Author Topic: Adjusting estimated original gravity  (Read 1278 times)

Offline enkamania

  • BeerSmith Master Brewer
  • ****
  • Posts: 53
Adjusting estimated original gravity
« on: December 08, 2020, 02:26:06 PM »
Greetings,

I've switched to a less vigorous boil and now my OG is coming out lower than predicted.  How do I lower the estimated original gravity?

P.S.  I thought I asked this before, but couldn't find the post.

Offline BOB357

  • BeerSmith Grandmaster Brewer
  • *****
  • Posts: 681
  • Beer is my bucket list!
Re: Adjusting estimated original gravity
« Reply #1 on: December 08, 2020, 02:54:18 PM »
When you lower boil vigor the boiloff is reduced, leaving you with a larger volume and lower OG due to the added dilution. Adjusting the boil off in your equipment profile is the proper way to bring your estimated gravity back in line with your process. BeerSmith relies on your inputs in order to properly calculate gravity, bitterness, volumes, color and various other estimated values. Any time you make a change in your process, you need to reflect it in one of the profiles you're using.
Bob

Offline enkamania

  • BeerSmith Master Brewer
  • ****
  • Posts: 53
Re: Adjusting estimated original gravity
« Reply #2 on: December 08, 2020, 04:22:57 PM »
I get the volumes to match, but the gravity doesn't budge when I change the boil off rate.  The problem for me is I have a mash efficiency of 75 and a brewhouse efficiency of 70.  So either my mash gravity is predicted wrong or my OG is wrong.

Offline BOB357

  • BeerSmith Grandmaster Brewer
  • *****
  • Posts: 681
  • Beer is my bucket list!
Re: Adjusting estimated original gravity
« Reply #3 on: December 08, 2020, 05:14:19 PM »
You need to understand the difference between mash efficiency and brewhouse efficiency. Mash efficiency is the percentage of potential sugars that are extracted in the mash/lauter process. Brewhouse efficiency is the percentage that makes it into the fermenter. Unless you dump the entire content of your boil kettle into the fermenter, brewhouse efficiency will always be lower because it takes post boll losses into consideration. Changing the boiloff will change the actual brewhouse efficiency which, in turn, will changer the estimated OG. To get the 2 to align, you will need to adjust the brewhouse efficiency.

Understand that changing a profile doesn't change an existing recipe unless you select the new profile in the original recipe. Each recipe is an individual archive.
Bob