Can too much boil off affect gravity?

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scoundrel

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Hi All,

I have a large pot and I can fit it over two of my stove burners. This helps to get to a boil quick. Usually I back off on one burner during the boil, but last night I left both on high. It was an extract boil of 2.5 gal with 7 pounds of DME. When the boil was over a significant amount (at least 1.25 gal possibly more) of volume was lost. I was expecting a gravity around 1.056 and it ended up around 1.036. I couldn't believe it. Can too much boil off cause this?

Thanks!!!
 
As you boil off water, the SG will get higher. If you use a rapid boil, you boil off more water per unit time than a slow boil. So, this is backward from what you found.
 
Ok good. That the response I was hoping for. Which leads to my next question. Is it possible that the DME I used had a PPG significantly lower than 44? I bought my DME online from a supplier who posts on this site. I won't mention names since there's no need for excess drama, but it was obviously repackaged, probably from a 50lb bag.
 
Do you mean they cut the DME with something else?

Did you weigh the bag?
 
Do you mean they cut the DME with something else?

Did you weigh the bag?

I have no idea and I definitely don't want to throw around accusations without out being 100% sure, but this is the first time I ordered DME through them. I'm not even sure what you could cut it with, lol.

I did weigh the bags and the two 3lb bags came in at 3.04lbs and the one pound was 1.02lbs. I just can't figure it out. I've brewed 100 gallons over the last year and have never run into something like this.
 
What was your total water volume when you took your OG? We can use that to backtrack how much DME you put in there.
 
Exacly, about the only way you're going to miss your gravity reading when brewing extract is if you top up with additional water and don't mix thoroughly.
 
The total was 5.125 after pitching my starter. I have a line on my better bottle. I checked the gravity roughly 5-10 times (in amazement) after pitching and aerating and verifying the gravity temp at 67 degrees. Then I tested my hydrometer with 68 degree water and it was pretty close to spot on 1.000.

I ultimately solved it by whipping up 2lbs of another dme in a quick 10 minute boil and about a 1/3-1/2 gallons of water, quickly cooled it and added it. It pulled the gravity up to 1.062. So we'll see. It would have been my first 1.036 IPA otherwise.
 
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