🍺 Top-down Brew: Mash Efficiency - Basic

Base grain potential specific gravity
Grain weight in pounds
Sweet wort specific gravity
Volume collected in gallons

Results *** Waiting for results ***


This calculator is a tutorial for illustrating the basic concept of mash efficiency. The process of sparging (rinsing) sugars from the mash grains is always less than 100% because some sugars will be left behind in the mash. Mash efficiency is a percentage of the sugars that are actually collected in the kettle from the grain bill.

A good source for grain potential extract values is the Brew United Grain Database. The malt producer may also have technical sheets with this value.

This calculator makes the simplifying assumption that all of the grains have the same degree of sugar as the base malt. In reality, specialty grains like crystal malt (example: 1.034) typically have lower amounts than the base malts (example: 1.037). This assumption may overestimate mash efficiency by a small amount, like 2 or 3%.

For basic mash efficiency it is important to know the sweet wort gravity before any sugar or malt extract is added to the wort. Use the advanced calculator for more complex situations with sugars or malt extracts.

Converting specific gravities to points (Step 1) isn't absolutely necessary but it is useful for making the calculations easier to understand.

This calculator is based upon US units: pounds and gallons.

Go back to the calculator list.

Creative Commons Attribution 4.0 International License that allows sharing, adapting, and remixing.