Belgian Dubbel

[quaboagbrewing]

Brewing the below recipe from Jasper Homebrewing in Nashua, NH. Questioning the hop additions. 1oz Magnum at 60 minutes seems like it will be too bitter for a Dubbel. They claim IBU's are 20 but my calculations come out to like 47. Should I tone down the bittering hops on this one or just go with the recipe as is?

5 Gallon Batch
BJCP Style: 18B. Belgian Dubbel
Original Specific Gravity: 1.066 - 1.070
Final Specific Gravity: 1.012 - 1.016
Alcohol by Volume: 7.1%
Color: 12 (Reddish-Amber & Double Your Pleasure!)
International Bittering Units: 20

Ingredients:
Fermentables:
7.9 lbs Light Malt Extract Syrup
1 lbs Amber Belgian Candi Sugar
Grains & Wort Additives:
4 oz Caramunich Malt (Crushed)
4 oz Special B Malt (Crushed)
1 Whirlfloc Tablet or 1 tsp. Irish Moss (Clarifier, 20 Minutes)

Hops:
1 oz Magnum Hops (Bittering, 60 Minutes)
½ oz Saaz Hops (Bittering, 60 Minutes)
½ oz Saaz Hops (Aroma, 1 Minute)

Yeast:
Wyeast 1214 Belgian Abbey

 

[giraffe]

You should use as much as will give you 20 ish ibus, that is what is important. Use a calculator. Hops vary in Alpha acids from harvest to harvest, it may be an old recipe they didnt update with a new crop.

 

[QuercusMax]

It also could be that the recipe is expecting you to do a partial boil instead of boiling the full volume. If you do a concentrated boil, you won't get as much bitterness.

 

[quaboagbrewing]

It also could be that the recipe is expecting you to do a partial boil instead of boiling the full volume. If you do a concentrated boil, you won't get as much bitterness.

Good point. Funny been while since I have done an extract batch that forgot that these recipes are written for a partial boil. This particular recipe actually only called for a 1.5 gallon boil. I'm going to do a full boil on this so I'm dropping the Magnum down to about .4oz at 60 which should put me around 23 IBU which should be more inline with the style.