Is a mashout necessary

[Brewslikeaking]

Ive always wondered why its advised in recipes to mash out at 170'F for 10 mins for example. From what i know a mash out is to denature the enzymes to stop conversion of fermentable sugar. Does this not happen when you bring your wort to a boil?
My system is a ebiab-rims system. Once the mash time is complete i remove the bag of grain and bring it to boil as fast as i can with the assistance of the kitchen stove, not just the electric element in the kettle.

Should i be mashing out at a certain temp and why???

 

[C-Rider]

I never do/have and I produce ribbon winning beers.

 

[doug293cz]

You don't need to do a mash out. As you note, you are doing the denaturing by heating to a boil immediately after draining. Mash outs are really only for fly spargers, who might take 45 minutes or more to spage, during which some desired non-fermentable sugars could be reduced to fermentable sugars, if they didn't denature the enzymes.

Brew on

 

[AZCoolerBrewer]

You don't need to do a mash out. As you note, you are doing the denaturing by heating to a boil immediately after draining. Mash outs are really only for fly spargers, who might take 45 minutes or more to spage, during which some desired non-fermentable sugars could be reduced to fermentable sugars, if they didn't denature the enzymes.

Brew on

I think this is right. I made a Christmas beer thinking that mash out wasn't necessary. The finished beer was nice very alcoholic, but too thin due to sparging without mashing out first, but if you are going straight into a boil, there is no need.

 

[madscientist451]

Ive always wondered why its advised in recipes to mash out at 170'F for 10 mins for example. From what i know a mash out is to denature the enzymes to stop conversion of fermentable sugar. Does this not happen when you bring your wort to a boil?

You can skip the mash out if you want to.
Raising the mash temperature to 170 will decrease the viscosity of the mash, make run off easier and increase efficiency. These are important considerations in an industrial brewery with a 50 bbl brewhouse and thousands of dollars of grain being used.
On the homebrew scale, you can add a little more grain to your recipes to hit your numbers. Some people even do a cold water batch sparge or no sparge at all.

 

[johnwpowell]

I fly sparge and used to mash out but the last 2 batches I've stopped. I've heard people say it's not needed even when fly sparging but following this thread to see what the opinions are

 

[Raoul_Duke_PhD]

I had an epiphany about this just recently. My last few brews I excluded a mash-out. It's not needed for me since I run a RIMS system with full volume, no sparge.

 

[Apple_Jacker]

I noticed when I don't do a mash out, my efficiency suffers.

 

[doug293cz]

I noticed when I don't do a mash out, my efficiency suffers.

This is an indication that your starch to sugar conversion is incomplete at the end of your allotted mash time. The mash out essentially just extends the mash time, and speeds up the conversion rate during that extended time. The enzymes do not denature instantly when the temp rises, and they work faster at higher temps until they are denatured. In your case the mash out is increasing your conversion efficiency, not your lauter efficiency.

You can actually measure the degree of conversion (i.e. conversion efficiency) using the method described here. You might want to consider extending your mash times to get better conversion efficiency, and measuring the SG of the wort during the mash can tell you how long you need to mash.

Brew on

 

[enkamania]

I used to mash out because I had the thought that the hotter wort would flow easier out of my bag. Since I've stopped, I have noticed no difference in the flow rate.

 

[doug293cz]

You can skip the mash out if you want to.
Raising the mash temperature to 170 will increase the viscosity of the mash, make run off easier and increase efficiency. These are important considerations in an industrial brewery with a 50 bbl brewhouse and thousands of dollars of grain being used.
On the homebrew scale, you can add a little more grain to your recipes to hit your numbers. Some people even do a cold water batch sparge or no sparge at all.

I think you meant to say "will decrease the viscosity."

Wort viscosity only decreases by about 16% when heated from 150°F to 170°F (ref.) This might have a small effect on the max rate at which you can drain a mash, but when fly sparging you don't want to drain at anywhere near the maximum rate, as that will just encourage more channeling. So, in practice, run off rate is not limited by wort viscosity, but rather limiting channeling and/or avoiding a stuck sparge. Lauter efficiency is also not affected by the initial wort viscosity, as the efficiency is determined by the sugar remaining in the grain bed after the residual wort in the grain bed has been diluted about 8X (or more.) The lauter efficiency (in the absence of channeling) is determined by when the sparge is stopped, which in turn is determined by having achieved target pre-boil volume or minimum run off SG.

Brew on

 

[ebstauffer]

Im confused. With respect to BIAB, what is a mashout? My recollection from HTB is primarily to halt enzyme activity effectively locking in the fermentable profile / mouthfeel of the final beer. I can think of no simpler way to mashout that to fire up the element(s) or fire up the burner. Frankly I dont know how can't not mashout when BIABing. What am I missing?

 

[doug293cz]

Im confused. With respect to BIAB, what is a mashout? My recollection from HTB is primarily to halt enzyme activity effectively locking in the fermentable profile / mouthfeel of the final beer. I can think of no simpler way to mashout that to fire up the element(s) or fire up the burner. Frankly I dont know how can't not mashout when BIABing. What am I missing?

A mash out is heating the mash before running off/draining the wort. It can be a useful technique when fly sparging. When doing batch sparge or no-sparge, starting the heat to boil accomplishes the same thing (denaturing enzymes) on a similar scale as mash out, so a separate mash out step is unneeded.

Brew on

 

[madscientist451]

Yes, doug293cz, I meant to say decrease viscosity, thanks

 

[MSK_Chess]

Its my understanding that a mash out done at around 72-75 Celsius (162 -167F) also supercharges the alpha amylase enzymes to convert Amylopectin which cannot be achieved by beta amylase on its own. In other words its converts any left over starches that may be unconverted.

The starch found in malt is composed from Amylose and Amylopectin. Amylose is a single chain of glucose molecules linked between their 1st and 4th carbon atom (called 1-4 link). 17-24% of barley starch is Amylose [Narziss, 2005] the remaining 76-83% is Amylopectin. Amylopectin has a branched structure. These branches are formed by bonds between the 1st and 6th carbon atom of 2 glucose rings (called 1-6 link).

Beta amylase produces Maltose, the main wort sugar, by splitting 2 glucose molecules from the non-reducing end of a glucose chain. It is therefore able to completely convert Amylose. But since it cannot get past the branch joins, Amylopectin cannot completely be converted by beta amylase. The optimal pH range for beta amylase between 5.4 and 5.6 and the optimal temperature range is between 140ºF (60ºC) and 150ºF (65ºC). Above 160ºF (70ºC) beta amylase is quickly deactivated [Narziss, 2005].

Alpha Amylase is able to split 1-4 links within glucose chains. By doing so, it exposes additional non-reducing ends for the beta amylase. This allows for the further conversion of Amylopectin. The optimal pH range is between 5.6 and 5.8 and the optimal temperature range is between 162ºF (72ºC) and 167ºF (75ºC). Above 176ºF (80ºC) alpha amylase is quickly deactivated [Narziss, 2005]

https://www.homebrewtalk.com/wiki/index.php/The_Theory_of_Mashing

 

[ebstauffer]

A mash out is heating the mash before running off/draining the wort. It can be a useful technique when fly sparging. When doing batch sparge or no-sparge, starting the heat to boil accomplishes the same thing (denaturing enzymes) on a similar scale as mash out, so a separate mash out step is unneeded.

Brew on

Indeed. I suppose my question was specific to BIAB -- there really is no mashout.

 

[doug293cz]

Its my understanding that a mash out done at around 72-75 Celsius (162 -167F) also supercharges the alpha amylase enzymes to convert Amylopectin which cannot be achieved by beta amylase on its own. In other words its converts any left over starches that may be unconverted.

The starch found in malt is composed from Amylose and Amylopectin. Amylose is a single chain of glucose molecules linked between their 1st and 4th carbon atom (called 1-4 link). 17-24% of barley starch is Amylose [Narziss, 2005] the remaining 76-83% is Amylopectin. Amylopectin has a branched structure. These branches are formed by bonds between the 1st and 6th carbon atom of 2 glucose rings (called 1-6 link).

Beta amylase produces Maltose, the main wort sugar, by splitting 2 glucose molecules from the non-reducing end of a glucose chain. It is therefore able to completely convert Amylose. But since it cannot get past the branch joins, Amylopectin cannot completely be converted by beta amylase. The optimal pH range for beta amylase between 5.4 and 5.6 and the optimal temperature range is between 140ºF (60ºC) and 150ºF (65ºC). Above 160ºF (70ºC) beta amylase is quickly deactivated [Narziss, 2005].

Alpha Amylase is able to split 1-4 links within glucose chains. By doing so, it exposes additional non-reducing ends for the beta amylase. This allows for the further conversion of Amylopectin. The optimal pH range is between 5.6 and 5.8 and the optimal temperature range is between 162ºF (72ºC) and 167ºF (75ºC). Above 176ºF (80ºC) alpha amylase is quickly deactivated [Narziss, 2005]

https://www.homebrewtalk.com/wiki/index.php/The_Theory_of_Mashing

All true. But think about this: A very fine crush mash can be 100% converted in 20 minutes or less, whereas a coarse crush mash is seldom 100% converted in an hour, or even 90 minutes (as demonstrated by the difference in yield between the fine grind and coarse grind congress mashes.) This means it doesn't take the amylase enzymes much time to complete their work. So something other than the amylase enzyme action is controlling the overall rate of conversion during the mash, and it is strongly affected by the grit size (crush fineness.)

This rate limiting step is gelatinization, in which the surfaces of the grits absorb large amounts of water, turning the surface starch from a dense solid to spongy layers where the starch chains are surrounded by lots of water molecules. Once the starch is gelatinized, the enzymes can start chopping up the starch chains. The alpha amylase can cleave off sizable chunks, which then become soluble, so they can then diffuse away from the surfaces of the grits, and undergo further enzyme action in the bulk wort.

As the starch is solubilized and departs the grit surface, water is allowed to penetrate further thru the gelatinized layer into the grit, gelatinizing deeper into the grits. This continues until all the grits have been completely gelatinized, or something interrupts the process. Gelatinization will slow down after the alpha amylase is denatured, as the solubilization of the starch in the gelatinized layers will slow down, slowing down the diffusion of water towards the center of the grits as the gelatinized layer thickness increases.

I will posit that the increase in conversion rate during a mash out is more due to increased rates of gelatinization of remaining starches, than increases in activity of alpha amylase.

Brew on

 

[phyllobeddo]

I'm 63 BIAB batches in and I've never done a mash out. I've made some great beers and some not so great ones. I don't think a mash out would have helped either way! Cheers!

 

[MSK_Chess]

Mash out produces better head retention.

This rest is held between 160ºF (70ºC) and 164ºF (72ºC) which is well above the gelatinization temperatuere for barley starch and within the optimal temperature range for alpha Amylase which will quickly convert the remaining starches. This rest is usually held until conversion of the mash is complete. An other benefit of this rest is the formation of foam positive glyco proteins [Fix, 1999]

https://www.homebrewtalk.com/wiki/index.php/The_Theory_of_Mashing

 

[MSK_Chess]

All true. But think about this: A very fine crush mash can be 100% converted in 20 minutes or less, whereas a coarse crush mash is seldom 100% converted in an hour, or even 90 minutes (as demonstrated by the difference in yield between the fine grind and coarse grind congress mashes.) This means it doesn't take the amylase enzymes much time to complete their work. So something other than the amylase enzyme action is controlling the overall rate of conversion during the mash, and it is strongly affected by the grit size (crush fineness.)

This rate limiting step is gelatinization, in which the surfaces of the grits absorb large amounts of water, turning the surface starch from a dense solid to spongy layers where the starch chains are surrounded by lots of water molecules. Once the starch is gelatinized, the enzymes can start chopping up the starch chains. The alpha amylase can cleave off sizable chunks, which then become soluble, so they can then diffuse away from the surfaces of the grits, and undergo further enzyme action in the bulk wort.

As the starch is solubilized and departs the grit surface, water is allowed to penetrate further thru the gelatinized layer into the grit, gelatinizing deeper into the grits. This continues until all the grits have been completely gelatinized, or something interrupts the process. Gelatinization will slow down after the alpha amylase is denatured, as the solubilization of the starch in the gelatinized layers will slow down, slowing down the diffusion of water towards the center of the grits as the gelatinized layer thickness increases.

I will posit that the increase in conversion rate during a mash out is more due to increased rates of gelatinization of remaining starches, than increases in activity of alpha amylase.

Brew on

A finer crush simply gives the beta amylase more time to work to increase maltose and thus fermentability which you may or may not want depending on the syle of beer you are targeting. Regardless of the crush beta amylase cannot convert Amylopectin and thus this appears to me to be temperature dependent.

crush - a finer crush makes the starches accessible more quickly thus giving the beta amylase more time to work on their conversion before it is deactivated. The results is increased fermentability.

https://www.homebrewtalk.com/wiki/index.php/The_Theory_of_Mashing

 

[doug293cz]

Mash out produces better head retention.

This rest is held between 160ºF (70ºC) and 164ºF (72ºC) which is well above the gelatinization temperatuere for barley starch and within the optimal temperature range for alpha Amylase which will quickly convert the remaining starches. This rest is usually held until conversion of the mash is complete. An other benefit of this rest is the formation of foam positive glyco proteins [Fix, 1999]

https://www.homebrewtalk.com/wiki/index.php/The_Theory_of_Mashing

What's a hold between 160° and 164°F got to do with mash out at 168° - 170°F, other than you have to pass thru that temp range to get to mash out? You have to pass thru that temp range no matter whether you do a mash out or not. Formation of foam beneficial proteins has nothing to do with efficiency, which has been the focus of the discussion so far (look a wookie .) I already noted that you have to completely gelatinize the starch for complete conversion, and once gelatinized, conversion is very fast. It's all about how long it takes to finish gelatinization.

Brew on

 

[doug293cz]

A finer crush simply gives the beta amylase more time to work to increase maltose and thus fermentability which you may or may not want depending on the syle of beer you are targeting. Regardless of the crush beta amylase cannot convert Amylopectin and thus this appears to me to be temperature dependent.

crush - a finer crush makes the starches accessible more quickly thus giving the beta amylase more time to work on their conversion before it is deactivated. The results is increased fermentability.

https://www.homebrewtalk.com/wiki/index.php/The_Theory_of_Mashing

A finer crush doesn't give the beta amylase more time, as the lifetime is dependent on temp. The finer crush makes more starch available sooner, so more beta action can occur during the lifetime of the beta amylase.

It is also a common misunderstanding that says alpha amylase cannot create highly fermentable wort. Alpha amylase cuts glucose chains at random points (as long as they aren't too close to a branch.) Given enough time random chopping will reduce everything to mono and di-saccharides (which are fermentable) and limit dextrins which cannot be further affected by alpha amylase. Alpha amylase is not as efficient at creating small sugars compared to larger chunks, but that's just a rate affect, not a capability limit. As proof of this, look for the threads on fixing stuck fermentations by adding alpha amylase. Yes, alpha will even increase the fermentability of low fermentability worts at fermentation temperatures. It just works a lot slower at those temps.

My personal belief is that the higher fermentability limits available with low temp mashes are more due to action by limit dextrinase than beta amylase. Limit dextrinase can chop the 1-6 branching bond, thus reducing the amount of limit dextrinase remaining after complete saccharification by the amylases. Less limit dextrinase means more fermentable sugars at the limit of saccharification. Read about limit dextrinase here.

Brew on

 

[MSK_Chess]

What's a hold between 160° and 164°F got to do with mash out at 168° - 170°F, other than you have to pass thru that temp range to get to mash out? You have to pass thru that temp range no matter whether you do a mash out or not. Formation of foam beneficial proteins has nothing to do with efficiency, which has been the focus of the discussion so far (look a wookie .) I already noted that you have to completely gelatinize the starch for complete conversion, and once gelatinized, conversion is very fast. It's all about how long it takes to finish gelatinization.

Brew on

What's a hold between 160° and 164°F got to do with mash out at 168° - 170°F

Actually as the article points out alpha amylase is active up until about 77 degrees Celsius and only denatured at temperatures above to this. So if you hold a mashout at 74-75 Celsius for ten-fifteen minutes you will be supercharging the alpha amylase activity will you not? (most recipes I know have a schedule set at temperatures between 74-76 Celsius for mashout)

No one is claiming that the formation of foam causing proteins is a contingency of efficiency? The OP asked why a mash out? One of the reasons is that it helps with the formation of foam beneficial proteins. He mentions nothing about efficiency.

Alpha amylase - The optimal pH range is between 5.6 and 5.8 and the optimal temperature range is between 162ºF (72ºC) and 167ºF (75ºC). Above 176ºF (80ºC) alpha amylase is quickly deactivated [Narziss, 2005] -

https://www.homebrewtalk.com/wiki/index.php/The_Theory_of_Mashing

 

[MSK_Chess]

A finer crush doesn't give the beta amylase more time, as the lifetime is dependent on temp. The finer crush makes more starch available sooner, so more beta action can occur during the lifetime of the beta amylase.

It is also a common misunderstanding that says alpha amylase cannot create highly fermentable wort. Alpha amylase cuts glucose chains at random points (as long as they aren't too close to a branch.) Given enough time random chopping will reduce everything to mono and di-saccharides (which are fermentable) and limit dextrins which cannot be further affected by alpha amylase. Alpha amylase is not as efficient at creating small sugars compared to larger chunks, but that's just a rate affect, not a capability limit. As proof of this, look for the threads on fixing stuck fermentations by adding alpha amylase. Yes, alpha will even increase the fermentability of low fermentability worts at fermentation temperatures. It just works a lot slower at those temps.

My personal belief is that the higher fermentability limits available with low temp mashes are more due to action by limit dextrinase than beta amylase. Limit dextrinase can chop the 1-6 branching bond, thus reducing the amount of limit dextrinase remaining after complete saccharification by the amylases. Less limit dextrinase means more fermentable sugars at the limit of saccharification. Read about limit dextrinase here.

Brew on

I see then perhaps we should alert the author of the article. Here is a direct quotation from the homebrewtalk article on the theory of mashing. While stating that temperature is the primary determinant in effecting amylase activity the article mentions various other variables that have some influence.

crush - a finer crush makes the starches accessible more quickly thus giving the beta amylase more time to work on their conversion before it is deactivated. The results is increased fermentability

to which you have stated : A finer crush doesn't give the beta amylase more time, as the lifetime is dependent on temp. The finer crush makes more starch available sooner, so more beta action can occur during the lifetime of the beta amylase.

If you don't mind me saying I think that the above is not a little self contradictory. Yes the lifetime of amylase activity is primarily temperature dependent however if there is more starch available due to a finer crush it makes absolute sense as the author of the article points out and as you yourself acknowledge that a finer crush does indeed give the beta amylase more starch more quickly and thus as a direct consequence more time to convert starches before it is denatured due to temperature.

from the same article

Limit dextrinase is able to split the 1-6 links that are found in Amylopectin. It is therefore able to reduce the amount of limit dextrins (glucose chains containing a 1-6 link) which are left over by alpha and beta amylase activity. Its optimal pH is 5.1 and the optimal temperature range is between 133ºF (55ºC) and 140ºF (60ºC). Above 149ºF (65ºC) this enzyme is quickly deactivated [Narziss 2005]. Because of an optimal temperature well below the commonly used saccrification rest temperature for single temperature saccrification rests, this enzyme plays only a mior role in most mashing schedules. Extended rests in the lower and upper 130sºF (upper 50sºC) benefit a higer fermentability of the wort. -

https://www.homebrewtalk.com/wiki/index.php/The_Theory_of_Mashing

To what extent this higher fermentability is due to the activity of limit dextrins or beta amylase I cannot say. Perhaps it is a function of both?

Its all a bit academic, what we are really interested in is targeting a mash schedule that helps us achieve the style of beer that we are hoping to make. Dry, full bodied etc etc

 

[MSK_Chess]

Its really interesting. If we take someone that does a full no sparge BIAB, they will remove their grains after mashing and immediately raise temperature to boiling. If their grains have been mashing at say 66 Celsius it will take maybe ten minutes to reach 80 Celsius when the amylase activity is completely denatured. During this time they will have gone through the optimal temperature range for alpha amylase for roughly about ten minutes.

If we compare this to someone that fly sparges and targets a mash out they will hold optimal alpha amylase range of 75 Celsius and hold that for ten to fifteen minutes, further to this they will sparge for at least 15-30 min in the same range. (usually mash out sparge water is heated to around 80 Celsius aiming for a target of about 75) What this means is that the fly sparger has his or her mash sitting at 75 Celsius for at least 25-30 minutes longer than the no sparge BIAB brewer.

Is this significant? I believe so.

(I apologise to our American cousins for writing in centigrade)

 

[SlitheryDee]

I guess it depends on how exacting you are in getting the beer you're shooting for. Once you've got everything so dialed in that all you have left to worry about is the precise final body and alcohol content of your beer then maybe you play with mashouts to stop conversion at the instant it needs to be stopped. For most of us I'd guess that we have a lot of bigger considerations to deal with before we get down to mashouts though.

 

[MSK_Chess]

This is also incredibly interesting and perhaps Doug or anyone else can correct me if I am wrong. Mashout only denatures beta amylase, it does not denature the alpha amylase enzymatic activity which is still active until the high seventies centigrade (170F) Its primary goal is to lessen the viscosity of the mash and to make lautering more easy for those that fly sparge. Its easy to see why this would seem unnecessary for no sparge BIAB brewers but I really wonder if they would not benefit from an extended mashout rest held at around 75 Celsius (167F) for reasons already specified.