Mash out effects on efficiency?

I've read multiple times on this forum where people state that they've increased their efficiency by mashing out and I have a hard time wrapping my head around that.

As I understand it, a mash out is to halt the enzymatic activity from the mash. That's it. You're basically raising the grainbed temp by whatever means to around 168-170 to halt the enzymes from further converting starches to sugars. That halt effectively "cements" in your mash profile.

If that is true then I would think that theoretically, if anything, mashing out could potentially reduce your efficiency since you're cutting off the conversion when it could have gone on further while lautering/sparging/etc. until the wort is brought to a boil.

Personally I've never mashed out however a few of my latest beers have fermented to a lower FG than expected and I figured mashing out before lautering would be a good way to correct this issue. (In case it matters, I mash in a 10gal cylindrical cooler and do 2 equal batch sparges after lautering first runnings.)

Thoughts?

I wonder if, when mashing out, stirring and letting it sit 5 to 10 minutes helps in that regard. I have done both and typically get a few extra points when mashing out.

A mash out accomplishes a couple of things:

1. Helps ensure complete starch conversion for lower temperature mashes (e.g., 146F - 152F). At 158F - 160F, unconverted starches are quickly converted.
2. Prevents further conversion (at 162+F) during the sparge. Applicable when fly sparging.
3. Lowers the viscosity of the wort to aid in rinsing.

Will it make an obvious difference in the quality of your beer? Probably not. But, a consistent brewing process is a notable goal.

I've read multiple times on this forum where people state that they've increased their efficiency by mashing out and I have a hard time wrapping my head around that.

A: I get about 78-80% with no mash out. I get about 80-83% depending on the day when doing a mash out. Not much of a difference but I have noticed that I get slightly better when doing a mash out.

As I understand it, a mash out is to halt the enzymatic activity from the mash. That's it. You're basically raising the grainbed temp by whatever means to around 168-170 to halt the enzymes from further converting starches to sugars. That halt effectively "cements" in your mash profile.

A: A mashout does "lock in the profile". However, just because you did a mashout at 60 minutes doesn't mean that your starches weren't fully converted into sugar at 60 minutes. What happens to a certain degree when you do not do a mash out is the sugars are futher broken down into simpler more fermentable sugars by 1) a longer mash time or 2) a drop in temperature 3) both of the previous factors.

If that is true then I would think that theoretically, if anything, mashing out could potentially reduce your efficiency since you're cutting off the conversion when it could have gone on further while lautering/sparging/etc. until the wort is brought to a boil.

A: See above. I had originally thought that mashout would reduce efficiency because it's kind of like doing one less sparge round since you are using some of your potential sparge water in the mash out. However, I have found just the opposite. It seems to increase efficiency slightly. I think it may be that the initial runnings are more fluid due to the higher temperature and as a result more sugar is extracted in the initial runnings.

Personally I've never mashed out however a few of my latest beers have fermented to a lower FG than expected and I figured mashing out before lautering would be a good way to correct this issue. (In case it matters, I mash in a 10gal cylindrical cooler and do 2 equal batch sparges after lautering first runnings.)

A: I had the same problem awhile back. Everything was fermenting down to 1.006 or 1.008. I started doing a mash out and my F.G.'s came up slightly. I still mash out occasionally depending on the beer. If I don't do a mashout then I runoff directly into the BK and crank up the heat.

Mashout both halts enzymatic activity, and lowers the viscosity of the wort. You might see an incease in efficiency because your sugars are gonna flow better through the grainbed, but I imagine the increase would be minor.

lamarguy said:

A mash out accomplishes a couple of things:

1. Helps ensure complete starch conversion for lower temperature mashes (e.g., 146F - 152F). At 158F - 160F, unconverted starches are quickly converted.
2. Prevents further conversion (at 162+F) during the sparge. Applicable when fly sparging.
3. Lowers the viscosity of the wort to aid in rinsing.

Will it make an obvious difference in the quality of your beer? Probably not. But, a consistent brewing process is a notable goal.

Click to expand...

0110x011 said:

Mashout both halts enzymatic activity, and lowers the viscosity of the wort. You might see an incease in efficiency because your sugars are gonna flow better through the grainbed, but I imagine the increase would be minor.

Click to expand...

Yep. If you're batch sparing, a mash out will only increase the efficiency through further converson or through making the fluid less viscous. I think a mash out would be very minor in increasing efficiency.

A mash out is more crucial for fly sparging (continuous sparging) so that the enzymatic activity can be halted during the 45-60 minute sparge. It doen't affect the efficiency, but does avoid alteration of the mash profile.

Yoop said:

Yep. If you're batch sparing, a mash out will only increase the efficiency through further converson or through making the fluid less viscous. I think a mash out would be very minor in increasing efficiency.

A mash out is more crucial for fly sparging (continuous sparging) so that the enzymatic activity can be halted during the 45-60 minute sparge. It doen't affect the efficiency, but does avoid alteration of the mash profile.

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Thanks Yoop, I was hoping you'd chime in. Could you please elaborate on the bolded? How could you increase efficiency (collecting more sugars) if you're halting conversion by increasing temperature?

DrinkNoH2O said:

Thanks Yoop, I was hoping you'd chime in. Could you please elaborate on the bolded? How could you increase efficiency (collecting more sugars) if you're halting conversion by increasing temperature?

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Because, say your mash was at 153. You add the mash out water and stir. While you're doing that, the mash temp is increasing- 155, 157, 160, 162, etc before finally hitting the "point of no return"- when the enzymes are denatured. That tends to be at 168ish. Still, enzymes don't denature immediately. The only thing rising temps do is to increase the rate of denaturation. So, you can "squeeze" the last bit of conversion out of the unconverted starches before you hit the denaturing zone.

That's one reason you can adjust mash temperature at the beginning of the mash- if you accidently hit 162 instead of 156, you can add some cold water. The enzymes don't denature that fast.

I hope that makes sense!

Yoop said:

Because, say your mash was at 153. You add the mash out water and stir. While you're doing that, the mash temp is increasing- 155, 157, 160, 162, etc before finally hitting the "point of no return"- when the enzymes are denatured. That tends to be at 168ish. Still, enzymes don't denature immediately. The only thing rising temps do is to increase the rate of denaturation. So, you can "squeeze" the last bit of conversion out of the unconverted starches before you hit the denaturing zone.

That's one reason you can adjust mash temperature at the beginning of the mash- if you accidently hit 162 instead of 156, you can add some cold water. The enzymes don't denature that fast.

I hope that makes sense!

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Makes sense, thank you.

I still wonder though, would you convert more sugars in this "ramping" from 153 to 168 as you would just letting the mash sit there at 153 for the same amount of time (not mashing out)?




Overall I'm just trying to determine if changing my process from:

(mash, lauter, double batch sparge with ~185* water that gets the grainbed up to about 168-170*)

to

(mash, mash out, lauter, double batch sparge with ~170* water that maintains the grainbed at about 168-170*)

will increase my efficiency. I don't see any logical reason it would, but many posts on this site state otherwise.

DrinkNoH2O said:

Makes sense, thank you.

I still wonder though, would you convert more sugars in this "ramping" from 153 to 168 as you would just letting the mash sit there at 153 for the same amount of time?

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Maybe. The higher temperature would favor alpha amylase, so you may get some conversion.

I wouldn't think it would be much, as conversion is conversion. But higher temperatures favor the alpha amylase, as well as increase the rate of conversion, so it's theoretically possible.

I guess my point (and yes, I do have one!) is that conversion problems can't be fixed by a mash out. Sure, you could squeeze out a few more gravity points, but if there is a problem it's best fixed by fixing the mash conversion issues- pH, temperature, time, instead of using a mash-out as a panacea. The problem in these cases would not be the lack of a mash out, but probably a pH issue.

I know Kai has done experiments sparging with cool water, showing no loss of efficiency IF the mash conversion is complete.

Gotcha. I think my regular 73% efficiency (shooting for as high as possible) is due to an ok-but-not-fantastic crush from my LHBS and also my inability to sparge as much volume as I'd like due to my 7.5g BK (I can only collect 6.5g total - been experimenting with collecting an extra gallon, boiling main 6.5g and extra gallon separately for 30 minutes to reduce, then combining together for the regular 60 minute boil.)

I'm trying Austin Homebrew for my next brew as I've heard their crush is good however I can't increase my BK size quite yet, so I was looking for other areas to improve efficiency.

Mashing out came to mind, as again, I've read many times of members here increasing their efficiency as much as 5-10% by doing so. I've come to conclude that it could only be due to less viscous fluid/better rinsing of sugars but I don't buy a 5-10% increase because of that.

I would get 64-68% on all of my AHS crushed brews. Now I have a crusher and get a consistent 78%. I started ordering from brewmasterswarehouse.com and even when they inadvertantly crushed a couple of my batches I came in at 79% so I must be right in there on the crush. And as for everything I purchase, the prices are cheaper.
Just an FYI.

Here's the best explanation on this I've ever seen:

http://braukaiser.com/wiki/index.php/Understanding_Efficiency#Mash-out

If i remember correctly, Kai actually did some work on a "cold mash out" or "cold sparge", and determined that it didn't adversely affect efficiency on the lautering end. Some searching could probably turn it up.

I can't remember if he did this in the context of batch or fly, but of course this would not lend itself to denaturing enzymes prior to running off.

Yes, I asked him about it during his seminar at NHC this year. He said he made the same schwarzbier and sparged normally with one, and sparged with straight tap water with the other. Efficiency was the same, although the "cold" one was cloudier for some reason that he couldn't explain.