Temperature of Water

I'm fermenting in an old Igloo Cube (I remade a new lid).
Yet I'm not sure what temperature to keep the water.
It's at about 62 right now. I know that the temperature
of the future beer can be fermenting 8-10 degrees above
the actual water soooooooooooo... Does this mean that
62 degree water on the inside should keep the beer on
the inside near 70 degrees?

Just need some reassurance and NO FUSELS!!!

I'm no chemist, but I believe your water temperature will closely match the temperature of the beer. It's true that ambient air temperature is not the same as the fermenting beer, but because liquid insulates it and the temperature will be very similar. It will also save the beer from temperature fluctuations, since it will take a looooong time for 5 gallons of beer and, say, 3 gallons of water, to change temperature.

Thanks for the info Yooper Chick.

(AND thanks for the pix of your cooler lid. Copying is the sincerest form of flattery.)

Mr. B:

I assume you are fermenting in some sort of fermenter inside the Igloo cube, so you have the fermenter in a water bath in the Igloo. If the fermenter is a glass carboy, and your water bath termperature is fairly stable, then you beer temperature will be very close to you water temperature. This is due to the fact that the glass is a good heat conductor, and you have good thermal contact between the beer and the water via the glass carboy. During the primary (active) phase of fermentation, when the yeast is generating maximum heat, the fermenting wort is being well stirred by the CO2 off-gassing so you have efficient heat transfer to the cooling water, and you have convection currents in the wort as well as the wort at the carboy surface is cooled, becomes denser than the warm wort and sinks to the bottom of the carboy. During the secondary (slow)fermentation phase, little heat is generated so the temperature of the beer is the same as the cooling water.

The more water you have in the igloo, the better you can manage the fermenting wort temperature due to more thermal contact and more water to absorb the heat of fermentation. If you are using a plastic fermenter, you will have a bit less thermal conductance between the wort and water due to plastics being better insulators than glass, but your wort temp probably won't be much different higher despite this in the primary fermentation phase.

And for the little that it's worth, I am a chemist, but a physicist or chem engineer would give you a better answer with lots of cool math that I could never understand...but the basic answer is the same.

Thanks for the thorough, yet simple response AiredAle.
I am an English teacher so if ya gave me all of the fancy
mach equations I would have little clue on how to follow
them.

I use the stick-on thermometers on carboys and buckets. I try to get the wort to the desired temperature before pitching the yeast. The wort and water will not change temperatures quickly because of their mass. Just adjust the temperature in the water bath with ice bottles to maintain the desired wort temperature.
http://www.breworganic.com/browseproducts/Fermometer-Stick-On-Thermometer.html

Me too, but if the stick on thermometer gets wet, it's ruined. I just float a floating thermometer in the ice water bath and check the temp whenever I need to.

Yooper Chick said:

Me too, but if the stick on thermometer gets wet, it's ruined. I just float a floating thermometer in the ice water bath and check the temp whenever I need to.

Click to expand...

I have submerged the stick-on thermometers - didn't seem to hurt them. They are hard to read underwater, though, so I try to keep them above the waterline.

I try to keep the wort at the desired temperature - usually the water bath is colder during fermentation. After fermentation has subsided, everything comes to the same temperature in a day or two.

Thanks for all of the great advice.
What would you All say is the "desired" temperature?

Well, it depends on what you're making! The ideal range of your yeast is where you want to be. I usually ferment at the bottom of that range, and I'm happy with my ales and lagers.

mrb said:

Thanks for all of the great advice.
What would you All say is the "desired" temperature?

Click to expand...

From the Wyeast website:

YEAST STRAIN: 1272 | American Ale II™

With many of the best qualities that brewers look for when brewing American styles of beer, this strain’s performance is consistent and it makes great beer. Fruitier and more flocculent than Wyeast 1056 American Ale yeast, slightly nutty, soft, clean with a slightly tart finish. Ferment at warmer temperatures to accentuate hop character with intense fruitiness, or ferment cool for clean, light citrus character. Expect good attenuation, but this will vary with grist makeup, mashing protocol, or other wort characteristics. Reliably flocculent, producing bright beer without filtration.

Origin:
Flocculation: High
Attenuation: 72-76%
Temperature Range: 60-72F, 15-22C
Alcohol Tolerance: 10% ABV

With this yeast, I cool the wort to 60 to 62 deg. F. before pitching yeast. Keep the temp there until fermentation starts to slow down (1 to 3 days, usually). Then let the wort warm up slowly to the upper end of the range - 68 to 70 deg. F. Letting the wort get warmer as the fermentation subsides helps to ensure that the yeast finishes the fermentation.