At the last Square Kegs meeting, I was talking to some of the other club members about the hack we use to monitor fermentation progress without constantly pulling gravity samples out (or off of) our fermentors. Since it didn't seem like the majority of the club did this or had heard of it, it seems post-worthy.
I can take no credit for this idea. For the sake of argument, I'll just assume that Jeremy stumbled upon this on his own. (I'm sure that someone else out there did this first, but I like giving him the credit.)
Typically I'll take gravity readings throughout our brew day in order to make sure we're on target for our numbers and to determine if we need to adjust up or down towards the end of the boil. Typically I'll pull an O.G. (original gravity) reading during cooling. Then, once fermentation visibly starts, I'll use a wine thief to fill a sanitized sample jar and drop a hydrometer in it. We'll then leave the sample jar full of fermenting wort in our fermentation freezer and use it for gravity readings. Depending on the beer, it can be a little tough to read the hydrometer through the yeast and other trub that accumulates in the sample jar, but it's easy enough to get an approximate reading.
I also realize that technically the volume of wort in a fermentor is going to be a couple of degrees warmer in the middle of the fermentor and that there will be a difference in pressure between the two. However, I think that the reduced risk of infection and the ability to adjust fermentation temperature or dry hop at the appropriate time totally outweighs whatever differences those factors introduce.
