Boiling grain and avoiding tannins

[Utrechtbrew]

Hello people. I'm a brewer at a think tank where we use brewing byproducts to tie into other projects that are in the works. That is the reason I'm asking this question, I would normally not practice this technique. we need to perform the boil with the grains still present, we don't lauter until after the boil. By being the brewer and working within these constraints it is my job to eliminate the tannin/astringency issue this can cause. I know temperature and PH are the drivers for tannins but we all know a decoction emulates some of this principle with no issues. Below are ideas that I have. Please chime in, appreciate any help!

1. Mash/boil very thick to emulate a thick decoction pull
2. Don't boil specialty grains, only base malt
3. Adjust PH to compensate

 

[doug293cz]

Hello people. I'm a brewer at a think tank where we use brewing byproducts to tie into other projects that are in the works. That is the reason I'm asking this question, I would normally not practice this technique. we need to perform the boil with the grains still present, we don't lauter until after the boil. By being the brewer and working within these constraints it is my job to eliminate the tannin/astringency issue this can cause. I know temperature and PH are the drivers for tannins but we all know a decoction emulates some of this principle with no issues. Below are ideas that I have. Please chime in, appreciate any help!

1. Mash/boil very thick to emulate a thick decoction pull
2. Don't boil specialty grains, only base malt
3. Adjust PH to compensate

If your mash pH is in the correct range (5.3 - 5.6), there should be no problem with tannin extraction. You might as well go for a full volume mash, because if you are going to lauter after boiling, there is no gain to doing any kind of sparge. A thinner mash will convert faster than a thicker mash (ref: http://braukaiser.com/wiki/index.php?title=Understanding_Efficiency#Mash_thickness.)

Brew on

 

[Utrechtbrew]

Thanks for jumping in. Don't you think the heat will extract the tannins also or should that not matter?

 

[doug293cz]

Thanks for jumping in. Don't you think the heat will extract the tannins also or should that not matter?

Takes both heat and pH above about 6. You have to worry about tannin extraction with sparging if you have alkalinity in your sparge water, which can raise the diluted mash pH above 6. In the mash, the pH is held lower by the buffering power of the malts, and if you don't add alkalinity, it won't increase by itself.

Brew on

 

[giraffe]

In a decoction, when the grain is boiled, more unconverted starch is broken out into solution as the grain is cooked. . If you boil the whole mash, there wont be any enzymes to break down this last starch. In a traditional multi-decoction mash, the last decoction to mash out is pulled very thin, so this doesnt happen.

Somehow you will need to deal with that.

 

[Gavin C]

Can't be done. You just boiling the whole mash and adding hops in while it boils you won't end up with anything resembling beer.

I would guess it will be a thick gelatenous starchy porridge like mess after an hour of boiling. The normal reactions that occur in a boiling wort will be impacted by the presence of the grain.

Of course I'm only hypothesising here. I've not boiled a full mash for an hour and added hops while doing so.

I think you're trying to square the circle here I'm afraid.

You will of course end up with a liquid that is seperable from the goo but resemble wort to result in beer, it will not.

 

[agrazela]

I agree with doug that so long as pH is in the right <5.6 range, tannins should not be (as much of) a problem.

...we need to perform the boil with the grains still present, we don't lauter until after the boil...

Will this be after some mash time? At least the enzymes will have worked on the extracted sugars. I think Gavin's right though, you'll get some really cloudy, maybe gooey stuff if you boil all the grains in the wort after the mash.

But why does this constraint exist? Are you designing some kind of compact all-in-one home system, or are you designing a (compact?) commercial brewery? Or what?

 

[Utrechtbrew]

I agree with doug that so long as pH is in the right <5.6 range, tannins should not be (as much of) a problem.



Will this be after some mash time? At least the enzymes will have worked on the extracted sugars. I think Gavin's right though, you'll get some really cloudy, maybe gooey stuff if you boil all the grains in the wort after the mash.

But why does this constraint exist? Are you designing some kind of compact all-in-one home system, or are you designing a (compact?) commercial brewery? Or what?[/QUOTE

Thanks everyone for helping here! I guess I should let you know exactly what is trying to be accomplished because there may be other ways around the issue.

Yes, we will perform a standard mash first.

The group uses the spent grains to grow mycelium on for insulation panels. They can't grow mycelium on grain that has any lactobacillus present hence the sterilization/boiling of wort. Now, before you chime in too quick I know that Lacto can be killed easier than in a 60 minute boil but I believe they are looking for a more complete sterilization (I only got a brief 15 min overview so I don't have the complete picture yet.)

I will have to do a no sparge batch so I will have a very thin mash to begin with.

 

[chickypad]

Why can't you mash and drain our your wort then sanitize the spent grain with heat in some way? Otherwise it sounds like a big mess. Like Gavin said, seems like it would certainly interfere with the hop additions.

 

[agrazela]

Why can't you mash and drain our your wort then sanitize the spent grain with heat in some way? Otherwise it sounds like a big mess. Like Gavin said, seems like it would certainly interfere with the hop additions.

Agreed.

Thinking like a BIAB'er: mash as usual, pull/drain/squeeze/pour-over sparge the bag, make beer as usual from those "first runnings"--then dunk the bag of grains into a separate pot of (near?) boiling water for as long as you think you need to "sterilize" the grains for your fungal fun.

(I'm sure that process can be adapted for all those still using antiquated non-BIAB techniques)

 

[BLuck]

I'm not very experienced with all-grain techniques but wouldn't mashing at 145+degF for an hour essentially pasteurize the grain anyway? Or even raising to mashout temps of 168-170 for 15 minutes finish the process? You don't need to raise to boil as pasteurization is time and temp dependent. But this is dependent on need for greater sterilization, which I didn't think is needed for lactobacillus.

Otherwise, I would agree to just get your wort from the mash and then handle the grains.

 

[Gavin C]

I'm not very experienced with all-grain techniques but wouldn't mashing at 145+degF for an hour essentially pasteurize the grain anyway? Or even raising to mashout temps of 168-170 for 15 minutes finish the process? You don't need to raise to boil as pasteurization is time and temp dependent. But this is dependent on need for greater sterilization, which I didn't think is needed for lactobacillus.

Otherwise, I would agree to just get your wort from the mash and then handle the grains.

No

It's an easy thing to test.

Put your spent grains in a bucket and leave them undisturbed for a while. In a day or two take a great big lung filling whiff if you can. Plenty of funk inducing microbes present.

Save yourself the bother of the bucket and dump them on the flowerbeds in a pile. Next day or so (sooner if it's hot) you'll get the smell when you walk by your house.

Ripe.

 

[BLuck]

No

It's an easy thing to test.

Put your spent grains in a bucket and leave them undisturbed for a while. In a day or two take a great big lung filling whiff if you can. Plenty of funk inducing microbes present.

Save yourself the bother of the bucket and dump them on the flowerbeds in a pile. Next day or so (sooner if it's hot) you'll get the smell when you walk by your house.

Ripe.

Good to know, but then makes me think if that is new, post-mash infection (spent grains certainly seem like a favorable medium for growth, as is their use). And also, he specifically called out lacto so was aiming more on that side as a non-spore producing bacteria. But this is all just thoughts from general microbology coursework over a decade ago so I may be missing plenty.