Alpha Acid

[Gmull70]

So I brewd a 5 gallon batch about 6 daus ago. It called for Columbus 13.4 AA, Fuggles 3.9 AA, and Kent Goldings 4.5 AA. This is what the home brew shop had, Columbus 19.4 AA, Fuggles 4.3 AA, and Kent Goldings 5.6.
After looking at the recipe and taking note of the IBUs I pluged the info I had into the brewing software I use (Brewers Friend) and backed off the amount of hops to get as close as I could to the recipes IBUs. The original recipe called stated it would have an IBU of 9.5 and after backing my hops down to 1/4 oz I got the IBUs down to 16.5.
After tasting the sample from my first hydrometer test today six days later I think the beer will turn out fine. I would like to know what other home brewers do When faced with this problem? I there some type of hop calculator that would help with this problem. I also would have brought the hops down more if I had the ability to weigh less than 1/4 oz. myt scale does go to grams but im not thinking it is accurate at such a low weight.
thanks for reading Greg

 

[ncbrewer]

From the way I read your post, I do about the same thing that you did by running it through some software or my own spreadsheet. A couple of items - 1) 9.5 IBU seems really low for most beers. Is it a hefeweizen, or something similar? Try running the original recipe through the software as a double check. 2) If the Fuggles and/or Kent Goldings are finishing hops, I'd leave the quantities of those alone and adjust the bitterness with the bittering hops only. Good luck.

 

[zachattack]

Agreed. I'd keep the flavor/aroma hops the same and back off on the bittering charge @ 60 minutes until the IBUs are as intended.

 

[Gmull70]

Thanks for the replys just an FYI I got the recipe for emailing the brewer at flying fish brewery I tried their ESB Amber and really liked it. The brewer told me he couldn't brake down the recipe for me but gave me a list of grains with the percentages and he listed the hops and the alpha acids not the amounts. The IBUs I got from the description of the beer from the Web site. It's been a long time since I drank the beer but I remember the hops being just noticeable.