Coldbreak Brewing HERMS Giveaway!

HomeBrewSupply AMCYL Brew Kettle Giveaway!


Home Brew Forums > Home Brewing Beer > Brewing Software > BeerSmith IBU calculations
Reply
 
Thread Tools
Old 10-13-2009, 05:21 PM   #1
JoePat
Feedback Score: 0 reviews
Recipes 
 
Join Date: Apr 2009
Posts: 5
Default BeerSmith IBU calculations

am making a recipe for a beer with a SG of about 1.107 my plan was to do 2 brews at the same time (with a friend) and one would be just base malt and get a 3 hour boil to caramelize the sugars and the other would have the same SG but I would use some darker malts (120L and special B) to get the caramel and roasted flavors with a 60 min boil. We were thinking at setting the IBUís between 50-60 and I made the 3 hour boil recipe first in BeerSmith set the hop amounts to reach the IBUís we desired. Once finished with the recipe I copied it and went to change the grains but first I changed the boil time from 180min to 60min and I noted the IBUís went way down. I played with all 3 bitterness calculations in beer smith and with everything equal only the boil time different (not the amount of time the hops are boiledÖsee below hop schedule same for both) I am getting huge difference in IBUís. My question is how can boiling for 2 hours before adding my hops change my IBUís or is this just a glitch in BeerSmith? Both the 60 min addition and the 15min addition changed the amount of IBUís it contributed.



Below is my hop schedule from BeerSmith:

1.50 oz Simcoe [11.90 %] (60 min)
1.00 oz Amarillo [8.20 %] (15 min)



Below is the difference in IBUís per boil time.

60 min Boil | 180 min Boil

Tenseth 52.0 IBU | 60.9 IBU

Rager 74.2 IBU | 80.2 IBU

Garetz 41.5 IBU | 44.5 IBU


JoePat is offline
 
Reply With Quote
Old 10-13-2009, 06:02 PM   #2
ArcaneXor
Feedback Score: 0 reviews
Recipes 
 
Join Date: Nov 2007
Posts: 4,559
Liked 112 Times on 100 Posts
Likes Given: 32

Default

Did you keep the boil volume the same for the 3 and 1-hour boils?
ArcaneXor is offline
 
Reply With Quote
Old 10-13-2009, 07:17 PM   #3
JoePat
Feedback Score: 0 reviews
Recipes 
 
Join Date: Apr 2009
Posts: 5
Default

No boil volume is set to equipment. 8.5 gal on 3 hour boil and 6.34 gal for 1 hour boil both going to 5 gal. I went in and changed it to the same and it evened it out the IBUís but that still does not make sense with program having the ability to specify the boil time. If I start with 8.5 and boil down to 6.34 over 2 hours and add the hops isnít it the same as if I started the boil at 6.34 gal and add the hops? Or is BeerSmith using the boil volume to calculate the SG of the wort for hop utilization? That would make some sense because the utilization factor goes up the lower the gravity. Still I think this is a mistake in the program there should be a linear scale for the hop utilization as the volume goes down and SG goes up. I guess I will just have to fudge my boil volume to get the correct IBUís on the recipe print out since as far as the hops are concerned this is a 1 hour boil and the SG of the wort will be at the 1 hour boil level. If I am wrong in my assumption let me know otherwise thanks for the help.
JoePat is offline
 
Reply With Quote
Reply


Thread Tools


Similar Threads
Thread Thread Starter Forum Replies Last Post
Are my calculations right? thorson138 Mead Forum 4 09-09-2009 12:46 PM
Beersmith, IBU calculations, and full boils... BigdogMark Brewing Software 1 08-11-2009 03:25 AM
Need help with calculations telebrewer All Grain & Partial Mash Brewing 1 04-03-2009 04:05 AM
My calculations are off????? histo320 Beginners Beer Brewing Forum 4 12-11-2008 01:18 AM
Calculations??? attitude General Beer Discussion 2 04-01-2007 02:51 AM


Forum Jump

Newest Threads

LATEST SPONSOR DEALS