10 gallon partial boil batches...

[Horseballs]

I've been searching all of the forums for an answer about this, and nothing I've found as of yet has answered my question very well...

Basically, I've got a 13 gallon mash tun and a 10 gallon boil kettle. My idea is to do a partial boil using a very high gravity wort in my boil kettle and splitting and diluting them into two fermenters. I would be doing this with non-hoppy styles due to hop utilization stuff. Does this work well? Has anyone here ever done it? What styles would this work best with? Kolsch, cream ale, blonde, hefe?

I am brewing towards an event in august and my 5 gallon full boil batches have me worried about fermentation space and time.

Thanks.

 

[AmandaK]

I don't see a problem with this. Keep in mind that you'll only be able to brew lower gravity beers (~1.050) due to the limited space in your mash tun. And as you stated, less bitter beers will be better suited to this application.

However, there are many hop utilization calculators out there if you want to actually get it right. (HU is a factor of gravity, length of boil, AA%, bagged/not bagged, whole/pellet, etc, etc)

Although, I don't see how combining your boils will cut down on fermentation space/time. You still have the same amount of fermenters...

 

[Horseballs]

I don't see a problem with this. Keep in mind that you'll only be able to brew lower gravity beers (~1.050) due to the limited space in your mash tun. And as you stated, less bitter beers will be better suited to this application.

However, there are many hop utilization calculators out there if you want to actually get it right. (HU is a factor of gravity, length of boil, AA%, bagged/not bagged, whole/pellet, etc, etc)

Although, I don't see how combining your boils will cut down on fermentation space/time. You still have the same amount of fermenters...

Well, it will save on space because I wont need a bigger kettle and will save on time since I will be doing one boil for a 10 gallon batch rather than take the runnings, boil, chill, rack to fermenter, and the take the runnings and repeat again. I think I will be able to do a large variety of gravities with this tun, I can get about 33 lbs of grain into it if I need to. I only ask this because I want to get some positive feedback before going out and taking up fermentation space while on this deadline.

 

[tre9er]

I'm interested in this too. Are there any tools for figuring out what the IBU's will be after topping the batch up to 10g? I'm not much for the math on hops.

 

[D_Nyholm]

Yeah, I asked this similar question a while back and didn't get a final answer. I think I am going to try it the next time I here an oatmeal stout (just kegged one last week). I'll boil about 8 or 9 gallons and split it for me and a friend. I think it should work ok since it will only be around 28 lbs of grain. If I fall a little short, I am jot opposed to a beer with 4-5% instead of 5-6% as long as the flavor is there.

 

[tre9er]

Yeah, I asked this similar question a while back and didn't get a final answer. I think I am going to try it the next time I here an oatmeal stout (just kegged one last week). I'll boil about 8 or 9 gallons and split it for me and a friend. I think it should work ok since it will only be around 28 lbs of grain. If I fall a little short, I am jot opposed to a beer with 4-5% instead of 5-6% as long as the flavor is there.

I would use this method for lighter beers anyway, so I want to know for sure about the final IBU's calculations so I don't make a blonde that's hoppy as heck. Not great that way.

 

[D_Nyholm]

Don't partial boils use extract less ibus anyway? If that were the case, I would think IPA would be out, as well as any hoppy pa unless you up the hops. Am I on the right track?
My oatmeal stout (Yoopers recipe) uses 2 oz of williamette for 5 gallons, so I am thinking (without using a calculator) I might need 4.5 to 5 ounces instead for 10 gallons.

 

[Hopelesst]

I am not working on a ten gallon scale yet but I have a set up that forces me to use partial boils, so this thread interests me. My partial boils have worked just fine so far. There is something that's held me back though.

How do I figure out how far my gravity will drop when I dilute my wort? I can't hit my target gravity if I can't tell if my boil grav is to high or low.

 

[brewit2it]

I am not working on a ten gallon scale yet but I have a set up that forces me to use partial boils, so this thread interests me. My partial boils have worked just fine so far. There is something that's held me back though.

How do I figure out how far my gravity will drop when I dilute my wort? I can't hit my target gravity if I can't tell if my boil grav is to high or low.

It's just a simple proportion. As long as you know the pre-diluted gravity and volume, and your post diluted volume you just solve for the post diluted gravity.

In other words 5 gallons 1.050 diluted to 10 gallons will have a gravity of 1.025.

 

[ak-71]

Must be telepathy at work
I've just scaled my APA to 10 gal in Beersmith yesterday with exactly the same setup! From what I can see it does change hop utilization and didn't complain about cooler space for 1.56 OG recipe. I will need to check it's numbers for how much grain I can fit in my 52qt cooler to make sure it works (I should have bought a bigger kettle).
Not sure if I will do it but it's very tempting

 

[tre9er]

It's just a simple proportion. As long as you know the pre-diluted gravity and volume, and your post diluted volume you just solve for the post diluted gravity.

In other words 5 gallons 1.050 diluted to 10 gallons will have a gravity of 1.025.

Guessing IBU's would be the same then. ie. 36 IBU's in 5 gallons is 18 IBU in 10?

 

[ak-71]

My understanding is that more sugars => less hop utilization
Need more hops (relative) to get the same IBU's, I think

I mean in partial boil, which is the reason I do it because of a 10 gal kettle

 

[D_Nyholm]

Guessing IBU's would be the same then. ie. 36 IBU's in 5 gallons is 18 IBU in 10?

Yes, for cutting it in half, but if you do partial boils with the correct number of hops, you will not get the same IBU. If you mash enough grains for 1.050 10 gallons, and just double the hops, you will not get the same IBU. The partial boil would have less IBU than a full boil of the same amount of hops. At least that is my understanding.

 

[D_Nyholm]

My understanding is that more sugars => less hop utilization
Need more hops (relative) to get the same IBU's, I think

Yup, you said it much better than I did!

 

[tre9er]

Yes, for cutting it in half, but if you do partial boils with the correct number of hops, you will not get the same IBU. If you mash enough grains for 1.050 10 gallons, and just double the hops, you will not get the same IBU. The partial boil would have less IBU than a full boil of the same amount of hops. At least that is my understanding.

No, I would formulate a recipe for 5g batch, high gravity, then do the dilution calculations on my own. Ie. if a 5g batch of 1.080 wort creates 36 IBU's, I know when I dilute wort after cooling I will have 18 IBU's for resultant 10g batch. and 1.040 gravity.

 

[brewit2it]

No, I would formulate a recipe for 5g batch, high gravity, then do the dilution calculations on my own. Ie. if a 5g batch of 1.080 wort creates 36 IBU's, I know when I dilute wort after cooling I will have 18 IBU's for resultant 10g batch. and 1.040 gravity.

Yes, that is correct.

 

[D_Nyholm]

No, I would formulate a recipe for 5g batch, high gravity, then do the dilution calculations on my own. Ie. if a 5g batch of 1.080 wort creates 36 IBU's, I know when I dilute wort after cooling I will have 18 IBU's for resultant 10g batch. and 1.040 gravity.

Yeah, same result, just going about it a different way.

 

[tre9er]

I've decided to do a partigyle after reading this thread and doing some homework. My plan is to make a 2.5g. batch of an IIPA (pretty close to Yooper's Stone Ruination clone) and then a ~5g. batch of something similar to BierMuncher's SWMBO Slayer (a belgian blonde).

Thanks for the inspiration, guys!

 

[Horseballs]

Yeah, I think I'll end up doing 10 gallons of a mild, bitter or kolsch after consideration. That way I can have a few and not run out of bottles really quickly.