Sour mashing.

[philm00x]

I'm currently collaborating with jimjohnson on a recipe that will involve souring the beer. Traditionally, the method involved is a sour mash, and it's not something that either of us have done before. For any of the Borg that has taken on this task, how do you go about it? I suppose the most difficult thing for us is finding a heat source to maintain the temperature for such an extended period of time. One site I came across stated that a prolonged rest at around 120-130*F for 12-15 hours should provide a good amount of lactic acid in the wort, and one can just let it go for longer if more sour is desired after tasting a sample. Any input, advice?

[christler]

http://m.youtube.com/watch?v=ohhXiKwYYsg this might help. if you haven't already seen it. Can't remember how they held the temp though and don't have time to watch it.

[Brewbirds]

What about the stuff they use under chafing dishes? "Sterno" I think it is called.

[BigPapaG]

Hey Phil,

In 'Brewing Classic Styles', Jamil Zainasheff talks about three methods for souring a mash...

1.) You can simply add lactic acid. This method is quick and easy and allows you to control the amount of sourness in the beer. The bad (maybe good?) news is that the amount of sourness won't change over time. He goes further to compare this technique as being akin to microwaving a steak... Fast and easy yeah, but much better results an be had by grilling!

2.) A second method that is a lot less controllable, is to throw a handful of grain in the wort and let the wort sit at about 100*F for a couple of days. Due to the populations of Lactobacillus (and other bugs) that are generally present on grain, you will end up with what Jamil describes as a 'sour, aromatic soup'. Once you boil the wort, the souring action stops by killing off the bugs, leaving a fixed amount of sourness. Note that this will add both the lactic acid from the Lactobacillus, but also 'other' flavors. He says, "If you are lucky, the beer can be fantastic. If you are not lucky, at least the snails seem to enjoy it."

3.) How about just adding a commercial Lactobacillus delbrueckii culture from one of the major yeast labs? Just pitch it with your normal ale yeast. The main flavor will come from the wild yeast strain and will be lactic sourness and some other fermentation derived flavors. This is probably the most desired method.

[The_Professor]

I make my own sour malt from barley.

I ground up one pound of barley, put it in a large ziplock bag and add enough water to moisten the barley, mixing it well. The I rolled up and sealed the ziplock bag, wrapped it in a towel, and stuck it in a closet. 5-7 days later, it is ready to be dried. Make sure the aroma is sourish rather than stinky (lacto rather than clostridium). Dry it in an oven at 100 for 24+ hours. Age it for a week or two and add it to the mash.

That added a nice sour flavor to a 3 gallon batch of Kentucky Common.

Not only do I intend to make that again, but to try the sour malt in some other styles. The idea is from a YouTube video I saw about making African millet beer.

[philm00x]

A Kentucky Common is what we're working on. A lot of our concern is basically sacrificing equipment from brewing it so that it becomes "Sour brews only" equipment. Will acid malt or sour mashing lead to this, the way that adding bugs would? Or is it a little more subdued than direct innoculation. The plan so far seems to be to sour mash half of the total grain, and add the resulting wort to the sweet wort from mashing the other half. Not entirely certain how sour things would turn out so we don't wanna go all out (yet).

[philm00x]

What about the stuff they use under chafing dishes? "Sterno" I think it is called.

That actually seems like a really good idea! Thanks!

[BigPapaG]

Sour mashing is gonna be Lacto, so yeah, consider it bugs...

However, good sanitization on anything stainless or glass will be fine...

Plastic however, might want to isolate what you use to wild yeast strains only.

[philm00x]

That's what I figured. Maybe this would be a good time to look into buying a refractometer so I can take smaller samples and so I don't have to sacrifice my sample tube.

[The_Professor]

The Kentucky Common I made had a hint of raspberry between the sour malt and crystal malt. I really liked it.

[philm00x]

Something else I'm curious about, as far as the sour mash goes- must you add unmilled grain to the mash to introduce lactobacillus, or will the milled grist provide lactobacillus on its own?

[BigPapaG]

In the case of the method of innoculating a batch with grain, it could be milled or not...

But remember, it isn't going in the mash... (the heat would kill it)

How I understand it is that the mash and sparge is over at that point...

It goes in the wort which is then held at around 100*F for a period that is long enough to allow the Lactobacillus to flourish and sour the wort...

Once sufficient sourness is achieved, then the wort is boiled and hopped as normal.

[philm00x]

Right. My method was going to be to mash half or three quarters of the grain bill as normal @ 150*F. Then I would cool the mash down to 110-120*F and add the rest of the grain bill so that it could begin souring. My concern is if the milled grain wouldn't have viable lacto on it because of it being run through the mill and crushed (and my reason for having this concern is because I've come across several pages where the sour mash is initiated with unmilled grain instead of with a portion of the grist).

[BigPapaG]

Hmmm... If it were me, I think I would leave a handful or two of grain whole, mill and mash the rest...

Then toss in the remaining whole grain... Easier to rack off of later...

But again, this is a hit or miss process anyway so YMMV.

[mashani]

Hey Phil,

2.) A second method that is a lot less controllable, is to throw a handful of grain in the wort and let the wort sit at about 100*F for a couple of days. Due to the populations of Lactobacillus (and other bugs) that are generally present on grain, you will end up with what Jamil describes as a 'sour, aromatic soup'. Once you boil the wort, the souring action stops by killing off the bugs, leaving a fixed amount of sourness. Note that this will add both the lactic acid from the Lactobacillus, but also 'other' flavors. He says, "If you are lucky, the beer can be fantastic. If you are not lucky, at least the snails seem to enjoy it."

This is what I did for my sour cherry pseudo-kriek What I did is to start giving it little tastes after it sat overnight until it had a level of sourness I was happy with. You do have to remember that it's still sweet (and sour LOL) wort at that point and it will seem *a lot more sour* once it's fermented out, so you have to get used to judging this by experience. If you've tasted bittered sweet wort and have a grasp on how much that bitterness translates to the finished product then you have an idea of how that works, although sour is not apples to apples.

Also be careful with the bittering hops in any soured beer. I used 12IBUs of noble hops in my Pseudo-Kriek and it's plenty. It is probably really only like 8-10 as my hops were not totally fresh.

Doing it this way gives you a bit more complexity then using acidulated malt or lactic acid or tossing in a big blob of pure lacto culture... because more bugs are involved for a longer time. It's still not the same as a real sour beer by any means, but it's as close as you will get without spending a year.