Kettle souring and sugars remaining?

[kererubrewing]

We're looking at producing some kettle-soured beers. It seems a fairly safe way to utilise lacto in the brewery, but one thing which is baffling me is how to get the right starting sugars to achieve a given ABV. Specifically how much sugar will the lactobaciilus consume? Are there any standard guidlines to work to?

[dandan]

After acidification by Lactobacillus heat up the worth to kill bacteria, check gravity and add missing sugar to achieve right ABV.

[J&B]

After acidification by Lactobacillus heat up the worth to kill bacteria, check gravity and add missing sugar to achieve right ABV.

If the question is how much ABV the beer will have it might be more difficult depending on method of souring unless you check alcohol by any other method than pre and post ferm gravity? Hetro- or homofermentative strains of lacto? If you use souring by inoculating with malt it might be hard to know what strains you have. If you use a specific culture it might be easier. I've given this some thought myself but not sure I've come up with a good answer. Lacto seem more difficult than I thought.

[dandan]

Homofermentative species like L.delbruckii produces only lactic acid, heterofermentative species like L.brevis produces except lactic acid, many more acids and alcohol but it`s level is insignificant. Breweries produce kettle-soured beers, using acid malt (hetero Lactobacillus sp.) to acidification the worth and I never have heard that anyone has had a problem with it. So, for example, if you made beer with a bit higher level of alcohol, your customer will definitively not angry with you

[Bainbridge]

Hey Chris,

Wondering if you've brewed it and have any data yet? Been meaning to do one myself but it's Summer here and that means "Hey everyone, you know we make more than just IPA and Kolsch right? Anyone? No? Ok I'll go brew more..."

Cheers
Russell

[OurMutualBrewer]

We brew kettle sours at least once a month. It works GREAT. I have not actually measured how much sugar is lost, but we are brewing one this week and I will make sure to let you know.

[sdbrewer18]

Those of you doing kettle sour beers, how are you determining what size of a lacto pitch to add to your kettle?

Thanks

[AnthonyB]

We have done 300mL of pitchable volume for every barrel we are souring, so for a 7 BBL batch, we will dose the kettle with 2L of lacto from White Labs. Keep in mind the strain will have an impact too. L. Brevis seems to be very hearty while the batches of L. Delbrueckii I have used seem to be much more temperamental. With this dosing rate, we get full pH reduction within 48 hours.

[kererubrewing]

As a follow up:
We used malted Pilsner malt as an inocculant with good success. There is a long lag time and patience is needed.

Sugars consumed were minimal, but the resulting wort was extremely fermentable and terminal gravity was lower than expected by nearly 20%.

[Alphaacid]

Has anyone tried using something like a Roeselare 3763 blend in the kettle? I'm wondering if you could get any Brett character in there or if it takes a lot longer to work then lacto.