BIAB Mashing Out

[Oldskewl]

I've just been analyzing my process as I have a year of brewing under my belt. When you mash out, at say 170F, do you leave the grain and bag in the pot as you raise the temp of the wort to the desired mash out temp? I have not been. I pull the bag at the end of he mash, via a pulley, and start heating the wort for the boil as the bag drains. I have not had any fermenting issue, but wanted to get some clarity on this aspect of the brew and what it's benefit it. Thanks!

 

[BowAholic]

I always leave the bag in the kettle until I reach mash out temp, then pull and drain while raising to boil. I have been getting good efficiency/conversion doing this.

 

[Morrey]

I'll probably be offered an opposing opinion, but like the OP, I always lift my grain bag out and squeeze but do not fire the burner til the bag is out of the kettle. Basically I am removing the grain bag at the temp my mash has stabilized at (usually an hour mash) which is typically around 148-149F or close. It's probably safe if you apply heat and keep the bag moving, but I am fearful of the heat on the mesh bag. I'll then immediately start ramping up to the boil as soon as the bag is out.

With that said, I'm sure nay sayers will list enzymatic reasons why I (we) are all wrong. But, this method has worked to produce some exceptionally fine beers for me. I see no reason to change my method since each brewer develops their own signatures which makes brewing fun and unique.

(My efficiency numbers are very good and I attribute this to my BIAB grain grind and properly adjusting my mash water ph and chemistry with no eff% loss from removing the grains at 148)

 

[BowAholic]

I guess I should add that my bag is inside a basket, so I don't have to worry about scorching it when I add heat...

 

[Morrey]

I guess I should add that my bag is inside a basket, so I don't have to worry about scorching it when I add heat...

That is a big advantage for sure!!!!

I have temp probes and dip tubes in the way, but Arbor Fab makes a D shaped steel mesh basket that can take direct heat. Always looked at those but quite spendy!

 

[Oldskewl]

Looks like a split so far. I have never had any efficiency issues not leaving the bag in the kettle. I guess I need to give it a try next time and see if I notice any improvements.

 

[dmtaylor]

Skip the mashout, it doesn't do much if anything and you'll save a few minutes of your life.

 

[Murphys_Law]

I may be wrong but I thought mash out was to stop conversion in the mash tun and basically when we pull the bag we are effectively doing a mash out.

 

[Soyben]

I never do a mash out, I just pull my bag, drain and heat to boil.



The paragraph below may help you from How to Brew by John Palmer

What is Mashout?

Before the sweet wort is drained from the mash and the grain is rinsed (sparged) of the residual sugars, many brewers perform a mashout. Mashout is the term for raising the temperature of the mash to 170°F prior to lautering. This step stops all of the enzyme action (preserving your fermentable sugar profile) and makes the grainbed and wort more fluid. For most mashes with a ratio of 1.5-2 quarts of water per pound of grain, the mashout is not needed. The grainbed will be loose enough to flow well. For a thicker mash, or a mash composed of more than 25% of wheat or oats, a mashout may be needed to prevent a Set Mash/Stuck Sparge. This is when the grain bed plugs up and no liquid will flow through it. A mashout helps prevent this by making the sugars more fluid; like the difference between warm and cold honey. The mashout step can be done using external heat or by adding hot water according to the multi-rest infusion calculations. (See chapter 16.) A lot of homebrewers tend to skip the mashout step for most mashes with no consequences.

 

[Morrey]

I never do a mash out, I just pull my bag, drain and heat to boil.



The paragraph below may help you from How to Brew by John Palmer

What is Mashout?

Before the sweet wort is drained from the mash and the grain is rinsed (sparged) of the residual sugars, many brewers perform a mashout. Mashout is the term for raising the temperature of the mash to 170°F prior to lautering. This step stops all of the enzyme action (preserving your fermentable sugar profile) and makes the grainbed and wort more fluid. For most mashes with a ratio of 1.5-2 quarts of water per pound of grain, the mashout is not needed. The grainbed will be loose enough to flow well. For a thicker mash, or a mash composed of more than 25% of wheat or oats, a mashout may be needed to prevent a Set Mash/Stuck Sparge. This is when the grain bed plugs up and no liquid will flow through it. A mashout helps prevent this by making the sugars more fluid; like the difference between warm and cold honey. The mashout step can be done using external heat or by adding hot water according to the multi-rest infusion calculations. (See chapter 16.) A lot of homebrewers tend to skip the mashout step for most mashes with no consequences.

Soyben I think you provided great information! Personally, I mash with full water volume, so based on what Palmer quoted, I'd have no potential issues with viscosity (too thick mash) or stuck sparges.

Additionally, seems this mashout process is more directed at 3 vessel brewing and not BIAB.

 

[BowAholic]

and I basically just leave the bag in until I get close to the 170 degrees, pull the bag, and continue allowing the wort to heat to a boil. I did make the mistake one time of allowing the bag to stay until it was way above 170... and the beer was very sour and totally not what it should have been... lesson learned and it will not happen again.

 

[singybrue]

A mashout is really only needed for fly sparging.

 

[dstockwell]

Full volume mash, no mashout..

 

[TexasWine]

A mashout is really only needed for fly sparging.

This.... Only needed for fly sparging.

 

[Tribe Fan]

I mash out for 2 reasons:
1. Capacity. I can't fit all of the liquid and grains for a full mash, or it's way to close to chance.
2. The slight increase in temp makes the mash more liquid and in combination with a 2nd squeeze, I would think I would have a better chance of washing out more residual sugars from the grains.

 

[enkamania]

I used to mash out, thinking the raised temp would make it easier to extract the wort. Since I stopped, I have noticed no difference getting the wort out

 

[Sadu]

If you are removing the bag then heating to 170f that is not really a mashout. The whole point is to loosen the sugars that are on the grains, so if the grains are gone already there isn't much point.

Since you are heating to boiling anyway with biab the enzyme conversion gets stopped quickly.

I don't mashout but I do add a sparge to my biab process (called maxi-biab). This got me an extra 10% efficiency and for me is worth doing.

 

[Johow]

My kettle is not big enough for a full volume mash so I usually mash in about 5.5 gallons of water and then heat the other 3 gallons to 170. After my mash I pull the bag and drain/squeeze, then dunk it in the 170 deg water for about 10 minutes before drain/squeezing again and then add to my kettle for boil. When I started doing the dunk, my efficiency shot up by 10 or 15%. Perhaps the mashout temp is not necessary but it sure seems to help my numbers and I can start heating the kettle as soon as I pull the bag.

 

[rhys333]

I get too much heat loss during mash if I use my 10 gallon kettle, so I mash indoors in a 5 gal pot (less headroom and increased thermal mass). Towards the end of the mash I raise 4 gallons to 170 in the 10 gallon kettle and transfer the bag across. I also get the first runnings heating right away to stop enzyme activity and get things to boil quicker. Makes for fast work and good beer.

 

[TexasWine]

I mash out for 2 reasons:
1. Capacity. I can't fit all of the liquid and grains for a full mash, or it's way to close to chance.
2. The slight increase in temp makes the mash more liquid and in combination with a 2nd squeeze, I would think I would have a better chance of washing out more residual sugars from the grains.

I think you might be confused about these two points. My understanding is that....

1. Mashing out, or raising the temperature of the grain bed, has nothing to do with the volume of the mash. Its purpose is to stop enzymatic activity for those who have a prolonged sparge step, i.e. fly sparging. This"locks in" the profile they were shooting for as opposed to ending up with a very fermentable wort. Sparging and mash out are mutually exclusive.
2. The viscosity difference of the wort at 150F and 170F is almost nil. There is no advantage, from a fluid dynamics standpoint, to heating up the grain bed for mash out.

 

[TexasWine]

The whole point is to loosen the sugars that are on the grains, so if the grains are gone already there isn't much point.

Promise I'm not trying to be the accuracy police here, but I'd double check your statement. The intent of mash out is to stop enzymatic activity. It doesn't "loosen the sugars".

The only people that in theory should benefit from a mash out are folks with extended sparge steps. And I've never seen a BIABer that has an hour long sparge.

If a BIABer does see an efficiency bump with a mash out, it is because conversion was not complete before the mash out was conducted.

 

[soccerdad]

No mash out here. Used to .. and thought it got me a couple of points, but realized that I can get those couple of points by just mashing the grains for another 10 minutes without bumping the heat. This was influence from biabrewer and their belief in a 90 minute mash.

 

[kh54s10]

I agree that many are misinterpreting the process of mash out. It is to stop conversion. It has nothing to do with rinsing sugars etc. In BIAB you are going from mash to boil pretty quickly so a mash out step is unnecessary.

It is a technique to lock in a taste profile for fly sparging mostly. In that process where sparging could take an hour, conversion will continue, changing the flavor profile during this long step.

 

[Bobby_M]

I would just add further that it's much easier to squeeze the bag at 150 than 170f. Even with thin gloves, I feel the difference. Also, you are wasting a lot of energy raising the temp of grain you are about to discard. Much faster to boil with grain removed.

 

[pricelessbrewing]

This might upset some people but a mashouts a purpose is NOT to increase efficiency, nor is it to significantly change the viscosity and make rinsing the sugars more effective… A mashout denatures the enzymes and locks in the wort composition. This really only applies in my mind for fly sparging, or other slow sparging methods. If you’re doing biab, or doing a 5-15 minute batch sparge then there’s no need to mash out at all. If you’re reporting a significant efficiency gain from a mashout then the most likely explanation is either due to a second sparge volume increasing your lauter efficiency or that you’re really extending your mash time and not getting full conversion in the original mash time and you’ll benefit as much or more by mashing longer, or crushing finer. However there is a special case here, where a higher temperature increases the activity of alpha enzymes which may further convert starches into complex chains of sugar. These long sugar molecules and dextrins are likely to give a higher fg however, and so I reiterate that you’re better off improving the characteristics of your mash to ensure a quick conversion rate.

tl;dr If you're not fly sparging, don't do it. It's a bandaid that's covering up other issues

My thoughts on mashouts...

 

[johnv51]

I brewed yesterday. I took gravity readings at the end of the mash. I lifted the brew bag off the bottom of the pot and fired the propane burner. When the mash reached 170 F. I turned off the burner and set the sous vide unit to circulate at 170. After 15 minutes I removed the bag, pressed it to get out the wort and checked the gravity again. I gained 10 full points by mashing out. I usually gain at least 5 gravity points. I will continue to mash out as it improved extraction and efficiency.

 

[doug293cz]

I brewed yesterday. I took gravity readings at the end of the mash. I lifted the brew bag off the bottom of the pot and fired the propane burner. When the mash reached 170 F. I turned off the burner and set the sous vide unit to circulate at 170. After 15 minutes I removed the bag, pressed it to get out the wort and checked the gravity again. I gained 10 full points by mashing out. I usually gain at least 5 gravity points. I will continue to mash out as it improved extraction and efficiency.

If your wort gravity goes up during a mash out, that means that not all of the starch in the grain was gelatinized and dissolved in the wort prior to mash out. Your mash was not done. The other possibility is that you inadequately stirred prior to taking the pre-mash out SG sample.

Brew on

 

[johnv51]

The malt mashed for 90 minutes prior to mash out and passed an iodine test. We will agree to disagree.

 

[doug293cz]

The malt mashed for 90 minutes prior to mash out and passed an iodine test. We will agree to disagree.

If the additional SG didn't come from more starch dissolving, then where did it come from? Once everything possible is in solution, the SG does not increase with additional hydrolysis of starches and dextrines (making smaller sugar molecules from larger glucose chains.) Did you include some of the grits in the iodine test, and smash them prior to adding the iodine? Undissolved starch is in the grits, not in the wort. Just because there is no starch in the wort, does not mean there is no starch remaining in the grits.

Brew on

 

[Carolina_Matt]

I brewed yesterday. I took gravity readings at the end of the mash. I lifted the brew bag off the bottom of the pot and fired the propane burner. When the mash reached 170 F. I turned off the burner and set the sous vide unit to circulate at 170. After 15 minutes I removed the bag, pressed it to get out the wort and checked the gravity again. I gained 10 full points by mashing out. I usually gain at least 5 gravity points. I will continue to mash out as it improved extraction and efficiency.

It looks like you pressed to get the wort out after the mashout, but not after the original mash. Is it possible that the gravity change is due to the squeezing?

 

[dwightr8]

I brewed yesterday. I took gravity readings at the end of the mash. I lifted the brew bag off the bottom of the pot and fired the propane burner. When the mash reached 170 F. I turned off the burner and set the sous vide unit to circulate at 170. After 15 minutes I removed the bag, pressed it to get out the wort and checked the gravity again. I gained 10 full points by mashing out. I usually gain at least 5 gravity points. I will continue to mash out as it improved extraction and efficiency.

 

[doug293cz]

It looks like you pressed to get the wort out after the mashout, but not after the original mash. Is it possible that the gravity change is due to the squeezing?

If the mash is "done" and adequately stirred prior to draining, then squeezing will not increase the SG, only collect additional volume at the same SG.

There never is any solid sugar in the wort that needs dissolving. The sugar is created a molecule at a time from starch that is well gelatinized, or already in solution, and those new sugar molecules are in solution when they are created. There are likely to be concentration gradients during saccharification, with higher density (SG) wort near the surfaces of the grits, or in any porosity in the grits.

Brew on

 

[johnv51]

I shared my results. Throwing shade on other home brewers doesn't make this site a more inviting place to visit.

 

[doug293cz]

I assure you, I am not trying to "throw shade." You presented your observations, and the explanations I gave (three separate posts) are totally consistent with your observations.

Brew on

 

[johnv51]

Thanks for your response. I just wanted to share that mash outs work for me.

 

[shetc]

If you scan through the results collected here https://www.biabrewer.info/viewtopic.php?f=51&t=1669, you will see that a mash out can increase OG by a couple of points, on the whole. It does require more time to brew so you have to decide if that is worth the effort.

 

[CarolinaMatt]

My kettle is not big enough for a full volume mash so I usually mash in about 5.5 gallons of water and then heat the other 3 gallons to 170. After my mash I pull the bag and drain/squeeze, then dunk it in the 170 deg water for about 10 minutes before drain/squeezing again and then add to my kettle for boil. When I started doing the dunk, my efficiency shot up by 10 or 15%. Perhaps the mashout temp is not necessary but it sure seems to help my numbers and I can start heating the kettle as soon as I pull the bag.

I do the same exact thing and noticed the same results! Prior to the dunk sparge I was around 70% and now I easily get 80-85% every time.

 

[LittleRiver]

I do the same exact thing and noticed the same results! Prior to the dunk sparge I was around 70% and now I easily get 80-85% every time.

If you have a fine grain crush and a good water profile you should be getting low 80's without doing separate sparge steps.

 

[CarolinaMatt]

If you have a fine grain crush and a good water profile you should be getting low 80's without doing separate sparge steps.

Have not dabbled in to the super fine crush yet -- usually a double crush at the homebrew store. When you say fine do you go as far as flour like?

 

[LittleRiver]

...When you say fine do you go as far as flour like?

I use a roller mill with a .025" gap, and yes there's a fair amount of flour.

Make getting a mill a priority. Your efficiency will increase, and you can buy/store grain in bulk without worry of it going stale, since you'll be able to crush it whenever you need it.