Hop Utilization - Is there a minimum boil volume?!

[homebrewer_99]

So, let's say I want to brew an IPA soon, but its too cold to brew on the bayou burner/turkey frier, thus I'm restricted to a kitchen range (glass, electric top). I have trouble boiling 1.5g on this thing sometime...

My question is this. With a full boil, I may be able to draft up a good IPA using 4-6oz. of hops total (1-2oz. high alpha bittering, 1-2oz. flavor/flameout, 1-2oz. dryhop).

However, with a 1.0 - 1.5g boil and the (majorly) decreased utilization, this will drive my need for hops up to probably 10oz. or so. Obviously this makes brewing the IPA more expensive, but if I don't mind the increased cost of hops, is it possible to do an IPA with such a small boil?!

I'm wondering if there is a point where normal hop utilization theory goes out the window and you just can't get anymore hop bitterness into the water with such a small boil. If I can do an IPA with 1.0-1.5g boil, I know I'll basically need to double (or triple) the bittering and flavor hops to get the required IBU (I have beersmith so conversion is easy), but is it even possible?

I disagree with many comments about full boils versus small boils and hop utilization. Hop utilization is really a factor of the worts density, which is relative to malt to water ratio.

Checking Papazian's TCJOHB Hop Utilization Chart recommends 1 gal of water and 1 lb of DME equalling approximately 1.040. BYO uses 1.045.

Keeping along those lines, if you boil 2 gals of water and use 2 lbs of DME is the same. Most of the time I use 1.5-2 gals for my boils and use as little as 3% AA for a bacth of sweet-side Hefe Weizen...more for pale ales etc., but I'm not really a hop head.

 

[GNBrews]

Papazian's chart does predict ballpark hop utilization based on wort density, but not entirely for the right reason according to new research http://media.libsyn.com/media/basicbrewing/bbr03-20-08ibu.mp3.

What actually affects hop compounds making it into the final beer is the amount of surface area exposed to the hop compounds during the boil. The break material in the boil, similar to the pores in activated charcoal, "mop up" quite a large percentage of the iso alphas; the walls of the kettle as well. Because higher gravity worts tend to have more break, they affect hop utilization more negatively. Extract beers, already having much of the break removed during processing (there's still quite a bit of course), tend to get better utilization because of this.

My suggestion would be to add a small amount of extract (~.25lb) to the small boil volume, add your hops taking into account the low boil volume (and low gravity..which should even things out a bit), and do a late extract addition the last 15mins, topping-up with water in the fermenter. The late-extract addition should minimize break formation.

 

[GNBrews]

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