Is it normal for a beer to evaporate 1/2-3/4 gallon during primary fermentation?
I brewed an extract beer last week, an Imperial Rye IPA, and went to rack it into the secondary and then dry hop it. However, after racking it into the secondary, I saw that I had only 4 gallons of beer having left the yeast mass and other fermentation debris at the bottom of the primary (all of which added up to about 1/4 gallon). The OG was 1.080 and prior to racking it into the secondary it was 1.016.
Would it be bad to top it off with water in the secondary?
For reference the recipe I followed is here: http://beerrecipes.org/showrecipe.php?recipeid=1290