Avoiding foul sour mash aromas

[technicoloraudio]

It seems to be pretty common knowledge that the foul aromas caused during sour mashing spur from the mash reacting with oxygen from the environment. I have also found countless methods of folks "blanketing" their mash with inert heavy gas or sealing their tun to the best of their ability.

I have wondered if all off flavors and aromas could be avoided by sour mashing under vacuum by holding the mash at incubation temp via a circulating water bath.

I am going to try this experiment next weekend for 3 gallons, but figured I would appeal to those with sour mashing experience for any warnings or pointers.

My plan is to mix 5 lbs of grain (70% Belg pale/30% wheat malt) with 6.25 qts of water and 1/2 oz. of saaz) then vacuum seal it into bags (I will probably split it into 2 or 3 bags). I will control the temperature of the water bath with an immersion circulator used for sous vide cooking. After initial mash at 155°, I will drop the temp to 110° for three days. After that I will drain the bags of the water and grains and pour 5.25 qts of 185° water over the grains to reach full volume and stop lactivity.

I realize this is very unorthodox, but I am very curious as to how flavors would develop under vacuum.

My main concern: will sour mashing create an excess of gas within the bags causing them to burst and destroy my kitchen?




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[ChefRex]

Interesting, what type of sealer do you have? I have a hard time sealing moist foods nevermind a liquid with mine as it pulls the liquid past the sealing strip not allowing it to get hot enough.

 

[bikesandbrews]

This is a fantastic idea. I wonder if putting the mash in something stainless steel or tempered glass could reduce waste? maybe a 10L wide mouthed beaker? It may also be great for creating pitchable packs into a sour mash to immediately drop ph for the lacto to be healthier. you could make 10 and then keep em in the fridge!

 

[metic]

I would definitely be worried about co2 production. Any wild yeasts in your mash will produce it, along with certain strains of lacto.

 

[technicoloraudio]

I have a vacmaster vp215 chamber vac that will vacuum a 10"x15" bag full of whatever.

However, even the chamber sometimes sucks a little juice out if I am not paying attention so I considered freezing the mash in the bags before vacuuming it which would make for the tightest seal.

The lacto starters thing is a great idea, I am getting really excited about this.

Also, I feel like most co2 production would take place during fermentation, which even if any wild yeast survived through the incubation period, there would not be any oxygen available to fuel co2 production.

Who has experience with using lacto starters? If this operation proves successful, I might have to ramp up production for distribution...🍻




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[metic]

My lacotbacillus starters produce a lot of co2 because I'm using a hetero-fermentative strain. If you're relying on the grain to provide you with your organisms, there's no telling what you'll get. One way round this might be to kill anything already in the wort by raising the temperatures up closer to boiling, then pitching a strain of lactobacillus you know to be homo-fermentative.

 

[passedpawn]

If you guys are using the Foodsaver sealers, there's a trick to not sucking juice. Hit the vac button, and as soon as the juice starts getting sucked up, hit the seal button. The vacuuming stops and it seals immediately. Maybe you all knew this already; I had to experiment to figure it out.

 

[dinnerstick]

i was considering doing exactly this, but instead went for sour mash (well, souring wort) in a bottle in my sous-vide bath. i purged the airspace a couple times with CO2 and then left the cap a tiny bit loose. after 4 days at 52 deg the pH was 3.3, and the smell was actually very pleasant.
the strategy that i though of but didn't execute was to fill a vac bag with wort, seal it (not under vacuum), cut a corner, and then purge with co2, and close the lid of my sous vide down on the corner, keeping it closed but providing an emergency exit if gas built up. nah, went with the bottle.

 

[Culbetron]

I just filled a 9 liter water bottle to the very very top with wort, mixed in some grain, stuck an airlock on it and I didn't get any stink, just a good, clean sourness.

 

[technicoloraudio]

Does anyone know of the temp tolerance of 3 gallon better bottles?

Would holding one at incubation temp compromise the plastic?


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[Arrheinous]

If you aren't 'mashing out' that portion before storing at moderately high temps will you get a thinner wort from the continued work of enzymes as the bag cools down to low 150's and 140's for a time?

 

[technicoloraudio]

I was thinking about that which is why I didn't want to do full volume mash and figured I would kill microbial activity with a small "sparge" before pitching yeast. Maybe no?
I know a lot of folk are doing no boil or no chill berliner's but I wanted to see how this worked.
And I became interested in having lactic starters on hand.
And I have been wanting to use my immersion circulator to make beer.


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[Arrheinous]

If you drop the temp to 110 right away then it should be fine. What I mentioned was a concern I've seen for people doing the no chill method for cooling wort overnight.

Plus the wheat content should help add extra body anyway, right?

This project sounds really cool. I'm all for doing some high-tech methods.

 

[chefjaypeek]

I made a sour mash Berliner using a chamber vac sealer and a sous vide water bath. I made the wort without hops, chilled it, pitched a handful of 2-row in and vac sealed it, then put it in a water bath at 110 for a couple of days. I did get CO2 production, the bag swelled, but did not burst (I used the largest bag I had, a 12X14 I think) and it was a 1 gallon batch. I then boiled with a small amount of hops, and pitched US-05. Let it ferment for 2 weeks and then 2 weeks in a secondary. Primed and bottled in 750mL bottles. I tried the first one after 3 weeks, and it was good, but got some "bleu cheese" aroma, but not flavor. I gave away 3 bottles, and heard back from one a few weeks later that they liked it, and it's funk. I still have one bottle with about 4 months age on it now, I think I may have to open it soon and see.

I was intrigued about the results and will try again, possibly trying to build a starter from a smaller batch and see what happens.

Just a fyi for anyone trying to vacuum seal liquids, make sure they are as cold as possible, when a liquid is put under vacuum, it will boil at a much lower temperature than normal, even a room temperature liquid will boil in a chamber vac packer causing the liquid to possibly come out of the bag at the seal bar...

Chef Jay

 

[Arrheinous]

Inoculating with grain is cheap but why not a pure strain or pitching lacto dregs at that rate if you want a really clean sourness? Grain itself can be relatively dirty with other bugs aside from Lacto.

 

[Max_Chavez]

I definitely considering vacuum sealing the Sour mash, as well. However, since I wanted to sour the full mash for a 5 gal batch, it seemed like more trouble than it was worth. I found than blanketing the container with plastic wrap and discharging a few rounds of CO2 via an iSi siphon worked super well. I never had any off or funky aromas, just sweet and sourdoughy. The circulator/waterbath also worked great.
Looks like there might be a few of us from the kitchen into fermenting stuff and making weird beer!

https://www.homebrewtalk.com/f36/first-sour-mash-482533/

Cheers

 

[wingedcoyote]

Ooh, good idea on using the iSi whipper!

 

[signpost]

Am I missing something?

If you have it all sealed up and mash at around 155°F and then just drop it to 110°F, where will the lacto come from? Is the lacto from the grain able to survive through the 155°F mash temp? If so, why do people normally add more grain after the main mash is finished (like I did a few weeks ago)?

Aside from the possible issue of inflating the bags, I just don't understand how it is going to sour without reopening it and adding some form of lacto.

 

[Arrheinous]

From what I've read, wild lactic acid bacteria (but maybe not lactobacillus) can form temperature-resistant spores that will survive the initial heating and then reactivate when it's safe to spread.


I've been experimenting with no boil beers for the last four or so beers (saison, stout, oud bruin, Flander's red). Something I noticed is if you sparge out with 180F water you won't get spontaneous fermentation in what you run-off as long as it's running off hot.

After that hot sparge, when I sparged again with that grain bed with cooler water (below 150F) to get extra wort for starters that separate wort soured. So it looks like the lacto survived high temperatures at 180F briefly during the sparge but died off over time when I left that hot sparged wort to chill slowly in a bucket in a fridge over a few hours.