GuitarLord5000
Apprentice
- Joined
- May 25, 2008
- Messages
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Hello,
Some time ago, I created an Excel based brewing spreadsheet that has similar features to Beersmith. I've always been happy with it's accuracy, as all of it's calculations are nearly identical in every respect to those from Beersmith. Very recently, I've been discussing IBU calculations with the designer of an up-and-coming brewing software utility, and I'm beginning to wonder if there might be a minor error in Beersmith's (and my own) default Tinseth IBU calculations.
According to various online sources, the Tinseth formula is used to figure out IBU's based on whole hop cones in the boil. Upward percentage adjustments can then be made to take into account the increase in IBU's from using Pellet or Plug hops. For my spreadsheet (and Beersmith?), I assumed that the formula figures out IBU's based on Pellet hops, and so I make a downward percentage adjustment to get my whole leaf and Plug hop bitterness units.
By using pellet hops as the Beersmith default, are we in fact getting lower than actual IBU figures? Or are the online sources wrong in that the Tinseth formula doesactually calculate for Pellet hop IBUs?
Sample Recipe:
Batch Size - 5.5 Gallons
Malt Bill - 5 lbs of 1.038 grain
Hop Bill - 1 ounce of 5.2 Alpha Acid hops - Boiled 60 minutes
OG Estimated at 75% efficiency - 1.026
IBUs = 20.7 (Pellet or Whole Hops?)
If Whole Hops is used as the default:
Whole = 20.7 IBUs
Pellet = 22.77 IBUs
Plug = 22.36 IBUs
If Pellet Hops is used as the default:
Whole = 18.6 IBUs
Pellet = 20.7 IBUs
Plug = 19.1 IBUs
Cheers,
Dave
Some time ago, I created an Excel based brewing spreadsheet that has similar features to Beersmith. I've always been happy with it's accuracy, as all of it's calculations are nearly identical in every respect to those from Beersmith. Very recently, I've been discussing IBU calculations with the designer of an up-and-coming brewing software utility, and I'm beginning to wonder if there might be a minor error in Beersmith's (and my own) default Tinseth IBU calculations.
According to various online sources, the Tinseth formula is used to figure out IBU's based on whole hop cones in the boil. Upward percentage adjustments can then be made to take into account the increase in IBU's from using Pellet or Plug hops. For my spreadsheet (and Beersmith?), I assumed that the formula figures out IBU's based on Pellet hops, and so I make a downward percentage adjustment to get my whole leaf and Plug hop bitterness units.
By using pellet hops as the Beersmith default, are we in fact getting lower than actual IBU figures? Or are the online sources wrong in that the Tinseth formula doesactually calculate for Pellet hop IBUs?
Sample Recipe:
Batch Size - 5.5 Gallons
Malt Bill - 5 lbs of 1.038 grain
Hop Bill - 1 ounce of 5.2 Alpha Acid hops - Boiled 60 minutes
OG Estimated at 75% efficiency - 1.026
IBUs = 20.7 (Pellet or Whole Hops?)
If Whole Hops is used as the default:
Whole = 20.7 IBUs
Pellet = 22.77 IBUs
Plug = 22.36 IBUs
If Pellet Hops is used as the default:
Whole = 18.6 IBUs
Pellet = 20.7 IBUs
Plug = 19.1 IBUs
Cheers,
Dave