Why mash out?

[Brewslikeaking]

Can someone tell me the exact reason you would mash out. If your going to boil it anyway what's the point?

 

[RM-MN]

Mash out is used in fly sparging where at the end of the mash period when you should have your sugar/destrine ratio where you want it for the malt profile of your beer and you want to keep it that way. With fly sparging you would be adding sparge water slowly while draining wort from the kettle and your grains would still be at mash temperature so conversion could still be occuring, especially the action of the beta amylase which would make your wort more fermentable. If you "mash out" at the end of the mash period before you begin sparging, the high temperature (relative to the mash temp) will denature (destroy the action) of the enzymes, locking in the fermentable/unfermentable sugar ratios. It really only applies to fly sparging because with batch sparging, you are stirring the sparge water into the grains, then immediately draining the mash tun, leaving the enzymes little time to act.

 

[Cyclman]

It also makes the mash run more freely when fly sparging.

 

[Singletrack]

I batch sparge, so I do not mash out, but I use hot water for the sparge that raises the temp to 168 F. I've always thought that the idea of a mash out -- even for fly spargers -- was a bit of a crap shoot. Why are they trying to lock in the sugar-dextrin ratio at 60 min instead of 45 min or 90 min or just let it go for 120 min during the fly sparge? Some people claim conversion occurs in 10 to 15 min, so why don't I have watery thin beer when I mash low and let it go 90 min? (Could be the malt bill I suppose.)

 

[doug293cz]

It also makes the mash run more freely when fly sparging.

Anyone know where to find information on wort viscosity as a function of temperature and specific gravity? This information could quantify how much higher temps (~170°F vs ~150°F) would speed run off.

Brew on

 

[doug293cz]

I batch sparge, so I do not mash out, but I use hot water for the sparge that raises the temp to 168 F. I've always thought that the idea of a mash out -- even for fly spargers -- was a bit of a crap shoot. Why are they trying to lock in the sugar-dextrin ratio at 60 min instead of 45 min or 90 min or just let it go for 120 min during the fly sparge? Some people claim conversion occurs in 10 to 15 min, so why don't I have watery thin beer when I mash low and let it go 90 min? (Could be the malt bill I suppose.)

May also be a function of crush coarseness. @RN-MN has reported issues with high fermentability and low body when using extremely fine crushes. There are theoretical reasons based on diffusion distance and speed that help make sense of this.

Brew on

 

[adainxiao]

I've always thought that the idea of a mash out

 

[Brewslikeaking]

Mash out is used in fly sparging where at the end of the mash period when you should have your sugar/destrine ratio where you want it for the malt profile of your beer and you want to keep it that way. With fly sparging you would be adding sparge water slowly while draining wort from the kettle and your grains would still be at mash temperature so conversion could still be occuring, especially the action of the beta amylase which would make your wort more fermentable. If you "mash out" at the end of the mash period before you begin sparging, the high temperature (relative to the mash temp) will denature (destroy the action) of the enzymes, locking in the fermentable/unfermentable sugar ratios. It really only applies to fly sparging because with batch sparging, you are stirring the sparge water into the grains, then immediately draining the mash tun, leaving the enzymes little time to act.

So your saying mashing out only occurs when fly sparring because of the length of time fly sparging takes? And in batch sparging even though the temp is hot enough there isn't enough time to stop the enzymes working?

 

[RM-MN]

So your saying mashing out only occurs when fly sparring because of the length of time fly sparging takes? And in batch sparging even though the temp is hot enough there isn't enough time to stop the enzymes working?

It isn't that the enzymes aren't stopped if you "mash out" with a batch sparge, its that there is no need to do the mash out as you will have sparged and begun the boil so quickly (the boil stops the enzyme activity for sure) that the enzymes don't have time to act any more on your mash. In batch sparging you are getting more of the sugars off the grains and all that takes is water and good stirring. No waiting is needed. It's more like putting sugar into your tea. It only needs stirring for a short amount of time to get it dissolved but if you don't stir it wants to sit on the bottom of the cup.

 

[joshesmusica]

so is there any point to when beersmith tells me to do a mash out step on biab? or should i just not care about that and pull the grains when conversion is complete?

 

[OkanaganMike]

so is there any point to when beersmith tells me to do a mash out step on biab? or should i just not care about that and pull the grains when conversion is complete?

Great question! I want to know too.

 

[user 141939]

I disagree with the statement that batch sparging doesn't require mash-out. It depends on the system.

 

[user 141939]

I batch sparge and it takes me a half hour or so to collect all my runnings. I have to drain somewhat slow to avoid it sticking. I feel like this time is enough to "thin out" the wort when I don't do a mash out.

 

[OkanaganMike]

oops, double post

 

[Gavin C]

My understanding of a mashout is that it has a twofold application.

1: Denature the amylase enzymes stopping conversion
2: Reducing the viscosity of the sweet wort/grain mixture facilitating a better rinsing of the grains and a more sugars being removed from the mash.

I also use the BIAB method and have found a short mash-out rest at 168F to be of benefit to my efficiency and consistency. YMMV of course.

 

[Gameface]

so is there any point to when beersmith tells me to do a mash out step on biab? or should i just not care about that and pull the grains when conversion is complete?

Beersmith only tells you to do a mashout if you've chosen a mash profile that includes a mashout. Go back in to your mash profile and select essentially the same mash except that it says "no mashout" and beersmith will stop telling you to do a mashout.

 

[doug293cz]

My understanding of a mashout is that it has a twofold application.

1: Denature the amylase enzymes stopping conversion
2: Reducing the viscosity of the sweet wort/grain mixture facilitating a better rinsing of the grains and a more sugars being removed from the mash.

I also use the BIAB method and have found a short mash-out rest at 168F to be of benefit to my efficiency and consistency. YMMV of course.

RE: #2

Higher temp will reduce the viscosity, but I've never seen that quantified. If you know of any data on how much the viscosity drops going from 150°F to 170°F, please post a link. As for getting more sugar: In a completely converted mash you will not get more sugar into the wort at higher temperatures, as there is no more sugar to dissolve. Maltose (and other sugar) concentrations in wort at mash temps are far below saturation (http://chestofbooks.com/food/science/Experimental-Cookery/Solubility-Of-Maltose-In-Water-gillis.html), so all available sugar is dissolved easily.

Brew on

 

[CUrchin]

My understanding of a mashout is that it has a twofold application.

1: Denature the amylase enzymes stopping conversion
2: Reducing the viscosity of the sweet wort/grain mixture facilitating a better rinsing of the grains and a more sugars being removed from the mash.

I also use the BIAB method and have found a short mash-out rest at 168F to be of benefit to my efficiency and consistency. YMMV of course.

Can you quantify the increased efficiency you get with BIAB and doing mashout? I used to do a mashout with BIAB, but I didn't think it was really helping anything. I also do a bit of a sparge by sprinkling water over the grains sitting on a rack over my pot. Perhaps that has a similar effect.

Cheers.

 

[chickypad]

Beersmith only tells you to do a mashout if you've chosen a mash profile that includes a mashout. Go back in to your mash profile and select essentially the same mash except that it says "no mashout" and beersmith will stop telling you to do a mashout.

This is what I was going to say, that you should be telling Beersmith what to do not the other way around. If you don't find a default profile that fits your actual process then modify one and save it. You can add and delete steps from within the mash profile page.

 

[Gavin C]

RE: #2

As for getting more sugar: In a completely converted mash you will not get more sugar into the wort at higher temperatures, as there is no more sugar to dissolve. :

I'm not suggesting you get more sugars into the mash at the higher temps. I'm saying it better facilitates getting the sugars that already in the mash, out.

 

[OkanaganMike]

I'm not suggesting you get more sugars into the mash at the higher temps. I'm saying it better facilitates getting the sugars that already in the mash, out.

I've read this elsewhere, how does this work? I could see if you brought it up to a boil you may release some of the "trapped" sugars between the packed grain bed through agitation of the boil thus averaging out the sugar concentration. But we're not boiling.

Still learning and want to understand, not questioning your experience.

 

[doug293cz]

I'm not suggesting you get more sugars into the mash at the higher temps. I'm saying it better facilitates getting the sugars that already in the mash, out.

Can you explain the physical/chemical mechanism behind this? Is there something more to it than just the lower viscosity allowing it to happen a little faster?

Brew on

 

[Auger]

Can you explain the physical/chemical mechanism behind this? Is there something more to it than just the lower viscosity allowing it to happen a little faster?

Brew on

I always thought of it like honey at room vs. heated, but to a lesser degree. I'm not sure of the exact mechanism that heat decreases viscosity, but it is readily apparent in that case.

 

[doug293cz]

Hmmm. Found an interesting bit of relevant and surprising information here:

"Coagulation of mash particles is favoured by an increase in final mash temperature, though this may also increase wort viscosity, which will tend to offset the beneficial effects of coagulation on run off rates."​

This says that wort doesn't act like a pure sugar solution, in that the wort viscosity can increase with temperature, rather than decrease. But, since wort contains all kinds of stuff besides sugar, maybe we shouldn't be surprised.

So, mash out may not in fact decrease wort viscosity as most of us have assumed.

Brew on

 

[TasunkaWitko]

Why mash out?

Three pages of conflicting theories and speculation. It seems to me that the best way to determine the answer to this question is two brew two batches that are identical in every way - except that one is mashed out and the other is not. Compare the resulting characteristics at each subsequent stage in the process, and I bet you will have your answer.

 

[Gavin C]

Can you quantify the increased efficiency you get with BIAB and doing mashout? I used to do a mashout with BIAB, but I didn't think it was really helping anything. I also do a bit of a sparge by sprinkling water over the grains sitting on a rack over my pot. Perhaps that has a similar effect.

Cheers.

I don't have much in the way of data other than 1 batch that I eliminated the mash-out from my process. I got a 4% drop in BH efficiency and found that the grain held onto a slightly greater volume of wort. Now this is anecdotal evidence of the poorest caliber and could certainly not be used to support or refute the use of a mash-out. Only personal experience of which I do not have much. (1 year brewing and 15 or so batches)

The way I look at it is this. If we take the corollary of a high temperature mash out, and decided to cool the mash to 35F to shut off the enzymatic activity I would envisage a cool sticky bag of grains that would hold on to a great deal of sugar once lautering was done. Using this mental model it would seem to make sense that a less viscous hotter mash would be useful prior to lautering; ie a mashout at a temperature high enough to allow this without extracting tannins (168-170F)

Now I am not for a moment suggesting this to be done for a number of obvious reasons not least the fact that the enzymes will not be denatured, only inactivated. As I said just a mental model.

With a 5 minute mash-out at 168F I get consistent results and I lose about 0.04- 0.045 gallons per pound of grain to absorbtion. (Don't have my data in front of me but it is always in this range)

Hope that may somewhat answer the question.

 

[doug293cz]

Three pages of conflicting theories and speculation. It seems to me that the best way to determine the answer to this question is two brew two batches that are identical in every way - except that one is mashed out and the other is not. Compare the resulting characteristics at each subsequent stage in the process, and I bet you will have your answer.

Great idea! When will you have this done? Please provide regular updates on your progress.

(Sorry, I'm feeling a little snarky today. I learned to be careful about making suggestions for things to do at work, since management usually responded in the same manner I responded to you. )

Edit: The resolution to all the conflicting information is to try different methods, and use whichever options give you results that you are happy with. There seem to be infinite variations on how to brew beer, and many of them actually work quite well.
Brew on

 

[Gavin C]

Can you explain the physical/chemical mechanism behind this? Is there something more to it than just the lower viscosity allowing it to happen a little faster?

Brew on

I don't know doug. You'd need to ask folks a lot more in the know than myself, I'm afraid.

 

[doug293cz]

I don't have much in the way of data other than 1 batch that I eliminated the mash-out from my process. I got a 4% drop in BH efficiency and found that the grain held onto a slightly greater volume of wort. Now this is anecdotal evidence of the poorest caliber and could certainly not be used to support or refute the use of a mash-out. Only personal experience of which I do not have much. (1 year brewing and 15 or so batches)

The way I look at it is this. If we take the corollary of a high temperature mash out, and decided to cool the mash to 35F to shut off the enzymatic activity I would envisage a cool sticky bag of grains that would hold on to a great deal of sugar once lautering was done. Using this mental model it would seem to make sense that a less viscous hotter mash would be useful prior to lautering; ie a mashout at a temperature high enough to allow this without extracting tannins (168-170F)

Now I am not for a moment suggesting this to be done for a number of obvious reasons not least the fact that the enzymes will not be denatured, only inactivated. As I said just a mental model.

With a 5 minute mash-out at 168F I get consistent results and I lose about 0.04- 0.045 gallons per pound of grain to absorbtion. (Don't have my data in front of me but it is always in this range)

Hope that may somewhat answer the question.

Yeah, at lower temps the viscosity will increase enough to be an issue. The question is whether going from mash to mash out temps gives a drop in viscosity large enough to be significant, or if viscosity even drops at all?

If you are happy with your process which includes mash out, by all means, stick with it. I'm not trying to convince anyone to do something one way or the other, just trying to determine what is based on verifiable fundamentals vs. conventional wisdom or personal preference. Personal preference should triumph in the absence of hard evidence that there really is a wrong way to do something.

Your grain absorption appears to be quite low. Typical numbers run from 0.08 to 0.125 gal/lb, and the lowest I have achieved is 0.06 gal/lb. Are you squeezing, or doing something else, to get more wort out?

Brew on

 

[Gavin C]

Are you squeezing, or doing something else, to get more wort out?

Yes I squeeze.