All Grain brewing w/ reduced boil volume

[cd2448]

I have always understood that I can't do AG brewing because my boil volume is limited to 4 gallons, but a couple of weeks ago someone, I don't recall who, said that no, it's possible to do partial boil for AG brews, you just need to adjust grain amounts.

Now Beersmith has a "scale recipe" feature which allows this, but it's coming out with a lot less grain than I would expect - it's reduced approx in line with the boil volume, but that doesn't really make sense to me. Has anyone successfully followed this appoach or should I just resign myself to having to use extract?

 

[Trappist Artist]

If by reduced boil volume you mean that you just make 3 gallons instead of 5 gallons all-grain should work just fine. But, if you were intending on having a concentrated boil and then diluting to 5 gallons (as many extract brewers do) this may present a problem.

But, if you are willing to spare some efficiency you may just be able to pack a whole ton of grain into your mash tun and get pretty concentrated wort. I think the most concentrated wort that I've been able to get out of my MLT was about1.1 -- But, this was from almost 30 lbs of grain for a 5 gallon batch.

 

[cd2448]

Yes, I mean boiling say 4 gallons then diluting after the boil. The wort itself wouldn't be any more concentrated than it is for an extract brew at the point when you dilute it, but I was expecting that my efficiency would be awful because I won't be able to run so many batch sparges, and now I try the scaling thing again and put in like 50% for efficiency, the grain bill does increase so it's kind of making sense.

 

[Chello]

What i do is use Beersmith to scale a 5gal AG recipe down to 3gal. Then i manually adjust the batch size back to 5gal and then add DME until the OG is back to where it needs to be.

Sure it's not completely all grain, but it will reduce your costs and also give you good mashing practice while you can't do full boils.

 

[cd2448]

hmmm... sort of like a big partial mash approach? i'm doing PMs now, and it's really improved the beer. i'm at least going to get a larger mash tun so at least i can get more of my fermentables from grain instead of DME/LME. i think it was just wondering if it's possible to take this to the extreme and get all my fermentables from grain whilst still limited by boil size.

 

[Special Ed]

I've been considering this also, but for a slightly different reason. It is the same concept just at a different volume.

My thought is to adjust a pale ale or blonde recipe to a much higher gravity (like 1.065-70) @ 6 gallons. After it's boiled and cooled to fermentation temp, split it into 2 carboys (3 gallons each) then top each off with 2 gallons of water (resulting in 1.038-1.042), pitch same or maybe 2 different yeasts.

Pro's:
no airation needed like back in the extract partial boil days.
requires smaller equipment than a 10 gallon full boil.
likely a somewhat quicker brew day.

Con's:
requires more hops due to reduced extraction from the higher gravity wort.
possibly reduced efficiency due to less sparge water?

Does anyone see any holes in this idea?

 

[cd2448]

i knew this was already covered and i finally found a search to pull it up:

https://www.homebrewtalk.com/showthread.php?t=47285

looks like i might as well stick with the partial mashes for now and start plotting my AG set up for full-sized boils for my 5gallon batches.

 

[reshp1]

I'm limited by my kettle size too. What I did was to use the 5gal grain bill as is, and use 2 pots (I have a 5 gal and a 2 gal) to boil the approximately 5.5-6 gals collected down to ~4gal, or whatever you can comfortably boil. It'll take a little longer and is less energy efficient but it works. You have to split your bittering hops, which could need some adjusting because the wort in the two pots will be different gravities, but I didn't worry about it. Once I got it into a single pot, I proceeded as if doing an extract, partial boil. Once I had the wort cooled and in the fermenter, I diluted with water until I got the right OG, which worked out to be right around 5 gals.

 

[flowerysong]

Interesting idea. My first thought would be to do no-sparge brewing to get the requisite high gravity and low volume for the partial boil.

So, I'll quickly run through what I would do to reformulate my most recent batch (a brown porter) as a no-sparge partial-boil all-grain.

A five gallon batch and our target OG is 1.051. Let's see...
Mash thickness of 1.25 qts/lb results in an OG reading of approximately 1.080 for first runnings. We need 4 gallons of 1.064 wort to hit our final gravity reading, so we need about 3.2 (call it 3.25) gallons of 1.080 wort, which will be diluted in our kettle to make up our initial boil volume. So, how much grain do we need? Hmm, 1.25 qts/lb, 0.15 qts/lb grain absorption...let's say 12 lbs. Scale the recipe, and we have the following grain bill:

9 lb 13 oz Golden Promise Pale
10 oz American Chocolate Malt
10 oz Crystal Malt 60L
15 oz English Brown Malt

Mash in with 4.25 gallons. Draw off 3.25 gallons of first runnings and check the gravity. If it's low, try to get as much extra sugar out as we can--collect any remaining runnings and then, since I'm not a huge fan of no-sparge anyway, go ahead and throw 3 quarts or so of sparge water in. If it's really low, swear loudly and decide never again will you listen to the idiot that told you this would work, then make a small beer or bump it up with malt extract. If it's on or high, dilute to 4 gallons and proceed with the boil.

Hop utilization will be low, so bump up the hops slightly. Amounts are just a wild guess, as A) I don't know how this turned out with my original amounts and B) I can't be arsed to do the utilization math.

1.5 oz Yakima Golding (5.0%) - added during boil, boiled 90.0 min
1 oz Yakima Golding (5.0%) - added during boil, boiled 30.0 min
1 oz Fuggle (4.8%) - added during boil, boiled 5.0 min

Wait, with the smaller volume we don't want to do a 90 minute boil. Bump that first hop addition to 60 minutes.

Since we don't need to reduce the volume, I'd probably add water every fifteen minutes to replace the boil-off and maintain a steady-state volume of 4 gallons.

Boil, chill, put it in the fermenter, top up to five gallons, and pitch your yeast.

 

[shafferpilot]

Since we don't need to reduce the volume, I'd probably add water every fifteen minutes to replace the boil-off and maintain a steady-state volume of 4 gallons.

Why not continue sparging the mash instead using water to maintain volume? Just be careful of boil-overs when you add.

I think this idea will work well, the efficiency will be $hit, but if you buy a big bag of your favorite base malt, I think you'll still save money over DME/LME

 

[cd2448]

@shafferpilot

that occured to me, too. just keep sparging, and top up the boil pot with more run-off from the mash.

but then i thought, what about split boiling? what if i boil 4gallons in one pot and 2.5 gallons in another (might need to boil 4+3 because with two boils i'll have more evaporation)? would the approach be to put all the hops in the main pot? or try and split the hops between the two boils? then get everything into one pot +immersion chiller to get it down to pitching temp - proceed as normal with fermentation.

anyone else do a split boil?

 

[flowerysong]

Why not continue sparging the mash instead using water to maintain volume? Just be careful of boil-overs when you add.

Well, I was assuming that we had hit our target gravity already and didn't need to add any more sugars. If it came in low, it would certainly be an option to continue sparging, but I'm not sure how much more we can get out. Plus, see below...

I think this idea will work well, the efficiency will be $hit, but if you buy a big bag of your favorite base malt, I think you'll still save money over DME/LME

Especially if rather than not sparging at all and leaving all those sugars behind, we do parti-gyle brewing and make another beer. We'll try for an English Mild.

While the first batch is boiling, allow the mash to cool 145F (try to reach this point when there are 20 to 30 minutes of the first boil remaining) and add:
1 lb 8 oz Golden Promise Pale
8 oz Crystal Malt 60L

Add an additional infusion-4.25 gallons of water @160F, for a target mash temperature of 155F. Mash until the first batch is cooled and in primary. We're shooting for our second runnings to come in around 1.045, but slightly lower or higher is okay. If they're at or below 1.040, drop the batch size to 4.25 gallons or supplement with malt extract.

Draw off four gallons, boil for 45 minutes. Hop schedule:
1 oz Fuggle (4.8%) - added during boil, boiled 45.0 min
1 oz Fuggle (4.8%) - added during boil, boiled 15.0 min

Pitch Nottingham or another English ale yeast.

I'm tempted to try this and see how it turns out and how realistic my numbers are.

 

[shafferpilot]

I like that ^ idea too

 

[shafferpilot]

@shafferpilot

that occured to me, too. just keep sparging, and top up the boil pot with more run-off from the mash.

but then i thought, what about split boiling? what if i boil 4gallons in one pot and 2.5 gallons in another (might need to boil 4+3 because with two boils i'll have more evaporation)? would the approach be to put all the hops in the main pot? or try and split the hops between the two boils? then get everything into one pot +immersion chiller to get it down to pitching temp - proceed as normal with fermentation.

anyone else do a split boil?

I've read of some people doing split boil and splitting the hops, but I don't think it's necessary so long as you aren't trying to do a IIPA or a IIIPA. The gravity of the wort determines the IBU's. Consider when doin a partial boil that the reduced volume does not cause the problem with hop utilization, the increased SG is the problem. There is a point where the volume being extremely low will effect hop utilization, but it would have to be really low volume before that was a problem. With a split boil, the SG is not higher, so it seems to me that putting the hops in the bigger pot only will work fine.

 

[Bobby_M]

Yeah, here's an idea. Take your first runnings and your first batch sparge runnings and put those in the biggest pot you have. Then runoff your second batch sparge runnings into your next biggest pot. Use this wort as your bittering because the gravity is very low in comparison, you'll get plenty of utilization. Once it's blended back in, it will be all good.

 

[cd2448]

Thanks Bobby. I'm so tempted to give this a try. Would I need to modify hop amounts or should I just say "gosh darn it" and throw in normal hop amounts for the recipe into the smaller pot?

But then... if I'm not getting hop util in my large pot - why am I boiling it at all (over and above 15 mins to kill beasties)? Is it to concentrate the wort?

 

[Bobby_M]

Actually all grain wort has all kinds of "stuff" in it that you want to drive off like DMS precursors and it also helps break down the proteins reducing chill haze. I'm sure I'm missing other reasons. If you're using Pils malt in particular, 90 minute boils are even recommended.

On the hop quantity, I think a reduced volume in lowered gravity will pull about the same IBUs as a full boil of moderate gravity. That's my way of saying, it's probably close enough to use the same amount of hops as if it were a full boil.

 

[cd2448]

thanks for the input guys.