Getting bigger batches from smaller brew pots?

[ophillium]

I have a 7 gallon pot and have been wondering lately if it's possible to stretch out my 4 gallon batches into something larger -- my carboys look so sad sitting there half empty, and for all the effort I go to on brewday it would be nice to eek out a bit more bang for my buck.

Obviously brewing two batches and combining them in the carboy is a possibility, but it still requires the brewing of two separate batches.

So, with all that said, my question is: can I calculate my grain bill for a 6 gallon batch, brew a 4 gallons of that in the brewpot, and then add the last 2 gallons of water into the carboy?

Any insights or techniques would be very much appreciated.

 

[Bosh]

I go AG with an even smaller brew pot and do 5 gallon batches. How I do it:
-BIAB in an approx 5 gallon brew pot.
-Sparge in a bottling bucket.
-Split sparge+mash water between mash pot and stew pot.
-Boil hops in both at the same time.
-Put both pots in bathtub with cold water in it to cool.
-Pitch.

 

[ophillium]

I go AG with an even smaller brew pot and do 5 gallon batches. How I do it:
-BIAB in an approx 5 gallon brew pot.
-Sparge in a bottling bucket.
-Split sparge+mash water between mash pot and stew pot.
-Boil hops in both at the same time.
-Put both pots in bathtub with cold water in it to cool.
-Pitch.

Smart. Two questions: (1) what's your heat source? (i.e. stove, burner, etc). and (2) how do you calculate your grain bill? Are you estimating the efficiency of the sparge and averaging it out with your brewhouse efficiency?

I'm also brewing in a bag, using a "turkey deep-frying" kit for heat.

 

[Gnomebrewer]

I have a 7 gallon pot and have been wondering lately if it's possible to stretch out my 4 gallon batches into something larger -- my carboys look so sad sitting there half empty, and for all the effort I go to on brewday it would be nice to eek out a bit more bang for my buck.

Obviously brewing two batches and combining them in the carboy is a possibility, but it still requires the brewing of two separate batches.

So, with all that said, my question is: can I calculate my grain bill for a 6 gallon batch, brew a 4 gallons of that in the brewpot, and then add the last 2 gallons of water into the carboy?

Any insights or techniques would be very much appreciated.

Yes, you can....BUT
Your efficiency will be lower, because you aren't lautering as much sugar off the grain as you would with a full boil. Also, your extraction of alpha acids is lower because you're boiling at a higher gravity than with a full boil. It works better for lower gravity beers than for bigger beers.

 

[Gnomebrewer]

The other thing you could try is an anti-foaming agent, to reduce the break. You should be able to brew batches bigger than 5gals in a 7gal pot using anti-foam.

 

[cjbalough]

I know a lot of you frown on it for whatever your reasons, but you can always add a late addition of DME/LME.....and top up with water in the fermenter.

 

[Ramitt]

I know a lot of you frown on it for whatever your reasons, but you can always add a late addition of DME/LME.....and top up with water in the fermenter.

That is a pretty good option, I don't find late addition dme to effect taste when I have added a pound or 2. I have never added top off water, but I doubt it would make a huge difference.

Before I hadmy 16 gal kettle I often boiled the 3rd sparge on tbe stove and added it as my main kettle allowed. Worked fine, but carrying a couple gallons of just off boil wort around is sketchy.

 

[Patrick87]

The other thing you could try is an anti-foaming agent, to reduce the break. You should be able to brew batches bigger than 5gals in a 7gal pot using anti-foam.

+1

Fermcap-S is great. I was able to boil a lot more wort in my 7.5 gallon turkey fryer pot once I started using Fermcap. 5+ gallons is easily attainable once you don't have to worry about boil overs at every hop or DME addition.

 

[ophillium]

The other thing you could try is an anti-foaming agent, to reduce the break. You should be able to brew batches bigger than 5gals in a 7gal pot using anti-foam.

Interesting -- what's in it though? I'm a bit of a purist with my cooking, usually looking to do more with less.

I know a lot of you frown on it for whatever your reasons, but you can always add a late addition of DME/LME.....and top up with water in the fermenter.

Hrm. I'd prob brew a second batch before taking that route, for the same reason I'm apprehensive about anti-foaming agents.

 

[Bosh]

Smart. Two questions: (1) what's your heat source? (i.e. stove, burner, etc). and (2) how do you calculate your grain bill? Are you estimating the efficiency of the sparge and averaging it out with your brewhouse efficiency?

I'm also brewing in a bag, using a "turkey deep-frying" kit for heat.

Will post some more ideas later when not chasing the kids around but:
-Got a crappy electric stove that can just baaarely keep all my wort boiling even when I divide it into two pots and stick them non different burners.
-Just take a gravity reading of the final wort after I dump everything into the fermenter after cooling the wort in the bathtub. For calculating my grain bill I just assume I'll have a similar efficiency as last time.

 

[schokie]

Yes, you can....BUT
Your efficiency will be lower, because you aren't lautering as much sugar off the grain as you would with a full boil. Also, your extraction of alpha acids is lower because you're boiling at a higher gravity than with a full boil. It works better for lower gravity beers than for bigger beers.

The OP's suggestion is exactly what I do. I have a 10 gal brew pot and routinely do 10 gal batches. However, for the reasons you mentioned above, I only do moderate gravity brews that way (<~1.060ish). I am also limited by my 10gal mash tun. If I had a larger mash tun, or used extract, I could get a higher OG.

When I want to do a bigger beer like an IPA or Dubbel, I only make 5 gals.

The key to high efficiency and hop utilization is to have as close to a full boil as possible. Fermcap is magical. I can boil 9.5gals in my 10gal pot. The days of babysitting my boil are over!

 

[ophillium]

Yes, you can....BUT
Also, your extraction of alpha acids is lower because you're boiling at a higher gravity than with a full boil. It works better for lower gravity beers than for bigger beers.

Can you clarify what you mean here? Is it basically that you'd be boiling a concentrated wort (to be diluted by the sparge water), which lowers the efficiency of alpha acid extraction?

Also, where do alpha acids factor in for wort production? I've only ever heard talk of fermentable and non-fermentable sugar extraction.

Edit: You must be talking about hops. But then how does gravity fit into the picture?

 

[schokie]

Gravity is a factor in most hop utilization formulas. The two are inversely related. So as gravity increases, utilization decreases, requiring more hops for the same level of bitterness.

I will caveat that with the degree of importance of gravity in alpha acid utilization is debated. I believe Yooper claims it doesn't matter at all. I'll admit I haven't noticed that much of a difference. There probably is one, but not to a degree that my limited palate can discern.

My theory is that the higher the gravity, the greater the boil over, in general. So if there's a lot of hot break, you might loose some hops stuck to the side of the boil kettle. Maybe the reason I haven't noticed much difference across the various gravity levels is because I've always scraped that back into the boil and used Fermcap.

Go Fermcap!

 

[ophillium]

Gravity is a factor in most hop utilization formulas. The two are inversely related. So as gravity increases, utilization decreases, requiring more hops for the same level of bitterness.

I will caveat that with the degree of importance of gravity in alpha acid utilization is debated. I believe Yooper claims it doesn't matter at all. I'll admit I haven't noticed that much of a difference. There probably is one, but not to a degree that my limited palate can discern.

My theory is that the higher the gravity, the greater the boil over, in general. So if there's a lot of hot break, you might loose some hops stuck to the side of the boil kettle. Maybe the reason I haven't noticed much difference across the various gravity levels is because I've always scraped that back into the boil and used Fermcap.

Go Fermcap!

Thanks very much for this, schokie. Was I correct in inferring that you're brewing a more concentrated wort that will be diluted with the sparge water? I'm still uncertain how to plan a recipe that would include (say) 5 gallons of wort from the mash and X# gallons from the sparge. Also, would the sparge water need to be boiled out, or can one add it straight to the carboy? (related question: does boiling alter the chemistry of the wort, or is it just a means of eliminating excess water that was required for the mash?)

 

[schokie]

You are correct in your inferring.

Thanks very much for this, schokie. Was I correct in inferring that you're brewing a more concentrated wort that will be diluted with the sparge water? I'm still uncertain how to plan a recipe that would include (say) 5 gallons of wort from the mash and X# gallons from the sparge. Also, would the sparge water need to be boiled out, or can one add it straight to the carboy?

I'm not sure what you mean by sparge water. Sparge water is the extra water you use to rinse the grains prior to boiling. Sparge water is boiled. The water used to dilute the wort post-boil to ensure a specific amount in the fermenter is generally referred to as top-off water. It does not have to be boiled. Some OCD people will actually boil the top-off water, or filter it, reverse osmosis, etc. I just use plain old tap water. So far, so good!

The planning is actually quite straight forward. You just can't be afraid of fractions.

For example, dry extract normally is about 43 points per pound per gallon. So 1lb extract in five gallons is 45/1/5=9. That would be a gravity of 1.009. Obviously you want more than that, so start with your desired OG and work backwards. A 1.050 OG would require 50=43/X/5. Solve for X and you need 5.8lbs extract. Now is when you're happy you paid attention to algebra in high school. If you're using all grain, the math is the same, but assume 36 pppg instead of 43. It varies a bit depending on the type of grain, but using 36 as an average will get you close enough. Don't worry about efficiency for now. Change 5 gal to whatever size batch you want to do.

BTW, only barbarians refer to it as ppg. It is correctly called pppg. Moving on...

Now, decide how big your boil is going to be. While I can boil right up to the rim of my 10 gal kettle, that's a lot of water to lift. I normally plan on a 7.5-8.5 gal boil. If you're using extract, this part is easy. The amount of extract/grain is independent of your boil kettle volume. So in my 10 gal kettle I fill it up to about 7 gals with water, heat it up, add the calculated extract, boil, cool, and then evenly split it into 2x 5-gal fermenters. I then add top-off water to bring both fermenters up to the 5-gal mark. To be pure, they're actually 6.5gal fermenters, but I'm brewing 5 gal in each. Don't forget the krausen. The amount of top-off water isn't important. Neither is the boil volume. The only amounts that matter are the final volume into the fermenter and the amount of extract to get to my desired OG.

For all-grain, it's slightly more complicated, but the basic process is the same. I go through the math I mentioned above to calculate the amount of grain I need. I then multiply the grain lbs by 1.25 to calculate the quarts of water for the mash. 1.25 qt/lb is just an average mash density. Don't be afraid to go a bit higher, but I wouldn't go much lower. So 10lbs of grain would need 12.5 qts, or about 3+a bit gallons in the mash. So I take about 3 gallons of water, heat it to my desired mash temp, then dough in the grain. Once the mash is complete, I drain the water out into my brew kettle. I then add 4 gallons to the mash tun for a sparge (7gal boil-3gal mash). Drain that into the boil kettle and the rest is as described above. I actually also factor in mash tun deadspace and about 1/4 qt/lb of water for grain absorption.

If you're keeping track, you'll notice my process requires two kettles. I use my 10 gal kettle for the boil and I use a second 5 gal kettle to heat mash/sparge water. If you only have 1 kettle you can use the no-sparge method, but that will reduce your efficiency some.

(related question: does boiling alter the chemistry of the wort, or is it just a means of eliminating excess water that was required for the mash?)

Yes. It does both. The boil drives off volatile precursors for off flavors like DMS. 60 minutes isn't always required, but it will depend on the type of grain used. The tradition is a 60 minute boil, which is what I normally do, but there are a number of good recipes out there that use a shorter boil. With extract, even just a 15 min boil can be fine. It also concentrates the wort and reduces volume.

 

[NTexBrewer]

I have a 7 gallon pot and have been wondering lately if it's possible to stretch out my 4 gallon batches into something larger -- my carboys look so sad sitting there half empty, and for all the effort I go to on brewday it would be nice to eek out a bit more bang for my buck.

Obviously brewing two batches and combining them in the carboy is a possibility, but it still requires the brewing of two separate batches.

So, with all that said, my question is: can I calculate my grain bill for a 6 gallon batch, brew a 4 gallons of that in the brewpot, and then add the last 2 gallons of water into the carboy?

Any insights or techniques would be very much appreciated.

What you are describing is called High Gravity Brewing. I have never done it but I found this article that does a good job of explaining the technique.

http://byo.com/hops/item/237-blending-for-volume-techniques

Also since you plan to add your water to the fermenter you eliminate the oxidation problem the article talks about when diluting beer after fermentation is complete.

 

[chickypad]

No need to make it complicated - the answer is yes you just use the 6 gal grainbill then top off at the end, though as mentioned you will likely need to adjust for some lost efficiency. Another way to think of it that may help, if you want 6 gallons of a 1.050 beer but you are making it on a 4 gal system, you need:

50 x 6 = 300 pts / 4 = 75 pts, or 1.075

So do your calculations as if you were making 4 gals of a 1.075 beer. Hopefully you already know how to adjust your efficiency, etc. from prior experience. In Beersmith it's even easier, just put in the recipe for 6 gals but then input 2 gal of top off water. You'll still need to set your efficiency.

To give an example I sometimes make 5.25 batches on a 3 gal system, so end up topping off even a larger percentage than you are planning. I will often have 3 gal of a pretty high gravity wort like 1.090's or so, I find my efficiency drops off from the usual 78-80% to about 71-72%. YRMV

 

[ophillium]

No need to make it complicated - the answer is yes you just use the 6 gal grainbill then top off at the end, though as mentioned you will likely need to adjust for some lost efficiency. Another way to think of it that may help, if you want 6 gallons of a 1.050 beer but you are making it on a 4 gal system, you need:

50 x 6 = 300 pts / 4 = 75 pts, or 1.075

So do your calculations as if you were making 4 gals of a 1.075 beer. Hopefully you already know how to adjust your efficiency, etc. from prior experience. In Beersmith it's even easier, just put in the recipe for 6 gals but then input 2 gal of top off water. You'll still need to set your efficiency.

To give an example I sometimes make 5.25 batches on a 3 gal system, so end up topping off even a larger percentage than you are planning. I will often have 3 gal of a pretty high gravity wort like 1.090's or so, I find my efficiency drops off from the usual 78-80% to about 71-72%. YRMV

Thanks very much for this, chickypad. Thanks to this I've added an extra 1.5 gallons to each batch - easy peasy.