I’m not alone in noting that, especially in summer, the first recent pour of homebrew tends to be foamy at first. Part of the problem is that the beer in the draft tower cools down so that the CO2 in it becomes less soluble and tends to come out immediately. Today I set up a fan to blow cool air into the draft tower to try keep the beer in the draft tower cooler.
I used a fan from a dead old Mac Mini and a 5V power supply from a Ye Olde Palm Treo, soldering a 2.1mm barrel plug and socket to make it dis-connectable.
The fan is rated for 12V and the power supply is 5.2V. I tried a higher voltage power supply and it did blow a lot more air, but subjectively the fan blew hard enough on the lower voltage supply, and it was definitely quieter.
I was able to run the power cord out through the drain port at the bottom of the fridge as seen here.
Here’s another shot of the installed fan with both kegs in the fridge.
I used safety wire hold it in place.
Since my last review of the BeerBug hydrometer I’ve had a chance to do some more testing. At first the data was pretty poor. I sent those results to the BeerBug folks who thought it might be because the device wasn’t level. It seems pretty sensitive to this, as it couldn’t have been more than few degrees off.
I got a stick-on bubble level like this one, re-tared, and left it for a couple of days in some santizer solution (approximately SG 1.00 and with the taring should read 1.000 regardless). The results were much better than I’d seen before:
There is still a little drift that seems to be temperature related. The indicated specific gravity varied from about 0.999 to 1.007. Probably because I tared at a time when the temperature was relatively low, the drift is mostly at the upper end. It would be better to tare at the average fermentation temperature.
As usual, I have a batch of beer just coming out of primary so it will be a while before I can test it under actual conditions, but I think if it the device is kept level it will work well enough to ascertain the end of primary fermentation.