Using pure lacto for sour mash

I'm piecing together a 5.5 gallon sour mash extract & partial mash brew. Instead of pitching a handfull of grains as a source of lacto (& other bugs), I want to use the pure Lactobacillus Delbrueckii strain from White Labs.

My 2.5gal mini-mash will have 1.75 lbs specialty grains & 2 lbs DME. Calculated around 1.044. I know the Lacto will drop this down during the souring period, just not sure how much.

The souring mini-mash will be held ~100 degrees F.

I plan to let the Lacto get munching for a yet undetermined amount of time, add the rest of my DME, bring to a boil & add the rest of my ingredients (hops, whirlfloc, etc).

So, here's where I need more info:

How long should I let this sour? I've noticed 24 hours to be pretty common for the Kentucky Common.

How many points should the Lacto drop this down? The full 5.5 gallon batch should be 1.045 minus what the Lacto munches.

The idea of a sour mash is to introduce lacto by natural means. If you want to sour a beer using lacto, you can add it to your fermenter. By adding it to a mash to sour it like that, you're still going to have the common issues associated with doing a sour mash.

My plan was to use the sour mash method to achieve a moderate amount of sourness then boil to kill off the Lacto. Using the pre-set amount of straight Lacto, with a precise amount of wort, I'm hoping to get a sour mash that can be consistent. Is this sound reasoning?

brandonjonesVW said:

My plan was to use the sour mash method to achieve a moderate amount of sourness then boil to kill off the Lacto. Using the pre-set amount of straight Lacto, with a precise amount of wort, I'm hoping to get a sour mash that can be consistent. Is this sound reasoning?

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Not really. Because you have to consider that there is still other organisms that will possibly set in while doing a sour mash. They're not consistent in the least because you're keeping that temperature up at a place where everything loves to grow. It will likely ending up like sour vomit in a day like that, and the vomit smell does not always subside.

What I would do is work on a method to add the lacto in primary. A set amount of lacto so far in to the fermentation that will allow some of the residual sugars to be converted. Or, even better, separate a gallon, sour it with lacto, and blend back in to the desired taste. A lot of breweries who do sour beers make what is called an "acid beer" that they use to blend in with a beer with no sourness. It gives a great level of control.

Check out this thread (https://www.homebrewtalk.com/f127/fast-lacto-brett-153389/) where I discuss my exploits with a fast lactobacillus fermentation coupled with an all-brett L fermentation.

A few observations:
- My lactic fermentation was done in a cooler and went for 2.5 days, starting at 120F and dropping down to 65F. Unhopped wort.
- Dropped maybe 3-4 points total.
- I would have liked even some more sourness. I think I could have achieved this through either A) making a starter, or B) being able to maintain temps longer (would have needed an additional hi-temp setup).
- The lacto ferment smelled like garbage, but gave a very clean, bright sourness. So I think it was successful.
- I boiled afterwards like you mention to kill the bacteria.
- I'd consider doing the lactobacillus ferment on 100% of the batch, but was afraid of having the hops screw it up.*

*A thought: lambic brewers use lots of aged, low alpha acid hops to retard lactobacillus growth. The bitterness is gone but the hops inhibit lacto. I wonder if bittering with just a tiny bit of super-high alpha acid hops would not inhibit lacto growth, cuz the compounds that fight the lacto would be at low levels. You could use like 0.25oz of warrior and get enough bitterness.

Thanks for the info Sixbillionethans. This is almost along the line I was wanting to take, given a few modifications.

The plan was to innoculate my mini-mash with the pure Lacto and place in a carboy with an airlock. Put it in a water bath set @ 100 degrees F with a submersible heater (possibly fish aquarium heater?) for "X" amount of time. Then boil (with the rest of the DME, hops, adjuncts, etc), cool & ferment with ale yeast.

My intention behind all this is to make a Kriek-style, without using Brett and without waiting a couple years. I planned to "age" some hops in the oven to use in this recipe. Once primary fermentation is over, rack onto 8-9lbs sour cherries in secondary.

carnevoodoo: I have considered doing a 1 gallon lacto ferment to blend later, but I'm wondering if I could get easily repeatable results with the method I described above.

I say go for it and see how it goes then! Brewing is all about discovery, and I dig that.

Subscribed! Your method sounds like exactly what I was going to try next. I'm very curious how it goes for you.

Still in the planning stages for this brew. Funds are tight, I'm glad Christmas is over. For the "sour mash" stage I'm going to use a 3 gallon carboy in a water bath with a couple fish tank heaters & bubbler to keep the water circulating. I've read that most small fish tank heaters have a max temp of 93 degrees F. Hopefully 2 50w heaters will keep me close to 100 degrees F, I'll have to do some testing.

I'm thinking of dropping the recipe volume down to 5 gallons instead of 5.5 gallons. The initial 5.5 gallon was to account for loss when racking off the cherries. I've found some tart cherry concentrate with no sugar added that's roughly equal to 4.5 lbs of cherries per quart. I figure I'll use 2 quarts & that brings me back to 5.5 gallons.

As far as aging hops goes, I've read that putting them in an oven ~ 150 degrees F for 1-1 1/2 hours mimics aged hops pretty well. Anybody have experience artificially aging hops this way?

brandonjonesVW said:

As far as aging hops goes

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Here's my understanding of why I wouldn't bother:
- Lambic brewers need lots of hops to retard any growth of lactobacillus, which plays a limited role in lambic fermentation, and other airborne bacteria.
- Aging the hops strips them of their bittering properties, so brewers can add lots of hops without adding bitterness to the beer.
- It would appear that the anti-bacterial properties of the hops IS NOT related to the alpha acids.
- Guys like Mike Tonsemeire (Mad Fermentationist) don't believe using aged hops provides a flavor contribution.

Here's how I apply this to your situation:
- You're doing a "pure" inoculation of brewers yeast, not a spontaneous one, so you don't need the anti-bacterial properties of the hops. Therefore, you can go ahead and use a fresh low AA hop like Hallertau, Tradition, etc.

I'll be curious to see your posted results. By choosing to omit brettanomyces from any secondary fermentation, you will get a very different flavor profile than some of the fast-lactic beers being produced commercially, which include aging in contaminated barrels. Brettanomyces play a significant role in lambic (and Kriek) fermentation. You'll get more of that "simple" sour character that I've had in Kentucky Commons and some "Olde" English Porters.

theres really no need to use aged hops, in traditionally fermented wild beers that are ambient ferments the large amount of hops are used to keep the nasties at bay while all the good bugs take ahold and make a nice beer

when your pitching known quantities i.e. lacto,brett, any smack pack, this isnt necessary because only the good guys are in there, so all you have to do is bitter with any hop to ~10ibu's

Sixbillionethans said:

Brettanomyces play a significant role in lambic (and Kriek) fermentation. You'll get more of that "simple" sour character that I've had in Kentucky Commons and some "Olde" English Porters.

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I totally understand I won't get the complexity with just Lacto & ale yeast. This is literally going to be a soured cherry wheat ale imitating a Kriek.

I considered using just a little of a low bitterness hop, but there are other flavors attributed to hops than just bitterness. Aged hops have a specific funky/cheesy quality. Since I'm styling this after a Kriek, I figure aged hops would add some complexity that wouldn't be there with just a little low alpha fresh hops.

actually if you use correctly aged hops they shouldnt be cheesy at all, in addition a lambic traditionally has a very extended boil to help reduce the volume and it helps in reducing any off flavor from the hops

Cheesy hops are not a extra layer of complexity in a lambic they are a flaw

I see your point. I was off on a tangent anyways regarding aging the hops. I was planning to use 1/2oz Czech Saaz (3% AA) for this brew. That puts me under 5 IBU.

This will have a 90 minute boil. 1/4oz hops @ 60 min & 30 min.

Results?