Recipe conversion help - 5 Gal to partial boil

[chainsmoke]

Hey all,
I'm trying to convert this recipe from a 5.5 gallon batch to a partial boil.

I'm doing this because I don't have a wort chiller yet.

I find Beersmith new and tricky. What I did was change the pre-boil volume from 5.5gal to 2gal. This caused the IBU's to drop. I then put the IBUs back to the full boil levels which adjusted the hops.

If I drop it to a 2 gallon boil I'm getting these hop measurements
6.17 oz @ 15min vs. 2.5 oz @ 15(with full boil)
2.47 oz @ 5min vs. 1 oz @ 5 (with full boil)

If it up it to a 2.5 gallon boil I get to use a couple ounces less hops.
4.64 @ 15
1.86 @ 5

Does this look right? This recipe was attractive to me for its simplicity... but the cost of the hops increase isn't so hot!

Thanks!

 

[Jayhem]

I also found beersmith to be a bit tricky especially for a beginner.

I have found beer calculus to be much easier to work with to get a start on recipe buildings as it allows you to input batch size and partial boil size and it adjusts the IBU's based on these inputs well.

http://beercalculus.hopville.com/recipe

 

[orcus332]

I think your manipulation of the hop weights to get your desired IBUs is correct.
Unless you're really strapped for time, why not just boil for 60 minutes? That will help you get more out of your hops anyway, so it will be cheaper. Here's a sample recipe that gets you close. I'm not sure how they got their OG so high, but anyway.

Batch Size: 5.50 gal
Boil Size: 2.00 gal
Estimated OG: 1.049 SG
Estimated Color: 11.5 SRM
Estimated IBU: 35.7 IBU
Brewhouse Efficiency: - %
Boil Time: 60 Minutes

Ingredients:
------------
Amount Item Type % or IBU
6 lbs Light Dry Extract (8.0 SRM) Dry Extract 85.71 %
1 lbs Caramel/Crystal Malt - 60L (60.0 SRM) Grain 14.29 %
1.00 oz Cascade [7.50 %] (60 min) Hops 11.1 IBU
1.00 oz Cascade [7.50 %] (Dry Hop 7 days) Hops -
1.00 oz Cascade [7.50 %] (5 min) Hops 2.2 IBU
0.50 oz Cascade [7.50 %] (0 min) Hops -

And it should be noted that the DME for my rendition was added in the last 15 minutes of the boil. If you boil it for 60 minutes with the hops your IBU's would only be around 15.

 

[chainsmoke]

Thanks for the info guys. Beercalculus is cool and was easy. It confirmed my beersmith findings.

I liked the idea of the quick brew day of the 15 minute recipe but if I decide to brew it I'll do an hour long brew like orcus suggests. The 15 minute partial brew would waste a lot of hops.