First AG - not enough volume!

Okay - it's not as bad as the title sounds, but I am looking for some advice for my next AG brew with regard to volume of the boil/size of the kettle. I brewed a fairly big beer for my firt AG attempt - Nugget Nectar clone with 14 lbs grain bill (FG target of 1.075). I mashed in a cooler and batch sparged. I collected 4 gal first runnings from 5.5 gal strike water volume, and added a little over 3 gal to collect just over 7 gal pre-boil volume of wort in my 8-gal kettle. I used ProMash to do my calculations, and figured on about 17% per hour evaporation rate (which turned out to be low) for a 60-minute boil. Turned out my evap rate is more like 21% - I wound up with about 5.5 gal in the kettle at flame out. I chilled with an immersion chiller and transferred. I barely made the 5-gal mark, and that was with dumping all the sludge into the fermenter (which I had whirlpooled to avoid - so much for that). I ended up topping off the batch with almost 1/2 gal of water so that I don't wind up with 4 gal of beer. Needless to say, by then my SG readings were tossed out the window since I was just trying to salvage my beer. It's happily bubbling away in the fermenter now.

After that lengthy prelude - what do you guys do to avoid this problem? I can guess that increasing the pre-boil volume to about 7.75 gal will allow me to boil off at 21% and wind up with 6 gal, and figure on losing about 1/2 gal to the trub. Of course, I can't do that in my 8-gal kettle. What size kettle do you AG brewers use for 5-gal batches of bigger beers? Do I need to upgrade to a 10-gal pot? Am I missing something? I appreciate any feedback - thanks!

First of all you set your recipe for 75% efficiency. With a single batch sparge that you have used (one pour of sparge water) you will get ~55-62% efficiency. Start doing your batch sparge with two pours of sparge water and your efficiency should go up to about ~60-65%. Then you want to adjust your recipes to down to 65% AND YOU GOOD TO GO! Happy brewing Beerballs

You also might want to throttle back that NASA booster you must be using to boil with.
Even with my SQ-14 wide open, I am at only about 13% in a keggle. You only need a bit of roll in the boil. You don't necessarily need flames lapping the ceiling.

bull8042 said:

You also might want to throttle back that NASA booster you must be using to boil with.
Even with my SQ-14 wide open, I am at only about 13% in a keggle. You only need a bit of roll in the boil. You don't necessarily need flames lapping the ceiling.

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This, and did you boil outside in the cold? In the Spring/Summer, your boil off will be significantly less.

My last AG in the cold, I kept my spare boiling water from the Mash nice and warm in case I over-evaporated. I did, and added some extra water for the last 15 minutes in order to hit my volume.

Scooby Brew - I appreciate the info on efficiency, but honestly I'm not too concerned about my efficiency unless there's something I'm missing on how that impacts my boil volume. If I am more efficient, I just hit my gravity and volume with less grain, right? I might have done this batch no-sparge, but for some reason I didn't feel like heating my strike water in 2 kettles. Might try no-sparge next time.

Yeah - boiled in the garage - probably about 35-40 deg F ambient temp. I guess I should throttle back a bit on the propane, but I remembered reading that a good vigorous boil is preferable to a low boil. Not sure why - 212 is 212, right?

If its boiling, you're good to go. No need for an extremely vigorous boil so next time hold off a bit.

You also don't need to concern yourself over efficiency issues with single batch sparging. I typically get between 75 and 80% with the same process and have never had lower than 70.

Megapots have very high evaporation rates - in fact most kettles that are very wide, having greater surface area, have more evaporation. I target 20% on my 8 gallon and it works well. To me, it seems your problem is with needing to get 5 gallons. Personally, I don't worry if I'm short on volume, because it usually means my wort is more concentrated, which means I can dilute in the fermenter. I check gravities with my hydrometer during all parts of the process, because I care more about getting the right starting gravity, which will correspond to the right level of bitterness for the recipe. Diluting like crazy for the sake of getting 5.5 gallons is silly, especially if you're going from 1.070 to 1.040. So what if you get a few bottles less than normal?

in my keggle, with the lid half-cokked, i have less than .5 gallon boiloff in 60 mins. and it's a moderate rolling seas in there!

sonetlumiere85 said:

Megapots have very high evaporation rates - in fact most kettles that are very wide, having greater surface area, have more evaporation. I target 20% on my 8 gallon and it works well. To me, it seems your problem is with needing to get 5 gallons. Personally, I don't worry if I'm short on volume, because it usually means my wort is more concentrated, which means I can dilute in the fermenter. I check gravities with my hydrometer during all parts of the process, because I care more about getting the right starting gravity, which will correspond to the right level of bitterness for the recipe. Diluting like crazy for the sake of getting 5.5 gallons is silly, especially if you're going from 1.070 to 1.040. So what if you get a few bottles less than normal?

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This is rite on with my experience as well. Work on hitting you O.G. and don't worry about the volume, it will be what it be. Just for the record I never get below 70% eff with single batch sparge either

What you're saying about not worrying too much ablout volume makes perfect sense - I guess I needed someone (or a couple people) to say that to me. I'd rather have 4 gallons of good beer than 5 gallons of thin crappy beer. I'll take all your advice, turn down the heat, focus on hitting my gravity, and let the vollume end up being whatever it is. I won't rush out to buy a new pot.

As an aside, I had my first blowoff with this batch! Went to check on it this morning before leaving for work and the airlock was full of yeasty wort, the little cap on top was nowhere to be found, and there was krauzen on the ceiling! I guess it's time to buy a blowoff hose. I told my wife if she hears an explosion in the basement, don't go down there...

BeerBalls said:

What you're saying about not worrying too much ablout volume makes perfect sense - I guess I needed someone (or a couple people) to say that to me. I'd rather have 4 gallons of good beer than 5 gallons of thin crappy beer.

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Actually, I don't think that's the point about volume. The point is that you did get a finite, measurable amount of sugars from your grain. It doesn't matter if you don't boil it at all, or if you boil it down to a quart of syrup - it will still all be there. If you got your desired amount of sugar, but over-boiled your wort, you can just add water to get back to the SG you wanted.

Now, if your efficiency was low, and you have to boil more water off to get to the SG you want, that's a whole 'nother story. Then, yes, better to go to 4 gallons and get what you wanted than 5 gallons of pig swill.

BeerBalls said:

I chilled with an immersion chiller and transferred. I barely made the 5-gal mark, and that was with dumping all the sludge into the fermenter (which I had whirlpooled to avoid - so much for that). I ended up topping off the batch with almost 1/2 gal of water so that I don't wind up with 4 gal of beer.

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Did you figure in cooling loss? Four percent is almost a third of a gallon right there. I'm sure Promash figures this in? Were you able to measure a SG at ANY point? Were you close?

BeerBalls said:

What size kettle do you AG brewers use for 5-gal batches of bigger beers? Do I need to upgrade to a 10-gal pot? Am I missing something? I appreciate any feedback - thanks!

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I boil in a keggle, and had to adjust my calculations for around 20% boil-off also. This was a big difference from my previous 32 qt turkey pot....more open area for evaporation. I would say get the biggest boil kettle you can get. I have no problems with 5 gallon batches in a keggle, but with bigger beers and/or 10 gallon batches, it may be too small ( I do no-sparge). A rule of thumb is a BK twice the volume of the batch. Should work in nearly every circumstance.

DNW said:

Actually, I don't think that's the point about volume. The point is that you did get a finite, measurable amount of sugars from your grain. It doesn't matter if you don't boil it at all, or if you boil it down to a quart of syrup - it will still all be there. If you got your desired amount of sugar, but over-boiled your wort, you can just add water to get back to the SG you wanted.

Now, if your efficiency was low, and you have to boil more water off to get to the SG you want, that's a whole 'nother story. Then, yes, better to go to 4 gallons and get what you wanted than 5 gallons of pig swill.

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Yes, exactly. Say you were shooting for 5.5 gal @ an OG of 1.056 in the fermenter and instead you end up with 5 gal at 1.062 you can add 1/2 gal of water and end up at 1.056. Now on the other hand say you end up with 5 gal at 1.056 in the fermenter you could just let it ride and end up with a little less beer but at the OG that you were shooting for. Hope this helps

I electric boil in a keggle and i lose a lot to evaporation. Since my rig is in my basement I have a temporary 500cfm hood set up to pull all that moisture outside(nobody wants a moist basement(unless you make cheese ). I lose at a minimum 20% due to evap and don't forget about moisture loss from your hops. Right now my boils are at about 204-207 degreed F.
When boil is over I just top up with water from my HLT until I hit my target volume while cooling. I don't bother to take a sample for a gravity reading until I'm down near pitching temp. For example I shoot for 7 gallons in the kettle to end up with 5.5-6 gallons. On my 10 gallon porter with 1lb of hops, I end ed up at 9gallons from 12 gallons pre boil.

Over time you'll get a feel for your rig and end up right where you want.

Flananuts

I just draw off a little extra wort and add that to the kettle if it gets low. The extra can always be boiled down for starters.

david_42 said:

I just draw off a little extra wort and add that to the kettle if it gets low. The extra can always be boiled down for starters.

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I never thought about this but it's a damn good idea.

That is a great idea - I actually had at least 1/2 gallon extra (too much sparge water) and dumped it. I'll save it next time.

Boil off rate as a percentage value is just stupid. I have no idea why beersmith implemented that way. I boil off 1.5 gallons per hour in the winter and about 1.25 in the summer. It doesn't matter if it's a 5 or 10 gallon batch.

Bobby_M said:

I boil off 1.5 gallons per hour in the winter and about 1.25 in the summer. It doesn't matter if it's a 5 or 10 gallon batch.

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I was going to say that is still a percentage of your initial volume, but NM. I see your point. I don't have it here, but can't you manually input your boil-off in Beersmith?

Reelale said:

I was going to say that is still a percentage of your initial volume, but NM. I see your point. I don't have it here, but can't you manually input your boil-off in Beersmith?

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Yeah, just unclick the "calculate boil volume" check box.


I agree that % is a poor way to implement it, but its really not a big deal.

can AG brewing be accomplished sucessfully with a 5.5g boil and then a top off?

bushmanj said:

can AG brewing be accomplished sucessfully with a 5.5g boil and then a top off?

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it can be accomplished, but will negatively effect efficiency

other than efficiency will there be any other negetive effects? i feel like with a long mash and a batch sparge the effciency cannot be effected that negitively

It will be effected, be sure of that. There is no other negative effect though.

will a different mash techneque be useful or should i just up the grain bill to bridge the gap?

Yeah, you can just up the grain bill a little to make up for lower eff. There are other sparge methods like fly sparge but I have not tried it, I'm pretty happy with batch sparge at this point so I have not felt the need too. Some people do prefer fly over batch sparge though and I hear that eff is a little better that with batch. I think the key is to figure out your system and what works for you and go with it. Then experiment with other methods if you feel the need to. I think the biggest boost in eff comes from having a good crush, like I said earlier I batch sparge and never get below 70% as long as I have a good crush. I have been thinking about trying a false bottom in my mash tun, that would give me the ability to fly sparge in the future if I ever want to give it a try.

ok a question I have after reading this.

If you are boiling at say 75% power(propane burner)and then notice you need to boil off some Extra to get in your SG. Will cranking up to 100% power make you evaporate more in than at 75%?

Bobby_M said:

It will be effected, be sure of that. There is no other negative effect though.

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Well, hes going to get more carmelization, lower hop utilization, etc. Similar to not doing a full boil with extract.

Conodor said:

ok a question I have after reading this.

If you are boiling at say 75% power(propane burner)and then notice you need to boil off some Extra to get in your SG. Will cranking up to 100% power make you evaporate more in than at 75%?

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Yes. The more heat you are able to get into the boiling wort the more heat it has to get rid of and it does that by changing water into steam so your boil off will be more the harder you boil.

Ok thanks. I wanted to verify I wasn't just thowing propane into the air.