Ask The Brewmasters

Hey Brewers,

I'm reaching out because I feel like there is an equation out there that I'm missing that hopefully can find. We are trying to figure out how much waste we are diverting from the landfill by sending our grain to Farmer Blair's Dairy Farm. I'd like to use Spent Grain weight. If we average 420lbs dry grain per batch, is there an equation that will give me the Spent grain weight? This doesn't need to be exact, more of an estimate. Thanks!

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Jon Hovan
Head Brewer
HiHO Brewing Co
Cuyahoga Falls OH
(330) 388-3708
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Hey Jon,

I'm not an expert on this topic, but I figure some simple math could be applicable...

420lbs. of "dry grain"... if your mash is 100% malted barley, you are working with a moisture content of about 5% w/w. 
Spent grain generally has a moisture content of 75-80% w/w if you are simply lautering off and not doing anything else to it. The extracted sugar and protein from the malted barley is fairly negligible in terms of weight. 
So we solve for "X", and get a range of 700-720lbs. should be your resultant weight of your spent malted barley per batch. 

If you are using flaked adjuncts, un-malted products, or raw grains the math will change as they have different moisture content and different extracts. 

Cheers!

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Jason McCammon
Technical Sales & Product Specialist
ATP Group
Denver, CO
720-788-1222
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