Sooo the other day I came across a great deal on a burner, and I picked it up. Shortly thereafter, I decided to bite the bullet and finally get myself a wort chiller and get real about this hobby. I'm putting together my first All-grain recipe (JP's Oatmeal Stout) and I'm running into a bit of an issue.

In the recipe, Northern Brewer is the bittering addition, 1.5 ounces for 60 minutes at 8% AA. British Kent Goldings is in there 1.5 ounces for the last 5 minutes at 7.2% AA. I decided I'd order from Brewmasters Warehouse, and on there they list their NB at 9.4% and their BKG at 5%. I figure some conversion is necessary.

So I used this site: http://www.jimsbeerkit.com/hop_calculat ... hopsubcalc
this told me that I'd need 2.5 ounces NB and 4.3 oz BKG. Does that sound right? I want to double check my numbers before I actually send the order off, and I don't know how reliable that calculator is. Is there a conversion chart or formula somewhere in how to brew or in other places online?

Thanks a lot guys, looking forward to getting this first batch under my belt as a Mufasa-approved brewer.

What's the total amount of IBUs you are shooting for? Also how many gallons are you brewing? These could help out in giving you a more definitive answer. You could use Beersmith, Promash, or less accurate but free....Qbrew, to put in your recipe and figure it out that way. Brewing software isn't always accurate, but really helps.

Sorry. 5 Gallon batch, and I'm not sure on the IBUs. I'm this recipe: http://moderndaymerrick.blogspot.com/20 ... stout.html

I'll check out the 21-day trial of beersmith when I get home and see what it says.

Sounds good. With Beersmith you can adjust the AA on the hops. Hope it helps. I bet you will end up buying that software. Good luck!

One thing to consider when you adjust hop amounts to account for %AA differences is that you should start with the late hops first, then add enough early/bittering hops to hit the target IBU levels. This is because the greatest factor added by the late hops will be the flavor and aroma components. As a general rule, the amount of flavor and aroma is pretty much the same even when the %AA is different. Therefore, you want to keep the late hops weights the same (those after around 20 mins). You plug them in using the new %AA values, but use the same weight. Then, use enough hops at 60 to make up any IBU differences, as that will have the least effect on hop flavor (as opposed to hop bitterness).

Hope this makes sense-

So in other words, what I'm getting out of finishing hops isn't bittering anything, it's all flavor and aroma? I might have known that and then forgotten it. It's been a little while since I threw some wort in a fermenter.

Edit: Okay, so I stuck the recipe into Beersmith, but the gravity isn't coming out right at all, and that's probably gonna throw the IBU's off, isn't it?

Edit2: So I ended up using 1.3 ounces of the bittering hops and keeping the late hop additions at 1.5 ounces. We'll see how it turns out.

You'll still get some bitterness for the late additions, but the %AA differences will have less effect on changing the total bitterness levels. Think of it this way -- Adding only 2/3 the flavor hops because the AA is higher will greatly lower the flavor. Think of flavor and aroma hops as constant with the weight. Use the Bittering addition to adjust total bitterness to compensate.


For a BIG beer (>1.070), yes, by a lot. For a medium sized beer(around 1.050), a bit. For a Small beer, not very much.



Good deal. That sounds about right.
Good luck!

Jake, I like the info that Bdawg gave on this and will keep that in mind myself. I also wanted to mention that you need to be mindfull of matching the IBU's from a recipe using the same scale it used, Rager and Tinseth supply very different #'s. I have been playing with Hopville's free recipe calculator where you can also load the known AAU's for each hop addition and chose between the 2 unit scales. I think JZ used Rager in his BCS recipes and a many others I look at are Tinseth.