Mash out - how and why

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KrazySquirrel

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Reposted from the All-Grain...

So this is a two part question about the mash out temp at the end of the starch conversion. I brew on an electric all grain system in my basement using 2000 Watt heat sticks and mash in a cooler. The cooler keeps the mash temp fairly consistent, but I don't perform a mash out to my beers because I don't want to put the heat stick in the cooler and melt the plastic and feel that I'd need a lot more hot water than my sparge calls for to raise the temp. I make decent beers, but they tend to finish dry and some a little astringent. My mash temps are usually 145 -154 which will lend a drier beer, but I'm wondering if the lack of the mash out is contributing to the dry finish.

1. How do other electric brewers (non-RIMS/HERMS) perform a mash out?

2. Is a mash out necessary?

Thanks in advance for your help!
 
The mash out step is done to stop the saccrification process. you can do this several ways, but the easiest if you don't have a Direct fire mash tun, a HERMS, or a RIMS system, is to do a step infusion. You can do this by adding a volume of 200ºF water to your mash. There are calculators or calculations you need to use to determine the amount of water you need to add to raise your temp from, say 150 to 170.

The reason people do a mash out step is to prevent over mashing. During the mashing process, Alpha amylase breaks long starches down into different sized long chain sugars. These for the most part are the un-fermentable sugars that contribute to mouthfeel, but not to flavor. During a normal mashing process, there will be a random distribution of different size long-chain sugars, that contribute differently to mouthfeel. If the mash goes too long and Alpha-amylase is not stopped ether by boiling or a mash out step you can endup with mostly shorter non-fermentable sugars, giving the beer a thin mouthfeel.

That said, on the home brew scale this might not be a problem, especially if you are starting to heat for the boil as you are collecting your sparge. in this case the heating of the kettle will stop further mashing. But if you are collecting your full volume before you start your boil, you will be effectively continuing your mash in the kettle, until you start to heat your kettle past 170ºF, and denature the mash enzymes.

If you find your beers to be thin, you might want to try a mash out step, or a shorter mash, or to start heating your kettle as it is filling.

As for astringency, extraction of tannons from the grain is predominately due to you pH getting to high or basic. This can be simply due to diluting your running too far. The pH of your mash will be around 5.3, but as it gets more dilute from your sparge water it can get up towards pH7 and 8 (depending on your water) and start to extract tannons. You can prevent this by acidifying your sparge water, and or mashing with more grains and sparging less.

Hope this helps.
B^2
 
Bsquared said:
The reason people do a mash out step is to prevent over mashing. During the mashing process, Alpha amylase breaks long starches down into different sized long chain sugars. These for the most part are the un-fermentable sugars that contribute to mouthfeel, but not to flavor. During a normal mashing process, there will be a random distribution of different size long-chain sugars, that contribute differently to mouthfeel. If the mash goes too long and Alpha-amylase is not stopped ether by boiling or a mash out step you can endup with mostly shorter non-fermentable sugars, giving the beer a thin mouthfeel.
Click to expand...

While I agree that this is one reason, it isn't the only reason.
If you're mashing at temps where beta amylaze is more active, you can get beers that finish quite dry.
I often find that I get dry beers on my system, because of a few different factors.
One main contributor is when I allow the enzymes to keep working, in my first runnings.
If I don't get the kettle heating, those beta enzymes just keep working on the runnings & making my wort extremely fermentable & I will see final gravities down near 1.002.

Doing a mash out and/or heating the kettle faster would (& does) put a stop to this.
 
Bsquared said:
The mash out step is done to stop the saccrification process. you can do this several ways, but the easiest if you don't have a Direct fire mash tun, a HERMS, or a RIMS system, is to do a step infusion. You can do this by adding a volume of 200ºF water to your mash. There are calculators or calculations you need to use to determine the amount of water you need to add to raise your temp from, say 150 to 170.

The reason people do a mash out step is to prevent over mashing. During the mashing process, Alpha amylase breaks long starches down into different sized long chain sugars. These for the most part are the un-fermentable sugars that contribute to mouthfeel, but not to flavor. During a normal mashing process, there will be a random distribution of different size long-chain sugars, that contribute differently to mouthfeel. If the mash goes too long and Alpha-amylase is not stopped ether by boiling or a mash out step you can endup with mostly shorter non-fermentable sugars, giving the beer a thin mouthfeel.

That said, on the home brew scale this might not be a problem, especially if you are starting to heat for the boil as you are collecting your sparge. in this case the heating of the kettle will stop further mashing. But if you are collecting your full volume before you start your boil, you will be effectively continuing your mash in the kettle, until you start to heat your kettle past 170ºF, and denature the mash enzymes.

If you find your beers to be thin, you might want to try a mash out step, or a shorter mash, or to start heating your kettle as it is filling.

As for astringency, extraction of tannons from the grain is predominately due to you pH getting to high or basic. This can be simply due to diluting your running too far. The pH of your mash will be around 5.3, but as it gets more dilute from your sparge water it can get up towards pH7 and 8 (depending on your water) and start to extract tannons. You can prevent this by acidifying your sparge water, and or mashing with more grains and sparging less.

Hope this helps.
B^2
Click to expand...

Regarding oversparging I know there is a specific gravity you should not sparge past to avoid oversparging. Do you know what that gravity is??? I don't track Ph in my brewing currently but I do have a refractometer to check gravity.
 
I will second the mash out infusion method with boiling water. It's easy and effective. Another thing is that 145 is too low. I've found that if I mash below 151, I get a thin feeling beer. I mash all my brews between 151 and 156 because I have been keeping the gravities below 1.050, and I find it keeps them richer feeling. As for mash pH, there is a product called 5.2 Mash and it's a buffer. You add it to your strike water, and it will maintain your mash at 5.2 for the duration, reducing any astringency you might get from a high pH. When sparging, I've read that you should stop when the gravity of the runoff reaches 1.010.
 
horseinmay said:
...As for mash pH, there is a product called 5.2 Mash and it's a buffer. You add it to your strike water, and it will maintain your mash at 5.2 for the duration, reducing any astringency you might get from a high pH.
Click to expand...

Be aware that the 5.2 buffer will not work if your water is high in alkalinity.
My water has bicarbonate content over 350 ppm & renders 5.2 useless.
 
Brew-ta-sauraus said:
Regarding oversparging I know there is a specific gravity you should not sparge past to avoid oversparging. Do you know what that gravity is??? I don't track Ph in my brewing currently but I do have a refractometer to check gravity.
Click to expand...

below 1.010 is the point where you start 'oversparging'

also- almost all commonly used malts are "fully-modified" and really just require one single infusion mash at around 150-156 degrees. doing more rests, and lower temperature rests, than that is largely unnecessary unless you are using lots of under-modified malts that require more protein conversion. overdoing it with multiple rests can even negatively impact the finished beer.


https://www.homebrewtalk.com/f12/malt-modification-how-read-malt-analysis-sheet-143252/
 
KitB said:
While I agree that this is one reason, it isn't the only reason.
Click to expand...

Yes, Thanks, I was trying to keep the topic to the mash out step, but this is definitely true, that a lower temp mash will favor beta amylase and produce a more fermentable wort.

I should have stated "One reason for the mash out step..."

also- almost all commonly used malts are "fully-modified" and really just require one single infusion mash at around 150-156 degrees. doing more rests, and lower temperature rests, than that is largely unnecessary unless you are using lots of under-modified malts that require more protein conversion. overdoing it with multiple rests can even negatively impact the finished beer.
Click to expand...

As for this, that modern malts are highly modified, I would agree with this regarding the saccrification rest, but a short protein rest can help with better head retention and mouthfeel. notice my emphasis on short. On the same note though too, it is good practice to do an iodine test a few times during your mash to determine when your conversion is complete. I have found that my mash is complete after 25-30min for most batches (Batches with high % of wheat or rye tend to take longer). So mashing for a full hour may be lending to over mashing.
 
Thanks for all of the responses! I'm going to try a mash out when I brew next week.

I usually do two batch sparges, so when I calculate my infusion volume, I would imagine that I would subtract the infusion volume from the necessary 1st sparge volume, correct?

I also will do a few iodine tests throughout the mash, I've only done these after 60 mins of mashing.

Thanks again!
 
KrazySquirrel said:
I usually do two batch sparges, so when I calculate my infusion volume, I would imagine that I would subtract the infusion volume from the necessary 1st sparge volume, correct?
Click to expand...

yes this is correct.

You might want to check your pH of your mash and especially of your second sparge too. With batch sparging this should not be an issue, but if your water is already fairly basic your pH might be getting high enough to start extracting tannins at this step, leading to the astringence you mentioned earlier in the post.

If you find that your pH is to high, you might want to add some acid malt to your grain bill, or look in to acidifying your mash, and or sparge water.

Best of luck
 

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