Author Topic: Pre-Boil Gravity vs Original Gravity  (Read 8301 times)

Offline stevep

  • BeerSmith Apprentice Brewer
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Pre-Boil Gravity vs Original Gravity
« on: February 06, 2011, 11:23:31 AM »
On the Brewing steps print out, under the mash out steps it shows a Pre-Boil Gravity of 1.043. After the section for adding the yeast it shows a Measured Original Gravity Estimate of 1.051.
Why the difference? I hit 1.043 pre-boil, but if anything it went down to 1.042 after boil. I'm not quit understanding this.
Thanks
Steve

Offline Hopback

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Re: Pre-Boil Gravity vs Original Gravity
« Reply #1 on: February 06, 2011, 12:40:19 PM »
Boiling should concentrate the wort even more because of the water that boiled off. There's no way the gravity should go down from the pre-boil to the post-boil unless you added water to the boil pot AFTER you took the pre-boil reading and then didn't quite boil off all of the addition. Some homebrewers do like to add the amount of water they expect to boil off to the boil pot thereby maintaining the same gravity for pre-boil as post-boil. Based on the recipe numbers you posted, I don't think adding any additional water to the boil pot was specified in the recipe. Did you add additional water to the boil pot?

Offline stevep

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Re: Pre-Boil Gravity vs Original Gravity
« Reply #2 on: February 06, 2011, 03:51:38 PM »
Thanks for the response Hopback,
I didn't add any water to the pot. I measures gravity at 150 degrees and it was 1.024 which plugging that into BeerSmith would be 1.043 at 60 degrees.
Maybe my thermometer is not reading accurately and that is why I'm showing these numbers. I'm using the one that came with the turkey fryer so I am looking into a better one.
Thanks again
Steve

 

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