Author Topic: Partial Mash OG higher than predicted  (Read 2952 times)

Offline SleepySamSlim

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Partial Mash OG higher than predicted
« on: April 12, 2009, 10:28:16 PM »
So as one of my other threads indicates --- I'm using Jamil's Stove Top Partial Mash method and of course using BeerSmith to model the recipe. So I entered the original extract recipe - then ran the BeerSmith converter to partial mash.

I then tweaked the specialty grains a bit to boost the toffee/carmel flavor and to bring up the predicted OG to 1.051. We brewed today (the kitchen is still a mess - argh) and the measured OG is 1.061 (temperature corrected). Thats a fair bit off the mark - any ideas on this ? I've attached the recipe and you can find a description of Jamils method in my other thread.

Thanks for any insight

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Offline MaltLicker

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Re: Partial Mash OG higher than predicted
« Reply #1 on: April 13, 2009, 06:34:59 AM »
With the mini-mash at only 2# of the fermentables, no realistic EE% would achieve 1.061, so I'd guess the amount of water used was lower than calculated.   Or you boiled off more water than expected.

Any chance you had 6# of LME and not 5#? 

Less likely, in looking at the primary fermentables (LME and grains) in the inventory lists, I see variance in their PPG from 1.035 to 1.038.  Is it possible your pale malt, LME, etc., were each slightly higher than what his recipe used?   That could be a few points worth, but the water is most likely the issue. 

Est Pre_Boil Gravity: 1.073   Est OG: 1.052 SG

The estimated pre-boil gravity was 1.073, and a 60-minute boil would concentrate it to approx. 1.081, so it was expecting 31 points of dilution IOT hit 1.052. 

Refractometers really help with this problem.  A refract makes it easy to check the pre-boil gravity and again at 15 minutes remaining to ensure you're close to your targets.  If SG is high, add water.  SG low, add some DME.