Why Lower Effeciency With Big Beers?

[Drunkagain]

Just wondering why effeciency goes down when making a big AG beer?

 

[Bobby_M]

Water to grain ratio goes down so less rinsing occurs.

 

[shafferpilot]

You could keep the efficiency the same if you were willing to keep the water to grist ratio the same as your smaller brews. But that would mean hours and hours of boiling to get the volume back down to your batch size. It's easier and cheaper to assume a lower efficiency and use a couple more pounds of grain.

 

[slnies]

If you are really worried about grain waste, you could add even more grain, not much more though and collect the first wort for you original beer and then batch sparge and collect wort for a second beer. Party gyling is cool.

 

[ohiobrewtus]

In the last couple of big beers that I've done I mashed for 75 minutes and collected 13 gallons (11 gallon batches) and achieved 80% and 89% efficiency respectively. With 60 minute mashes I was lucky to hit 72%.

I have no scientific proof that the addtional mash time is the sole purpose fro this increase in efficiency, but I do know that the extended mash time is the only variable in my process that changed (intentionally anyway). I have yet to brew another big beer since I brewed these two, but I plan on sticking with 75 minutes mashes hoping to achieve similar results.

 

[Got Trub?]

You can also get incomplete conversion as product inhibition will occur once the sugar concentration gets high enough - the high sugar concentration impairs the enzymes ability to continue processing the starch.

GT

 

[Kaiser]

In the last couple of big beers that I've done I mashed for 75 minutes and collected 13 gallons (11 gallon batches) and achieved 80% and 89% efficiency respectively. With 60 minute mashes I was lucky to hit 72%.

batch sparging or fly sparging?

For batch sparging I elaborated on the efficiency limit here.

Kai

 

[drayman86]

Water to grain ratio goes down so less rinsing occurs.

This must be in reference to batch sparging. We don't see any efficiency drop between bigger and "smaller" beers when we fly sparge through out system. We just set the outflow rate from the mash tun at about 1 quart/minute, keep the sparge water temp. about 175f, and ensure there's about 2 inches of water above the grain bed. No sprinkling; just plop an inverted collander on top of the grain bed and trickle the water down onto the top of the thing. We simply run the sparge until we get about 12.5 gallons in the boil kettle and then boil for an hour.

Palmer has an article the Jan/Feb BYO, Advanced Brewing, which is an excellent treatment of sparging, best manifolds/bottoms, etc. Also the January 24th edition of Basic Brewing Radio has a Palmer interview covering similar subjects.

 

[Bobby_M]

I will buy the fact that fly sparging is less affected by total water to grain ratio but I find it doubtful that it is not affected at all. I could be wrong but I'd like other fly spargers to weigh in on it.

 

[drayman86]

I will buy the fact that fly sparging is less affected by total water to grain ratio but I find it doubtful that it is not affected at all.

No question there, certainly some effect. I'll have to measure total amount used next time I do a big beer, or anything.

 

[Bobby_M]

We also have to recognize the fact that the lowered efficiency is based on a fixed preboil volume. Sure you can keep sparging until you get all the sugar out of a larger bill but that requires longer and longer boil times. Diminishing returns keeps me at say a 90 minute boil no matter what.

 

[ajf]

I will buy the fact that fly sparging is less affected by total water to grain ratio but I find it doubtful that it is not affected at all. I could be wrong but I'd like other fly spargers to weigh in on it.

Yesterday, I brewed 10.5# Maris Otter, 1.5# Munich, and 0.25# Crystal 55
Collected 6.75g with a gravity of 1.060 into the kettle (my normal volume).

I did however do a 100 minute sparge, and the gravity of the runnings dropped to 1.008 right at the 6.75g mark.

According to my numbers 87% efficiency. 2 - 3% above normal.
W-e-i-g-h :rockin:

-a.

 

[Bobby_M]

That's basically what I get on a similar bill. 88% brewhouse.

 

[ajf]

That's 1.060 into the boiler. 1.074 into the fermenter

-a.

 

[Bombo80]

I didn't do too bad, this weekend. Did a monster Westy 12 clone. total grain bill of 20.45#, plus 1.25# candi sugars. The efficiency calculator on Tasytbrew, tells me I hit 72%. I had a 1.052 preboil reading (10 gallons), and a 1.108 OG, after a 3 hour boil !!!

All in all, not too bad, considering it was my first AG batch with my new MLT and Keggle.

Man, was it nice not having to worry about running out of room in my boiler. I can hardly wait for this one to be drinkable. It's funny what little things you learn, when doing something new, or in my case, using new equipment. The MLT worked out perfectly. I undershot my mashout temp, and had to do a decoction heating, to get it up to 170*, for mash out. It took three, one gallon draws, heated to 200*, to get it up to temp. Next time I'll have extra water ready to go, just in case. That really sucked.