Fermentation Temp

So I have read in several places that beer will actually warm up during fermentation... I guess my question is how much... I just bought a probe thermometer that seemed to work great during boil to take boil temps... The package stated the range of the thermometer was from 50F to 450F... the highest I had the boil was 215F... Today is the first day of fermentation and I had fed the probe down into the primary when I sealed it on brewday.. Just looked at the temp and it is reading 93F... Is this a normal range or does it appear the thermometer isnt working? The room I have the primary fermenting in is 64F that is what makes me wonder this is only my 3rd beer and this seems like the fermentation temp is way too high for the room temp to be at 64

First problem is that it is boiling at 215, I've never had a wort boil higher than 212. So, unless you are boiling under pressure I would consider that a faulty piece of equipment. Next, if you are fermenting at 93 that beer is going to have some problems. If the ambient temperature is 64 I wouldn't expect the fermentation to raise it much past 70 if you are otherwise doing nothing to keep the fermentation temp down. You might consider getting one of those black strip thermometers that stick to the outside of your carboy, in my experience they are surprisingly accurate and always in line with my Ranco's.

Thanks for the quick reply.. I should have made sure the thermometer was calibrated in some ice water first to make sure it was accurate.. I do have a strip thermometer on the side of my primary but I can never easily read it so I thought I would attempt to upgrade... Looking at that the 66F mark does look colored and the 68F mark has some color to it so it appears the actual fermentation temp is between 66F and 68F

Bensiff said:

First problem is that it is boiling at 215, I've never had a wort boil higher than 212. So, unless you are boiling under pressure I would consider that a faulty piece of equipment. Next, if you are fermenting at 93 that beer is going to have some problems. If the ambient temperature is 64 I wouldn't expect the fermentation to raise it much past 70 if you are otherwise doing nothing to keep the fermentation temp down. You might consider getting one of those black strip thermometers that stick to the outside of your carboy, in my experience they are surprisingly accurate and always in line with my Ranco's.

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With the sugar in the wort it is possible for the boil to be above 212F.

Sounds like you are good to go then. Also calibrate the top end of the thermometer in boiling water. One of your best friends in brewing will be high quality instruments. Relying on cheap thermometers, pH meters, scales and the like will cause problems. I have some cheaper stuff, such as a cheap made in China sold on eBay gram scale, but I know its accurate as I have a high end reloading scale and high precision calibration weights I can use to gurantee its accuracy. Its also a good idea to have backups if you need them, I can always double check my Ranco digital thermometers if their probe gets messed up.