I brewed up something on the weekend, and was expecting 1.054 and got 1.044. Normally I get close, or more than what I expect with my methods. Only thing I noticed to be different this time around, was my mash temp was a little lower than normal, 148F down to 142F in the hour mash, compared to normal 154 or so down to 146 or so. Thoughts why my og was so much lower?
Original gravity and mash temp
- Thread starter Cammyg
- Start date
Help Support Homebrew Talk:
Cool temperatures like that will indeed affect your efficiency a bit. However the main thing to consider is always the crush and the volume. Did you nail the volume that you intended, or is it higher than you expected? If you nailed it, then how did you crush the grains? Did you do it yourself or did you have a homebrew shop crush them for you? Shops are notorious for not crushing the grains very well. It's better if you can set the mill yourself to ensure a good crush every time. If you can't do that, then consider a double-crush from now on and watch your efficiency jump 10 points overnight.
Oh okay awesome thanks for the info. Volume of water eh, is there a way to be calculating this? I had used 3.5 gal in my mash of 10lb grains then another 3.5 gal in my sparge water. I just let the grains sit for an hour in the insulated mash pot, then take them out and put them into another pot with another 3.5 gal at 168F and stir them around in there for 15 minutes then combine the 2 for the boil
It is what volume that you start the boil with and what you end up with into the fermenter. If you usually get 7 gallons for preboil and this time get 8 your OG will be lower. If the recipe is for 5 gallons into the fermenter and you end up with six your OG will be lower.
I mash with about 1.25 quarts per pound of grain. The the calculations stop and measurements take over. I measure the first runnings. Then I divide what I need to get my preboil amount roughly in half, do the first sparge, measure the volume again, then do a second sparge with what I need to get to my preboil amount.
I mash with about 1.25 quarts per pound of grain. The the calculations stop and measurements take over. I measure the first runnings. Then I divide what I need to get my preboil amount roughly in half, do the first sparge, measure the volume again, then do a second sparge with what I need to get to my preboil amount.
The grains permanently soak up 0.1 gallons per pound, so for 10 pounds that's 1 gallon of wort lost forever. So if you used 3.5 * 2 = 7 gallons water then you should have ended up with 6 gallons immediately prior to the boil, a.k.a. "preboil volume". Then assuming you probably boiled off about 1 gallon during an hour-long boil, you'd end up with a 5-gallon recipe. This is just fine if you intended to have 6 gallons of wort before the boil and 5 gallons after. But... if you intended to have 6 & 5 but instead ended up with let's say 6 gallons initially but only boiled off a half gallon to 5.5 gallons due to a weak boil or whatever, then your measurements for gravity will be low by a factor of 5/5.5 = 91% as much as you expected. So then if you wanted an initial gravity of 1.054 at 5 gallons but instead had 5.5 gallons then you should expect gravity to be 54*.91=49 points or 1.049 instead of 1.054. As such, depending on accuracy of your volumes, your gravity could be low based on that.
However since you got even lower than that, it appears that something else might also be happening like less than adequate crushing of the grains or improper mash pH. Or it could be a combination of some or all of these factors.
![Craft A Brew - Safale S-04 Dry Yeast - Fermentis - English Ale Dry Yeast - For English and American Ales and Hard Apple Ciders - Ingredients for Home Brewing - Beer Making Supplies - [1 Pack]](https://m.media-amazon.com/images/I/41fVGNh6JfL._SL500_.jpg)
