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Efficiency numbers on recipe sheet confusing


New Brewer
Nov 17, 2019
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I'm trying to understand Est Mash Eff vs. Meas Efficiency vs. Measured Mash Eff.  For example, on my last brew day, I exceeded my target gravity #s.  I have my BH efficiency set to 70%, because that's pretty much where I end up, for the most part.  On my last brew day, after entering all data in the recipe sheet after brewing, I got the following numbers:

Est Mash Eff = 75.8%

Meas Efficiency = 59.1%

Measured Mash Eff = 46.2%

I don't understand all these numbers, especially as they relate to one another.  If my estimated BH efficiency is 70%, and I met or exceeded my Estimated Pre-Boil Gravity and Starting Gravity, then I find it hard to believe that my mash efficiency really is 46.2%.  I mean...that's awful, no?


Grandmaster Brewer
Mar 16, 2013
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New Hampshire, US
When you make your equipment profile, you set the Brew House Efficiency (BHE) for your system.  BeerSmith back calculates how much sugar needs to come from the mash for a given recipe using this BHE from your equipment profile and gives you an Estimated Mash Efficiency.  Now, when you actually conduct your brew day and enter in the data for Measured Post Mash Gravity and Measured Pre-Boil Volume, the program uses these numbers to calculate your Measured Mash Efficiency.  Note that the efficiency calculations include not only the gravity readings but also the volume attained at the point you measure the gravity.

The program then uses your Measured OG and your Measured Batch Size to calculate your Measured Efficiency (which is really your measured BHE). 

Now, in general if you are getting all your sugars from your mash then your measured mash efficiency should be higher than your measured BHE.  When I see your measured mash efficiency at 46.2% and your measured efficiency at 59.1% I would immediately suspect that either you (a) are adding some sugars in your process in addition to those obtained from the grains (mash), or that something is wrong with your measurements. 

If you want some more specifics, export the recipe in question as a .bsmx file and post it here.  Once we have a chance to look at the whole process we can give you some idea of where something looks off.