Hop Utilization and (Quite Small) Partial Boils?

[BMGfan]

Hey folks, so here's the deal.

Up until now I've been doing the coopers no boil kits while refining my process. I tweaked them a bit, and done things like add fruit, and play with the various amounts and types of fermentables and such.

But now I want to do an IPA. Due to various reasons (related to living in BFE, limited access to ingredients, and a ****ty apartment stove), I'm limited to working with coopers kits and doing a 1.5 gal partial boil. Yes, I'm well aware that it's less than ideal, but it's what I've got to work with.

Recipe:
3.2lb can coopers IPA LME
2.2 pounds Light DME
3 lbs high malt brewing syrup (just to get the gravity points up)

1oz chinook (11.8 AA) @ 60
.5oz cascade (5.5 AA) @ 10
.5oz cascade dry hop


So the current plan is to do a 1.5 gal boil with the DME and syrup, and then add the LME and dilute to 5 gals. What I'm wondering is how the small boil size is going to affect IBUs. Beersmith is quoting me around 35.5 ibus...but it's also assuming a full boil I'm sure. Also I've only been able to get my hands on 1 oz each of cascade and chinook, so I can't really go higher than that.

Any suggestions on how I can make the best beer I can within these (admittedly ****ty) bounds?

 

[Grizzlybrew]

The gravity may be close to the actual. When I punch up the recipe doing a full boil, I get an OG of 1.072 and IBUs at 55 (rager), 35.1 (Garetz), and 46.7 (Tinseth) - not sure which one you use.

The smaller boil, with more concentrated wort, will reduce isomerization and result in a lower IBU rating. Although, if you're holding out some of the extract until the end, it may not affect it as much. It's hard to say how much it will actually affect it.

On a side note (and not to be a PITA), but 35 IBU's is not really enough to qualify an IPA. And, personally, I would use more than 2 oz total in an IPA; use 3-5 oz and definitely dry-hop. You're headed more to a pale ale here it seems.

As far as ingredients, use one of the fine online suppliers. I'm sure they all deliver to BFE.

Good luck!

 

[Yooper]

One thing you can do to get a better flavor is to add the bulk of the extract at flame out, just before you chill the wort. Use one pound of DME per gallon in the boil (so about 1.5 pounds of DME, give or take), and then add the rest of the extracts with just a few minutes left in the boil. That will help increase your hops utilization (as there won't be as much break material to cling to) as well as give you a less caramelized taste in the finished beer.

 

[aidan]

My approach with a partial boil is to use just enough malt in the boil to bring the BG to approx 1.040 - 1.050 (or what ever the SG of the beer is supposed to be). Then add the remaining malt at the end of the boil. Or better still, boil it in a second pot (just for 5 mins to sanitise it).

No need to be very exact with working out the BG as it's probably not as critical for hops utilization as the calculations make it appear. But with this approach there is no need to make any adjustments for hops utillisation based on BG.