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 Home Brew Forums > Estimating Quantity to Calculate Efficiency on the Fly
06-15-2012, 05:39 PM   #1
kopher
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 Estimating Quantity to Calculate Efficiency on the Fly

I've only done a few all-grain batches and my efficiency is still all over the place. I like to calculate efficiency when I start the boil so I know if I should add a little extract or maybe change IBUs if it looks like I'm gonna miss my target OG.

I've got a refractometer to measure the gravity but no good way to tell how much liquid I have. I usually use 2 pots (a second smaller one with last batch of batch sparge) so I can get a better boil. Right now I use my stirring spoon to see how many inches of liquid I have in each pot and then use an Excel sheet I set up to convert each to gallons and then take the weighted average of my gravity calculations, weighted by the two amounts of liquid, and then divide by 5 to get OG.

This system is insane, obviously. Any ideas? I'm thinking a plastic stick with markings on it would at least help, but I dunno.

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06-15-2012, 05:45 PM   #2
TyTanium
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Lots of options. I just use a notched wooden stick, marked in 1g increments. Not terribly precise, but functional. I wouldn't use plastic in boiling liquids. Another, and more reliable option is a sight class, or marking your kettle. Or, measure volume as you sparge. Have a 1qt pyrex measuring glass? I've done that before...kind of annoying, but very precise.

Also remember to account for expansion. ~4% at boiling vs 60°

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06-18-2012, 07:09 PM   #3
kopher
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That's a good idea, thanks. What kind of wood do you use? Do you need to make sure it's not treated with something poisonous? And do you not worry about it getting infected? I mean even if you only use it during the boil I wouldn't want to stick a really funky stick right into the wort, especially if trying to test it near the end of the boil...
I was thinking plastic like the type stirring spoons are made out of, but wood would be easier to notch and stuff.

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06-18-2012, 07:12 PM   #4
TyTanium
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Quote:
 Originally Posted by kopher That's a good idea, thanks. What kind of wood do you use? Do you need to make sure it's not treated with something poisonous? And do you not worry about it getting infected? I mean even if you only use it during the boil I wouldn't want to stick a really funky stick right into the wort, especially if trying to test it near the end of the boil... I was thinking plastic like the type stirring spoons are made out of, but wood would be easier to notch and stuff.
I just used an old scrap of untreated molding...pine or oak. Definitely use untreated. Oak or maple or something non-poisonous is preferred

I stop using it once my chiller is in (since that displaces volume), thus no fear of infection (still 15 mins left in boil).

Mostly I just use it as a gauge for my sparge runnings & pre-boil volume.
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