I have a partial mash IPA recipe that i created and brewed. I created it on brewers friend and have been enjoying the beer. After switching to all grain, i went in to re-create my recipe. When i change my brew method from partial mash to AG, the IBUs double. Does anyone have any idea why this would be?
You typically get better hop utilization with AG. I believe this is due to the lower gravity boil. With AG brewing, you have a higher boil volume, so lower gravity boil than PM or extract (partial boil), hence better hop utilization. When brewing a PM or extract, people typically do a partial boil and have to make up for the top off water, so it’s necessary to use about 25% more hops in extract/PM.
If your estimated boil size and batch size are correct in Brewer’s Friend, and you correctly converted the extract to base malt for the AG recipe, then it should just be a matter of slightly reducing the hop additions to get the target IBUs.
Hope that helps