Attenuation calculator

Discussion in 'General Brewing Discussions' started by Edan Z, Dec 6, 2017.

  1. Edan Z

    Edan Z Member

    Apr 26, 2017
    Likes Received:
    Trophy Points:
    I noticed that all my beers based on a similar recipe, pitched with a 1L starter of WLP530, starting at 1.063 OG, always finish up at 1.008 FG. According to the BF recipe calculator that corresponds to a "custom" attenuation of 84% for that yeast. I have gotten in the habit of using that custom attenuation figure in this recipe, since I know what my FG will be based on previous results with the same recipe/mash schedule, etc.

    I just noticed, however, that when I plug my figures into the BF stand-alone ABV calculator, the "apparent attenuation" given is slightly higher at 87%. All other figures match, except the % attenuation.

    I was wondering why there is a discrepancy between the recipe calculator and the ABV calculator in the attenuation figure. Does the recipe calculator figure refer something other than apparent attenuation?

    Incidentally, for my last brew, I actually forgot to make a starter before brew day. I started mashing before I realized I forgot the starter. It was a fresh (less than 30 days old) Wyeast 3787 activator pack. So I decided to bite the bullet and pitch it anyway. Fermentation took off fine in less than 12 hours as usual. Five days later the FG was at 1.010, and 10 days later is still 1.010. I was wondering if the attenuation is lower because I didn't make a starter, or because I added some crystal malt to the recipe, or maybe both?

Share This Page