Partial to Full Boil & Hop Reduction

[illin8]

I am looking to do this AHS Stout as a full boil instead of the partial (2 1/2 gallons) that is directed...Can anyone advise as to what I should do to modify the recipe based on the full boil? Thanks

3/4 lb Chocolate
1/4 lb Crystal 40L
1/8 lb Roasted Barley
1/2 lb 2-row
1/8 lb Black Patent
1/2 lb Malto Dextrin
7 lb amber extract
1 oz Premiant @ 60
1 oz unsweetened cocoa @ 5
Wyeast British Ale 1098

How much water should I start with (Bayou Classic).?

 

[BeerSmith]

Hmmm,
I calculated <15 IBUs (Tinseth) bitterness using BeerSmith (I assumed that the hop alpha was about 7.5%).

Scaling that up to a 6 gallon boil you need only 0.55 oz of hops. The rest of the recipe can stay the same.

However, I would personally step the IBUS up a bit to at least 20-25 IBUs (minimum) which would be 3/4 oz of hops for 60 minutes.

Cheers,
Brad

 

[homebrewer_99]

The only thing you have to change from using a partial or full boil is the amount of hops you use.

What Beersmith said...

 

[TexLaw]

On your starting water, you will just have to find out what your evaporation rate is. You cannot know what it is until you've actually done such a boil, but most folks evaporate between 1 and 1.5 gallons per hour.


TL

 

[FishinDave07]

On your starting water, you will just have to find out what your evaporation rate is. You cannot know what it is until you've actually done such a boil, but most folks evaporate between 1 and 1.5 gallons per hour.


TL

+1 i did an evaporation test, i boil EXACTLY 1.5 gallons off, and used 5 gallons of hot water to test the new Mash/Lauter Tun.

 

[illin8]

Thanks for the replies...could you also kindly test my logic here.

I use the Bayou Classic 30 qt (7.5 gal to the top)...if I start with say 6 gallons, steep, boil, add extract, defend against boil overs, could I top off during the last 20 minutes or so? I'd imagine I'd have to add a little at a time to maintain the boil and not bring the wort temp down below boiling for any period of time. If thats the case, I think I just need to provide ample time to pasturize (15 mins of boiling). The overall goal would a wort of 5.25 gallons to account for .25 gallons of combined wort loss due to primary and secondary trub & hydrometer testing, or should I shoot for an extra 1/2 gallon?

Thanks again...I love this place