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Sparge time vs. Efficiency

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Re: Sparge time vs. Efficiency

Posted: Mon Sep 05, 2011 2:19 pm
by Thirsty Boy
This low efficiency = better beer stuff is just complete bullshit. A well designed lauter tun and and properly conducted mash and lauter should be yeilding in the order of 90% efficiency, and if it does - thats a good thing not a bad thing.

High efficiency isn't bad... Oversparging is bad, if you get your high efficiency without oversparging, then there is nothing, absolutely nothing wrong with it.

If your system isn't well designed and/or your technique is bad - you will get poor efficiency, and if you then flog it up to high levels by sparging more aggressively, thats where the quality issues lie.

I sit in a room all day long at work, and i watch live graphs of run-off gravity/ph/tint etc scrolling as 20 brews a day go through our system. You can see the run-off gravity drop as a sparge proceeds, you can see it bottom out as the useful part of sparging reaches its end and and its essentially just water coming through, you can see the gravity suddenly & sharply rise as the polyphenols and other rubbish start to come through. With a iittle experience you dont even need the graphs, you go downstairs and watch the siteglass on the outlet of the lauter grant and you can see it... It gets lighter and lighter in colour, then it stops being clear and amber and changes to a cloudy yellow green murk. Thats the bottom. Guess where you cut the run-off?

And if you cut the runoff before the muck comes through, you dont have quality implications.

Now fair enough, at home you dont have live monitoring and graphs to tell you exactly when to cut your gravity... But then again at work we are getting efficiency in the 95% range and cut-off gravities of 1-2 plato. At home you build in some safety and cut off at 2-3plato and your efficiency will be lower. Great, sensible, thats what you should do. Someone earlier said they taste their wort and it goes from sweet to watery to husky.... Cut it off before the husky point, establish what gravity that happens at and stop a little before. Thats all sensible - but if your system is well made, then you're still going to be getting efficiency in the high 80s or near.

So the idea of cutting off at a point where your mash/lauter efficiency was at 75% is either an admission that your system isn't all that good, you are talking to someone who you suspect has a system isn't all that good - or its just an absolutely over the top safety margin. Its the brewing equivalent of always driving at 40 in a 60 zone. Sure - you're never, ever going to lose control and drive into a telegraph pole, but then again, its not like going at 55 is exactly reckless driving either.

So - if choking your efficiency down to 75 makes you feel better, thats fine, its certainly going to make sure you never experience issues from over sparging. But thats a massivey different thing to thinking that somehow getting a good solid high efficiency is inherrently a bad thing for beer quality. It isn't.

Oh, and if you do decide you want to be quite that cautious - then you need to remember that the object of the game isn't actually to reduce your efficiency... The object is to change your process to avoid any hint of the possible detrimental effects of excessive sparging. So you reduce your sparge, thats the goal - reduced efficiency is simply the result of that step.

So - if you crush your grain more coarsely and that reduces you efficiency. Yu are stil sparging just as much and you have done nothing to address the actual cause of the quality issues you are trying to avoid. You're just throwing money in the bin for nothing.

If you sparge more quickly and this reduces your efficiency - not only are you still sparging just as much and failing to address the actual issue, you are also making it more likely that the fast sparge will expose any design issues in your lauter tun and oversparge sections of your grain bed. So you are not only failing to address the issue that you are trying to address, you are throwing your money in the bin and potentially making things worse.

What you need to do is just crush, mash and lauter in the manner you have spent so much time and effort learning is the "optimum" way to do it. Make it so that if you wanted to, you could easily get 90% efficiency.... Then all you do is stop collecting your wort earlier. Leave behind extract that you could get if you wanted, and in the process leave behind all the bad stuff you belive you might get if you tried to get more. You've used more grain (because your efficiency is lower) so all you're doing is collecting the same amount of extract, in a smaller amount of stronger wort that you believe is of "higher quality". You get your volume by diluting.

Me, I get about 89% efficiency on my home system using what i think is a genuinely high quality process & the only significant change i can envisage happening to my beer by me deliberatly aiming for a lower efficiency, is that it would cost me more to make.

Re: Sparge time vs. Efficiency

Posted: Mon Sep 05, 2011 5:27 pm
by dmtaylor
I disagree.

I'm a Dennybrew-style batch sparger. And for a while, I was getting average efficiency of about 90%. As a batch sparger, I don't see much chance that I could be "oversparging". Might depend on your definition of "oversparge", but I'm sure the second runnings coming out of that cooler mash tun are not as watered down as could be if I were a fly sparger.

Yet when I brewed a Vienna lager 2 years ago, with zero off-flavors, and an efficiency of 94%, the flavors in the final beer just did not seem bright enough to me. I of course expected the Vienna malt character to pop-pop-pop, yet what I got was: okay, yeah it tastes like Vienna malt, but it's just sort of thin and needs more oomph. (Perhaps more salt additions were in order?) This was confirmed in BJCP competition, with constructive comments like: "flavor lacks complexity and could be more malty". And yet I scored a 36 and got a 2nd place ribbon. So... what gives?

As you may know, my theory goes that if I'd crushed the malt a little less, I would have had to use more malt in the mash tun to match the loss in efficiency, which could have resulted in a higher concentration of "malt stuff" in the wort, which ultimately could, in theory, result in a more pleasing tasting beer. In other words, if you like a lot of peanutty taste on your PB&J sandwich, don't spead the peanut butter too fucking thin!!!! This was not a bad beer in any way, other than I just wished it was just a little more malty.

So...... would lower efficiency have improved malty flavor? The jury's still out. More experiments are necessary, and I haven't gotten around to them yet. This might be a great one for James Spencer and Company. Can't say they'd resolve the issue once and for all, but 17 heads are better than 1 or 2.


Re: Sparge time vs. Efficiency

Posted: Tue Sep 06, 2011 6:15 am
by Thirsty Boy
I see your point, but i think it relys somewhat on something that I think is a bit of a homebrewer misconception. Although its one that applies mostly to continuous sparging, so it may or may not be applicable to batch sparging.

Some homebrewers seem to think that when you are extracting sugars from a mash, that somehow this happens seperately or at a significantly diffent rate to extracting flavour and colour compunds. That if you "keep sparging all you are getting is sugar, not flavour" or words to that effect. Why on earth would that be so?

If you crush less finely, you get lower efficiency because the liquid cant access all the malt in the tun (in the time you give it) and you need to add more malt. Now if for some reason all the maltiness in malt was on the outside, OK, that theory might be reasonable - but its not... The crushed insides of malt grains taste plenty malty, if you crush coarsley and cant get at them... You leave that maltiness behind.

If the flavour compunds were rinsed out earlier in the sparge (or in the first batch) then the sugars followed later it might work - but they arent. I've done a number of experiments comparing the relative rate of change in extract and colour compounds (because they are easy to measure and flavour compounds not so much) as a continuous sparge proceeds - and they drop off at about the same rate. If you leave behind an extra 10% - you a leaving behind an extra 10% of everything, including your maltiness.

Now, dont get me wrong, I'm not saying that what you experienced didn't happen. If you make a change in your process and it makes your beer taste better, who gives a rats behind what any theory might be - its worked and thats all that matters. I'm also not saying that Jamil or Tasty are wrong, same thing, they have a feature in their process and it seems to make their beer taste better. Awesome, who could argue with that?

In your case, you changed the way you crush your malt and like the results (or visa versa). But your beer isn't better because you "lowered your efficiency", your beer is better because you changed the way you crush your malt. Lower efficiency is just a side effect of the change in your process, but its what people seem to latch onto. Suddenly lower efficiency itself is what made things better... And ipso facto, of course that means that any time you get high efficiency that "must" be bad - when its not.

Its that notion - that efficiency, in and of itself is somehow a quality issue that I have a problem with. You optimise your process to make the sort of beer you want to make, and then when you are making the beer you like... You look and see what efficiency you are getting. If its high, you have a bonus not a problem.

Re: Sparge time vs. Efficiency

Posted: Tue Sep 06, 2011 7:07 am
by dmtaylor
I still disagree, and here's why. Let's talk partigyle. There are no doubt infinite methods of partigyling but I'll describe one that should work well for experimentation purposes. Treat it like a batch sparge, where the first runnings is for the first beer and the sparge is for the second beer. Now, before brewing the rest of the way, measure the gravity of your first runnings (the first wort), and take that second runnings and boil it down to precisely the same gravity as the first one. So you're basically starting with identical gravity worts, but the second one will be lower volume because it needed to be concentrated down to match the first, so when you brew it you'll need to adjust the amount of hops used, etc. to make everything else match up. So when you're all finished, you should have two identical beers, the only difference being that the second beer is made from second runnings, and there's less of it (less volume). So, in accordance with your theory, there's plenty of flavor compounds in that second beer, right -- even identical to the first?

Experience tells me to doubt that theory very much. While I've never tried this exact experiment, when I've partigyled in the past, I've found the second beer to be utterly lifeless compared to the one made from the first runnings. People out there do no-sparge batches for the same reasons -- it just plain tastes better, and efficiency be damned because it doesn't mean anything if you can make better beer by purposely accepting a crap efficiency.

Perhaps we should just agree to disagree. What we really need is the experience to say without a doubt which theory is correct. Truthfully, right now I don't think either of us have legs to stand on. But of course I still think I'm right because that's the kind of guy I am. :mrgreen:

Re: Sparge time vs. Efficiency

Posted: Tue Sep 06, 2011 9:32 am
by Thirsty Boy
An interesting idea for an experiement, and one which i will most probably try. I'd rather find out if I'm wrong. Although, rather than boil down the weak wort to match the strong one, you'd be better off diluting the strong wort. that way you aren't introducing a whole new set of flavours derived from an extended boil. Faster too, because you can do it on a small scale and taste the worts at pre-boil, any significant difference should be apparent there. Reduces possible variables from the boil-cool-ferment-package stages too.

We will have to disagree i guess - because i've done probably a hundred no sparge brews, its simply the way i used to brew - and i dont find that my beers now that i am fly sparging and getting 90%, are any less flavoursome than they used to be. So our experiences of this stuff are simply different.

I'll drop you a note if/when i get around to trying out that experiment. I'll get someone without a pre-formed opinion on the matter to double up on the tasting. Maybe some blind tests at my brew club meeting.

Cheers TB

Re: Sparge time vs. Efficiency

Posted: Tue Sep 06, 2011 10:01 am
by dmtaylor
Ditto -- I can run the experiment also on my end and get some unbiased help for the tasting, although I suspect it may be some time (weeks? months?) before I get around to it. I agree with the proposal to water down the first half, although I'll admit I do not like the idea of watering anything down! But it should indeed be a cleaner and simpler method.

Cool. :jnj

Re: Sparge time vs. Efficiency

Posted: Tue Sep 06, 2011 11:15 pm
by bcmaui
Very interesting discussion going on.

One thing that I noticed is glossed over that is just as important is mash time.

You can sparge faster or slower,you can crush finer or coarser, but you also have to throw into the mix the conversion time in the tun.

There is no one answer, it is a matter of fining a happy balance between many variables.

Re: Sparge time vs. Efficiency

Posted: Wed Sep 07, 2011 7:55 am
by dmtaylor
I think I can safely say that within reason, mash time is not a factor. If you only mash for 10 minutes, yeah, you'll likely have a problem with conversion efficiency. But I typically only mash for 40 minutes -- yes, 40 minutes usually, although sometimes 60 -- and I was still seeing average efficiencies of 90+%. So, like I say: within reason, mash time isn't a factor at all. I mean, maybe a 60-minute mash gets me one additional percentage point efficiency? Yeah, not a factor at all.

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