What is Malted Grain?
Extract Efficiency and Typical Yield
The maximum yield is just that, a value you might get if all the mash variables (e.g. pH, temperature, time, viscosity, grind, phase of the moon, etc.) lined up and 100% of the starches where converted to sugars. But most brewers, even commercial brewers, don't get that value in their mashes. Most brewers will approach 80 - 90% of the maximum yield (i.e. 90% of the maximum 80%). This percentage is referred to as a brewer's extract efficiency and the resulting yield is the typical yield from our mash. The extract efficiency is dependent on the mash conditions and the lautering system. This will be discussed further in Section 3 - Brewing Your First All-Grain Beer.
For the purposes of our discussion of the typical yields for the various malts and adjuncts, we will assume an extract efficiency of 85%, which is considered to be very good for homebrewers. A few points less yield (i.e. 80 or 75% extraction efficiency), is still considered to be good extraction. A large commercial brewery would see the 10% reduction as significant because they are using thousands of pounds of grain a day. For a homebrewer, adding 10% more grain per batch to make up for the difference in extraction is a pittance.