Tweaked my Mash Process- Interesting Foam Observation

[micraftbeer]

I've been reading a bit about LODO processes lately. I already do closed transfers into purged kegs, but I haven't paid any attention to the hot side really. Keeping in mind minimizing oxygen pickup, I changed from using this Brewtech vourlaf attachment during RIMS recirculation to using a Blichmann Autosparge arm on my batch I brewed today. With that, it had the recirc hose laying on top of the mash, with the hose just below the water level. With the Brewtech vourlaf attachment, I would typically fill up the headspace in my mash tun with lots of light, airy foam during recirc. With the Autosparge, I didn't get any of the foam (expected).

Once it was in the boil kettle, the hot break foam that formed right when coming to a boil was a noticeable pure white. I saw @Bassman2003 reference the hot break foam color when he was doing an experiment to compare the effect of process on hot side aeration.

After the boil, and chilling my wort, I was doing my usual process of pumping the wort to my fermentor through my strainer to catch hop debris. And at this point, I got lots of the airy foam I usually see in the mash when I was using the vourlaf attachment.

So I was curious if anyone had a physical explanation behind the coloring of the hot break as an indicator of HSA during mashing? And any thought or experience of the foam that I saw when transferring to the fermentor?

Not really a problem I'm trying to solve here, just trying to understand the observations I've had.

 

[schmurf]

I haven't an explanation but things that oxidise usually darkens, liquid or solid.

 

[Bassman2003]

Glad to see you are noticing differences in your hot break foam. I can not quote the science off hand, but agree that the white represents the lack of staling processes taking place. Micraft, you are at a good crossroads here. The end goal of low O2 brewers is to retain as much malt flavor as possible. There are mainly two ways to judge this: foam color and amount & taste. If you are interested in going further, I would recommend two more simple steps: Remove the Oxygen from all of your strike water (YOS method on my YouTube channel) and adding some sulfites to the strike water to limit initial oxidation.

The goal is to keep the flavor that is lost within the first 5-10 minutes of the mash. The oxidation happens quite quickly and the awesome malt flavors go away. So everything past this point like limiting splashing etc... only makes a flavor difference if the initial reactions are dealt with.

 

[WalletHocker]

IMHO...

Mash foaming would tend to indicate how much gas is in the mash water and how much air is in the grain bed.

Preboiling or yeast oxygen scavenging would eliminate most oxygen from the water but their may still be small quantities of other lesser gases dissolved in the strike water. Underletting the grain bed pushes the air up and out of the grain bed as opposed to dumping air filled scoops of grain into the strike water which would dissolve more oxygen in the water.

When a low oxygen strike water is combined with an underlet grain bed their is very little air which will bubble out of the mash and create foam. Because their is such a small amount of air it will only pickup microscopic particles creating a constant color looking foam (with no roasted grains it will look whitish with darker grains it will darken but will still be "smooth").

Doughing in with large amounts of gas in the strike water and large quantities of air in the grain bed will give the mash the capability to release larger air bubbles which then have the capacity to bind much heavier proteins bringing those to the surface and creating the dark brownish streaks or blobs of proteins and teig.

How much of the air and gas is released depends on how much the mash is stirred. Not stirring an underlet mash and allowing recirculation to evacuate the remaining air and gas is probably ideal and shouldn't create much foam especially if their is a mash cap with an inch or so of wort riding on top of the mash. It would also keep more of the heavy proteins and teig in the mash tun during lauter.

In the boil, hot pockets of water vapor form on the surface of the boiling vessel and bubble up. Hot break foam is formed when proteins in solution are bound in these water vapor bubbles and rise to the surface where they eventually sink and coagulate (over and over) becoming too heavy to bind with the water vapor bubbles and eventually the foam disappears. The color of the foam depends on the size of the proteins being bound. A good mash lauter will certainly leave most of the heavier proteins and teig in the mash vessel leaving only the small particulate behind. As with the mash these smaller particles create a smooth, constant color foam, the color of which depends on the roast level of the grains used.

Other things that affect the color of the foam is the size of the crush, the quality of the malt used (protein content), and the pH of the wort.

 

[micraftbeer]

@Bassman2003 , yes I meant to add detail that I did use K-meta in preparing my strike and mash water the night before. That was already part of my process to deal with Chloramine from my filtered tap water.

I looked at your info (or your link to someone's) about the YOS. It initially sounded like crazy talk, but when I looked at the details of just adding an amount of bottling/priming sugar and bread yeast based on the volume of water, it really seems like a small addition to what I'm already doing with brewing salts anyway. Again, I prep my water the night before, since I use my BrewCommander controller to heat my strike water while I'm still in bed.

 

[micraftbeer]

Preboiling or yeast oxygen scavenging would eliminate most oxygen from the water but their may still be small quantities of other lesser gases dissolved in the strike water. Underletting the grain bed pushes the air up and out of the grain bed as opposed to dumping air filled scoops of grain into the strike water which would dissolve more oxygen in the water.

This leads me to two questions. And I'm guessing they are probably more about people's feelings and intuition rather than science and data, but that's OK.

Q1: You mention oxygen scavenging eliminating "most" of the oxygen. What's the thought of using the purity/color consistency of the hot break foam in the boil kettle as a measure of how effective the mash was at keeping oxidative reactions minimized? Using my K-meta in strike and sparge water the night before, and then recirculating using the AutoSparge made a huge difference in my hot break. I'm wondering if I could use that to measure how successful my mash was.

Q2: At risk of hijacking my own post into talk of underletting, I haven't thought up a good underletting process that doesn't make my brew day more complicated than I want it. It's a huge time saver, and brew day enabler to use the timer on my BrewCommander and have the strike water in my mash tun start heating while I'm still sleeping. I then get up, pour in the grain while stirring (which I can do without frothing/aggressive splashing). If I underlet, I'd have to heat that water in a separate vessel and pump it over, which is more logistical shenanigans on a groggy just-awoken morning. Any feel for how much contribution the underletting makes? I suppose I could conduct my own experiment with a taste trial or something.

 

[WalletHocker]

What's the thought of using the purity/color consistency of the hot break foam in the boil kettle as a measure of how effective the mash was at keeping oxidative reactions minimized?

IMHO...

The nature of the boil kettle hot-break would be more a measure of how successful your lauter was. Were you successful in leaving the large proteins and teig in the mash tun? You might be able to relate that back to oxidative reactions by then knowing that you didn't disturb the grain bed or over stir the mash or recirculate too fast, etc...

Minimal mash foaming would definitely relate back to oxidative reactions and of course underletting is a part of that equation. O2 free strike water, underletting, recirculation with mash cap and O2 scavengers (AA, KMeta, BTB) all work together. I can't estimate how much one would undermine the others if left out.

The grain crush, malt quality and pH all being equal.

 

[Bassman2003]

Great thread going here. I wish I had done a lauter process + HIDO brew in my 4 batch comparison video! Imho, everything plays a part in getting minimal levels of pure white foam clear of junk. Just taking the O2 away, underletting and adding sulfites reduced the foam and junk in the foam, but it did not eliminate it. A multi-vessel setup is needed to keep all of the undesirable elements left behind in the mash tun.

In my 4 batch test, the beer with water treatment for O2 and just quickly lowering the bag down into the YOS water was my 2nd best tasting beer out of the four. So there is much improvement to be had in your beer even if you can not underlet or lauter. This is my opinion but compared to the HIDO beer, a lot of the overhead was missing.

I know, the YOS method seems like crazy talk when you first hear of it but it just plain works.