Temperature Question

I have a Temperature question on my first batch. I live in Florida and I bought a small fridge to use as a fermenter in my garage because of the Florida heat. I am going to order an external thermostat for the fridge but I have not done so yet.

I brewed my first batch yesterday and of course made my first mistake when I pitched the yeast at around 93 degrees. I stuck the beer in the fridge to ferment and ran the fridge for about an hour to keep cooling the beer but I turned it off when the fridge got down to around 50 degrees. Not sure what the temp of the beer was.

The fridge is in my garage and the outside temp got into the 50's last night. I was concerned that it got too cold but when checked the fridge around noon the thermometer I had stuck in a glass of water was reading around 75 degrees. I had fermentation bubbles last night and earlier today.

Tonight the temp is getting down to the mid forties and I am not sure what to do. It seems that the temp from the fermenation is heating up the smaller space in the inside of the fridge. But I am concerned if I leave the door open it will get too cold.

Any suggestions?

40s is a bit cold and I wouldn't move mine outside in Montana (20s at night) but if fermentation has taken off then i wouldn't be too concerned with 40-50s just for a few hours at night.. Wrap a sleeping bag around it and you'll be ok :rockin:

Thanks. The first night it dropped the termperature down to 65 and held steady all day. Last night it was not as cold and dropped the temp down to 63. It is warming up to about 70 today so i think I am good.

The wort is a very large thermal mass that will temper the temp swings. An insulated frige will further temper the external temps. During active fermentation the yeast will throw off heat that will increase the wort temp. The purpose of the ferm chamber is to maintain the wort within the optimal temp to produce tasty beer. The yeast can and do live and thrive at both higher and lower temps. However, outside the published range for your yeast they will produce undesirable flavors. If you add a brew belt and a temp controller you will be better able to keep the yeast within the optimal temps irregardless of the ambient temp.

Presume bringing it in the house isn't an option...assuming the temps are a bit warmer and more stable in there?

If you're doing ales just buy a rope tub and some ice, keeps me at 70 or under.

WilliamShakesBeer is right on.

Due to the thermal mass of the wort and the insulation of the fridge, the wort temp isn't going to change hardly at all in a 8-12 hour period, even if it's 40F or 100F outside.

Get a temp controller and keep it set at the appropriate temp and the temp outside the fridge won't matter. Also make sure in the future that you cool down and pitch at or slightly BELOW your intended fermentation temp.

Good luck!!

As you suggested the insulation from the fridge and heat from the wort kept it in the proper range despite the cold. Temps are now up so I am good. I just hope the higher temps from the pitch and the first day in the mid to upper 70's didn't mess it up too much.

Thanks for the replies and advice.

Some ale yeasts are a bit more picky about temperature than others. My fermentation temps usually range from high 60's to mid 70's. You might notice some characteristics accented with higher temps (for example, WL California tends to be a little more fruity at higher ferment temps). But I would suggest that if you can keep it below the mid-70's you will be fine from a fermentation standpoint and any variations from temperature are going to be pretty subtle.

Cheers!

+1 on what "sivdrinks" said. In both summer and winter, mine is inside in a rope tub that you get at walmart for about $6-7. In the summer, I add saved personal size drink bottles filled with tapwater and frozen. Add one in AM and one in PM and keep alternating for the first four or five days.. at least. Cheap, doesn't require skills or much added space. I keep the water level in the bucket just below the stick-on thermometer so I don't get it wet. The personal drink bottles are a good size.. but, liter ones don't fit well. I also use the quart bottles that apple juice comes in.. the rectangular ones.. not round.. as they fit and have a larger ice capacity. Another alternative is to use the 1 gallon zip lock bags filled with water and frozen. Lay them flat in the freezer and they are easy to pack in the rope bucket. lots of alternatives.

agreed with the swap cooler, rope tub, water bath ideas. The water effectively increases the thermal mass. By simply doubling it to 10 gallons, even without insulation, the temperature swing of the beer will be half that of the ambient air over a 24 hour period.
See this blog post for details:
http://woodlandbrew.blogspot.com/2012/09/swamp-cooler.html

detailed analysis of ambient temperature effects on fermentation temperature to come on the same blog 11/3