Flanders Brown
Conditioning: #38 Golden Sour, #58 Hooch Cider, #67 Schwarzbier, #70 3711 Cider, #71 Kolsch
Drinkin': #16 Lambic 1.0 (Drunk Monk BOS), #52 Rye Saison, #56 Saison-Brett, #57 BGSA, GUEUZE!, #65 Maibock

tre9er

Recipes 

Hint, Hint! *coughbecomeapremiumsupportercough*

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Skal!
Den Faaborg Bryggeri