Questions about partial boil, late extract addition, and hop utilization

[dsaavedra]

Background: So I think my last couple of brews (extract kits with specialty grains) have been suffering from extract twang. I do a partial boil (about 2.5-3 gallons) in a 5 gallon kettle on the stove top. My first two brews used LME and both had this very distinct flavor that I didn't really like. My third brew used only DME and I haven't tried it yet, going to bottle it this weekend. I'll be interested to see if it has the same flavor. My next brew is going to be an IPA with LME and I want to not only make it taste better than my first two brews, but I also want to get the most out of my hops.

The Setup: I was poking around in the search looking up late extract additions. From what I gathered, a volume of liquid can extract a finite amount of alpha acids from hops, and this is dependent on gravity of that liquid. A volume of wort will max out at 100 IBU's. But by doing a partial boil, even if I got perfect hop utilization and reached 100 IBU's in my 2.5 gallons, when I top off with 2.5 gallons of plain water, I will only have 50 IBU's in my final product. It also seems to be the consensus that doing late extract additions lowers the gravity and allows for better hop utilization, and the amount of hops should be cut back 20-25% to account for this.

The Question: So my IPA is supposed to have 80-something IBU's. I realize that this is going to be pretty difficult to achieve doing a partial boil. I was thinking though, if I boil as much wort as I can in my 5 gallon kettle (probably 3, maybe 3.5 gallons) this will cut back on the dilution effect of topping off. Adding most of the extract toward the end of the boil (or maybe even at flameout?) should increase the hop utilization as well. If I boil as much wort as possible, add most of the extract late, and don't cut back on my hop amounts, will this get me the most IBU's as possible in the final product given my limitations?

This all makes sense in my head and seems like it will get me the best brew possible with my current setup (I am planning on getting a 10.5-11 gallon kettle and doing BIAB), but I just wanted to check with the experts.

 

[dsaavedra]

I just saw a post that recommended boiling half of the bittering hops in the top-off water and chilling overnight before brewday to try and retain to some IBU's in a partial boil. This is an interesting concept that never occurred to me. Anybody have any experience with this?

 

[flars]

I'm not an expert, but I looked around a bit for some information. I played with this calculator with some of your numbers. You will need to estimate target OG for the amount of extract added at the beginning of the boil.
http://www.brewersfriend.com/ibu-calculator/

I don't believe there is such a thing as extract twang. In my opinion off flavors that are not dominant in a beer have other underlying causes. Off flavors could begin with the boil intensity, yeast health and pitch rate, fermentation temps not in the ideal range for the yeast, or brewing water.

 

[unionrdr]

Since I started dialing in Beersmith2,it's been giving me good IBU numbers with pb/pm biab. I too use a 5 gallon SS BK/MT. I typically mash 5-6lbs of grain in 2 gallons of spring water,sparging with 1.5 gallons @ 170F. This gives a 3.5 gallon boil volume. I don't cut back on hop amounts,as I feel from BS2 equipment set up,etc that the IBU's & all will be right when topped off. My beers have definitely gotten crisper as a result. I think the bittering to style part of the program helps a lot when you set everything up to accurately reflect your brewing style. Not to mention,the style of beer.
I use the resulting mashed wort for all hop additions. The extract,usually plain DME goes in at flame out for lighter color & no twang.

 

[brew_ny]

I only did a couple PM and Extract brews to learn how to start brewing

I use this http://www.brewersfriend.com/homebrew/recipe/calculator/

I thought it work well as it allows you to plug in the type of brew you want to do

as I am sure other brewing software does, I did find it easy to use

my first all grain brew was an extract recipe I brewed and they tasted the same

with the lower volume boils you need more hops but the software will tell you

good luck and all the best

S_M

 

[unionrdr]

Yeah,in the recipe calculators used,some tweaking is in order to get it "to style". But equipment,brewing style,partial boil,etc have to be tweaked as well to get an accurate result. I'm still learning with BS2.

 

[dsaavedra]

When I used the brewer's friend calculator and selected Extract as the brewing style, 5 gallon as the batch size, and 3 gallon as the boil size, put in all my LME and hops, it said I'd get around 68 IBU's (the recipe in the kit says it should be about 82 IBU's). Does this mean that my 3 gallon boil will have 68 IBU's, or will I get 68 IBU's in my final product after I top off with the remaining 2 gallons of water?

How would I have to tweak this calculator to account for a late LME addition? This should increase my IBU's right? I noticed if I only put in the calculator that I was adding 4 or 5 pounds of LME (out of 9.15lbs total) and kept everything else the same, my IBU's shot above 100. Is this the same thing as telling the calculator I'm only going to boil half the extract with the hops, then add the rest of the extract at flameout?

Is it even possible for me to get my IBU's up where the recipe calls for using a partial boil? I realize I could probably split all the ingredients in half and brew two half-batches and combine them to avoid the dilution from topping off, but I'd rather not do this as it would take all day.

 

[brew_ny]

if you need 82 then you will need to increase your hops

can you up the recipe or link so wee can look with you ?

all the best

S_M

 

[unionrdr]

Did you set the recipe as being for 5 gallons? Set the top off amount? That could be it.

 

[dsaavedra]

Recipe is here: http://www.midwestsupplies.com/media/downloads/524/Ferocious Instructions.pdf

I have also been playing around with this recipe: http://www.midwestsupplies.com/media/downloads/49/hop_head_double_ipa_instructions.pdf and I am getting even fewer IBU's with this one

On the calculators (both the recipe calculator and the IBU calculator) I did set the batch size as 5 gallons. I did not see a place to enter a top-off volume, but I did set my boil size to 3 gallons. Does the calculator automatically do the math and assume I am using 2 gallons of top-off?