Originally Posted by 668
...What is the method for calculating final alcohol percentage in a recipe such as this blueberry mead
in the recipe section of this site where some of the honey is continually added at each racking?
It is possible to calculate a close estimate of the final ABV for this recipe. However, to do it requires information not provided.
Central to the calculation is knowing the must volume after various steps, and the anticipated FG. While the recipe starts off with the required information, it stops short of mentioning what the must volume should be after adding the berries.
The effect of adding honey in increments later in the process (for sweetening) is most likely performed after fermentation has ended. In this case, the honey serves to dilute the existing ABV rather than add to it as there would be no expectation for additional fermentation.
My last online group brew (a Riesling pyment) used a recipe that had late honey additions that did add to the ABV, and an even later addition of concentrated Riesling juice for sweetening that served to dilute the ABV.
The calculation you seek can be performed, but it requires a level of information detail not present in the recipe you will be using...