Expecting low O.G. should i up all grains to compensate?

[D_Nyholm]

I am brewing a 10 calling batch this weekend when I normally brew 5 gallons. I typically hit mid 70% efficiency with 5 gallon batches but the last time I brewed 10 gallons it was high 60s. Should I compensate by adding more base grains or should I up all the grains? I was thinking just the base grains as the specialty grains should get most of the flavor and color extracted but I'll just be missing some base sugars?

The reason my efficiency is lower on 10 gallons is because I brew in a 10 gallon pot and I have to add top off water after the boil so it powers my efficiency slightly. I need a bigger pot!

 

[NordeastBrewer77]

Do you use software? I'd say your best bet would be to take the original (5 gal) recipe, and scale it up to 10 gal with the lower (expected) eff. using the software. And I agree, we all need a bigger kettle man.

 

[Pratzie]

^^^ if u have brewing softwater do that... Otherwise upping the grainbill will help increase efficiency.

 

[NordeastBrewer77]

Kinda OT, kinda not.... I find that with bigger mashes in general, if I recirculate half (or the whole) volume of the mash (and sparge for that matter), you can bump the mash eff. a few points. Definitely not fool proof, but I learned this from a buddy the first time I did a ten gal batch. I'm assuming a batch sparge; recirculate mash, run wort, sparge, recirculate and run seconds. Might give ya a few extra points where it counts.

 

[gr8shandini]

I'm guessing your efficiency loss is from incomplete sparging due to the limited volume. It would take some interesting math to get it to work out, but what if you were to sparge as if you could do a full boil, and top off with the wort that wouldn't fit in the kettle instead of water?

 

[D_Nyholm]

I don't have a way to recirculate and I biab.

On my first 10 gallon, I mashed with about 6 gallons, and then dunk sparged with another 4 gallons and added that to the boil as I got more and more boil off. I only had to top off with another gallon or so, but still had 67% efficiency or so. I bet it would have been worse if I didn't dunk sparge.

I am making a Belgian wit so the yeast really makes a lot of the flavors. I am hoping that any decrease in maltiness will not be noticed as much. I was thinking of plugging the recipe into beersmith and then figuring out what I need to add to bring it up to the correct o g with a calculated efficiency of 67% or so. Insure do hate measuring out odd weights though!

 

[gr8shandini]

Ahhh. I didn't know you were talking BIAB. You can certainly increase the grain bill to make up for the low efficiency and the few extra bucks it'll cost are probably worth it versus coming up with a new process.

That said, I'm not a BIAB guy, but it seems that if you were to pour the sparge water over the bag instead of dunking you might be able to get a few more points out of it. Just be careful as 170 degree water will do a number on you if you spill (don't ask me how I know).

 

[DocScott]

Kinda OT, kinda not.... I find that with bigger mashes in general, if I recirculate half (or the whole) volume of the mash (and sparge for that matter), you can bump the mash eff. a few points. Definitely not fool proof, but I learned this from a buddy the first time I did a ten gal batch. I'm assuming a batch sparge; recirculate mash, run wort, sparge, recirculate and run seconds. Might give ya a few extra points where it counts.

Not to get back off topic, but I'm not sure this works...
Assuming you are getting extraction from all of the grain (read: not getting dough balls or having too much grain for the mash volume) then your mash system should come to an equilibrium. This means the solution (wort) has extracted the sugars from the grain so that they are equal in terms of concentration. If you recirculate the mash, it wouldn't increase the extraction anymore- theres no gradient to allow further extraction. The reason for sparging is that you are introducing water with no sugar concentration into the solution, which lowers the wort concentration and creates a gradient which drives sugars out of the grain, into the wort until a new steady state is achieved.

Back on topic...

 

[NordeastBrewer77]

I don't have a way to recirculate and I biab.

Ah, gotcha. Makes it harder to up the efficiency on a big mash. Do you mash in a spigoted kettle? If so, you can recirculate manually, run wort into another vessel and pour back into the mash. Do what with half to the whole volume. Also.... Since you bag, you can go with a very fine crush, which may help some. I did BIAB for a while (I actually still bag my mash in the tun for ease of sparge) and never was able to get really good eff. in larger mashes. The "dunk sparge" will help, but your best bet is to write the recipe for the lower eff. and use the extra malt to hit your OG.