Adjusting kit recipe with Beer Alchemy etc.. - Home Brew Forums
Register Now For Free!

Home Brew Forums > Home Brewing Beer > Beginners Beer Brewing Forum > Adjusting kit recipe with Beer Alchemy etc..

Thread Tools
Old 10-23-2009, 01:26 AM   #1
Oct 2009
Winona, MN
Posts: 15

For my second batch of homebrew I'm making a Belgian Tripel from a kit. The kit recipe calls for a 2.5 gallon boil, but I have the capacity to boil the full batch if desired. I played with the hops calculator in my demo version of Beer Alchemy to figure out the hops adjustment for a full boil, but it isn't making sense to me. The kit describes the OG as 1.083-1.086 and IBU 24-30. The hops in the kit are 2 oz of "Kent Bittering Hops" (4.9% AAU) to go in at 60 min, and 0.5 oz of "Kent Aroma Hops" (4.6% AAU) to go in at 15 minutes.

If I plug into BA wort gravity of 1.085 (is this the right number to use for wort gravity?), a 6 gallon boil and the hops mentioned, assuming pellets in a bag and Tinseth calculations, I end up with an IBU of only 24 - barely into the style range. Doesn't seem right considering these are all the hops used for a smaller volume boil. Also, how could I work backwards to see how much bitterness the hops add to the original 2.5 gallon recipe without knowing what the gravity of the 2.5 gallons is? The big question, though - How do I calculate hops adjustments when going from partial boil to full boil?

Also, the kit contains an 11g packet of Nottingham yeast. This seems like the wrong kind of yeast to me. Should I substitute a Trappist yeast instead? And what adjustment should I make to fermentation if I switch yeast?

Reply With Quote
Old 10-23-2009, 02:18 AM   #2
Senior Member
ajf's Avatar
Oct 2005
Long Island
Posts: 4,646
Liked 106 Times on 100 Posts

I'm not going to try to answer the yeast question, because I know diddly about Belgian Tripels.
As for the hops, it doesn't look too bad.
If you are using Tinseth, then 1.085 is not the right gravity to use. You need to use the average gravity. If you are boiling 6g down to 5, and your OG is 1.085, your pre-boil gravity will be (1.085 - 1.000) * 5 / 6 + 1.000 = 1.070. The average gravity would therefore be 1.0775.
I ran it through Promash using Tinseth and pellet hops, and got an IBU of 34.5
This will be very slightly higher than your figure because my Promash is set up to boil off more than 1g, but the difference will be very small.
If you really want to calculate the IBU's without software, you can see but this is likely to give you a headache

There are only 10 types of people in this world. Those that understand binary, and those that don't.

Reply With Quote
Thread Tools

Similar Threads
Thread Thread Starter Forum Replies Last Post
Beer Alchemy help EamusCatuli Brewing Software 3 03-25-2013 03:14 AM
Beer Alchemy Recipe Swap (Mac) Seawolf Recipes/Ingredients 23 09-20-2010 08:45 PM
Beer Alchemy tun t/m? chirs Brewing Software 3 10-31-2009 07:12 PM
dunkelweiss: OG in beer alchemy way different from recipe book jigidyjim Beginners Beer Brewing Forum 2 08-10-2009 04:55 AM
Beer Alchemy Laurel Brewing Software 4 09-11-2008 10:04 PM

Forum Jump