I had a session in which my boiloff rate was just way wrong (I'm still learning my kettle).
I typically calculate my gravity during the boil to see if it is approaching my target. I grab a sample, cool it to under 80 degrees, read temp and gravity, and correct it to 60 degrees.
I do this because measuring water volume is nigh on impossible (and wrong anyway) in mid-boil. So if all is going as planned, my OG should peg my calcs at the end of the boil. This thread is about what to do when the gravities are coming in too low.
In my session, I began noticing that my gravities were too low about halfway into the boil. I decided that I'd need to add sugars in order to achieve my target OG of around 1.072 (IPA).
I got to the end of the boil, shut down and left it hot. I added extract until my corrected gravity was at target, then I cooled, transferred to fermenter and pitched.
Now I know the typical scenario is to boil too little volume and then add water to thin it down. But in my case I had to raise OG.
The other option would have been to boil longer but then I would have ended up with high IBUs.
Anyone else run into this situation? I'll stipulate that I need to learn my boiloff rate but frankly I thought I did know it. I ended up with 5.8 gals when I thought I'd end up with 5 based on previous experience. :shrug: I even kickd up the heat when I saw the gravities were on the low side.