Brewing Strong to Dilute

[tommybrew123]

This may have been covered elsewhere, so if you could point me in the right direction that would be great.

I used to brew every two weeks, but now can only do it once a month. I want to brew a double strength batch and then dilute it out to make ten gallons when I go into the fermentor. So, basically I want to boil enough wort for ten gallons in a four gallon pot.

What issues will come up? I am thinking the hop utilization may not be as good. Anything else you can think of that would help make this work? I am thinking to try this first with a mid range brown ale or an amber.

Thanks

 

[Beernik]

I'd approach it the same way as partial boils. In theory, you could target a post boil OG of 1.100 and 5 gallons. Dilute it to 1.050 and 10 gallons. Ferment it down to 1.012 and make 5% beers.

You are correct, hop utilization goes down as SG goes up.

I think the real trick is ensuring a homogenous dilution.

 

[tommybrew123]

A red ale partial mash recipe I am considering for this would be something like:

14 lbs Pilsner Extract
1.5 lbs Munich Extract
.25 lbs chocolate 225L
1 lb Caramel 120
1 lb Victory
2 lbs caramel 40
2 lbs brewers malt

Then
1 oz Magnum (60 min)
1 oz Cascade (10 Min)
1 oz Centenial (10 min)
1 oz Cascade (0 min)
1 oz Centenial (0 min)

I think this would yield around 1.059 and 26 IBU in the final product.

Thanks for any suggestions.

 

[tommybrew123]

Thanks Beernik. I would boil it in a five gallon pot, then split it into two fermentors, about two gallons into each, and then dilute with pre-boiled water before pitching the yeast. I think it would be roughly the same in each carboy then.

Do you think I should go up on the magnum (bittering hops) by maybe 20% or something?

Thanks

 

[Beernik]

Its not an easy calculation & I'm half way through an 8.4% DIPA. You'll want to use an IBU calculator then multiply it by your dilution factor to be sure of what your end IBUs will be.

 

[tommybrew123]

Another idea I had was to mash the grain, then boil the hops for 30 minutes before adding the extract for another 60 minutes. That would up the bitterness from the hops?

 

[tommybrew123]

Yeah, when I used my IBU calculator I came up with

1.7 oz Magnum
1.5 Cascade and Centenial (10 min)
1 Cascade and Centenial (0 min)

giving me 53 IBU which is twice the 26 of the original recipe.

 

[tommybrew123]

I guess an extra .7 oz of magnum , .5 oz Cascade, and .5 oz Centenial is a small price to pay for brewing only once instead of twice.

Anything else anyone can think of?

Thanks

 

[Beernik]

It's going to be more than twice the hops of a lower gravity recipe. You need a calculator that uses the "bigness factor" of the wort. Or you you can do it by hand http://realbeer.com/hops/research.html.