Adding water during fermentation

This may seem like an odd question, but has anyone ever added water to a fermentor during primary fermetation? Here is the back story…I brewed my first 10 gallon batch this weekend (my 4th AG batch overall). It was a double recipe of Caribu Slobber. I used the BeerSmith software to get my water volumes, and planned to use two 6 gal glass fermentors. All in all, everthing went smoothly, except that I came up a little short on my volumes. I have 5 gallons in each fermentor, but I was looking to have 5 gallons for kegging. My gravity came in at 1.060 which is 6 points higher than the BeerSmith print out. I did not realize that my volume was low at that point and pitched the yeast. If you do the math, another gallon of water will put the gravity at 1.054. I would like to boil and cool a gallon of water and add a half gollon to each fermentor. Any thoughts? If there is any concern, I don’t have a problem just leaivng it as is. Ideally I would like to have a little more beer than a little stronger beer. This is my second time brewing Caribou Slobber and I really liked the first batch. Maybe I’ll add a half gallon of water to one and leave the other alone.

I wouldn’t. I’d just leave it be and live with a little less, but stronger beer.

As I am a “noob” to brewing, I will take your advise and leave it. Any specific concerns? Contamination, fermentation temperature fluctuation???

Your newly added water won’t be mixed with the rest of your wort properly. Wort is denser than water so a lot of the water may stay towards the top of your fermentor. I would think the natural movements of fermentation may help mix the water, but why risk a problem? Also yeah, if you’re water is cold it could drop your wort temp and put the yeast to sleep. If it’s too warm, your wort would warm up which may cause the yeast to produce unwanted biproducts. There’s also chance of contamination… it’s just not worth the risk considering you have what… 9gallons of wort fermenting… and you want to get up to 10? Big deal. Live with 9 gallons and go brew another beer!
:cheers: