Calculating Mash Efficiency

[brandonlovesbeer]

How do you calculate Mash Efficiency?
Is there an equation that someone can share?

Thanks

 

[Big Monk]

How do you calculate Mash Efficiency?

Is there an equation that someone can share?



Thanks

Mash η is the product of Conversion η and Lauter η.

 

[day_trippr]

There are "mash efficiency" calculators and "brewhouse efficiency" calculators.

The former considers the 100% potential of the grain bill as a base, takes the volume and gravity at the pre and/or post-boil phase, and stops right there (if post-boil is used that will usually include boil kettle loss as well).

The latter adds in product losses through the whole brew process all the way through the packaging phase.

For just the mash efficiency metric, this is a decent calculator.
It's titled Brewhouse Efficiency, but when you actually look at the data inputs, it's strictly a pre-boil calculator...
http://www.brewersfriend.com/brewhouse-efficiency/

Cheers!

 

[Big Monk]

The hand calculation would look something like this:

η (conversion) * η (lauter)

Where η (lauter) is:

Vol. (Strike) - Vol. (Absorption) - Vol. (Deadspace)

There are a couple of points to note:

1.) 100% conversion means that your mash η is equal to your lauter η.

2.) minimizing dead space means that your mash η is only limited by the amount of grain you use. For instance, many people have bottom drain MLTs. This essentially eliminates dead space and means that even with a No-Sparge mash, η in the high 80s is possible with a 12 °P wort.

 

[ba-brewer]

This is the page I look at when I need to refresh my memory.
http://braukaiser.com/wiki/index.php?title=Understanding_Efficiency

 

[schokie]

Without getting into complicated formulas, it's simply the sugars extracted divided by the potential maximum extraction. I find it easiest to work in points per pound per gallon. That's PPPG to be correct, though most folks abbreviate it PPG for ease and simplicity.

Reference this table in How To Brew:
http://howtobrew.com/book/section-2/what-is-malted-grain/table-of-typical-malt-yields

Find the closest match to the grain you're using. Just get close, a couple points off won't make a big difference. Multiply the pounds of grain with the 'Max PPG'. That gives you the maximum potential extract of your mash.

Now you need the PPG of your mash. You'll have to measure volume and gravity in SG. Take everything in the SG after the 1. Now multiply by the volume in gallons. Divide that number by the maximum potential extract, then multiply by 100. That's your mash efficiency.

Example:

I mashed 7 lbs of pale malt and 1/2 lb of crystal 120 for my Bitter. That gives a max PPG of (7x38)+(.5x33)=282.5 PPG.

Now after my mash and sparge, but before the boil, I have 6.5 gals of wort at an SG of 1.031. I multiply 31 x 6.5 to get 201.5 PPG actual.

201.5/282.5= 0.713. Multiply by 100 for 71.3% mash efficiency.

If you measure in liters and degrees Plato or Balling then you'll have to convert to gallons and SG for ease of calculation.