Kettle sour with grains

[hopbrad]

I am brewing a kettle sour, added some lactic acid to bring the pH down to 4.3. I only had acid malt on hand and used that for the lacto instead of Pilsner malt. Not thinking that acid malt is sprayed with lactic acid, I am wondering if that process kills off the lacto on the grain husk?

 

[Dgallo]

I am brewing a kettle sour, added some lactic acid to bring the pH down to 4.3. I only had acid malt on hand and used that for the lacto instead of Pilsner malt. Not thinking that acid malt is sprayed with lactic acid, I am wondering if that process kills off the lacto on the grain husk?

lacto is a bacterial strain that creates a low ph environment it’s self. It works til about 3.2. Some wild bacteria and yeast on the grain may be able to work lower. So you really need to boil 10 minutes to insure is sterile.

You were better off pitching lacto or a blend to sour instead of adding lactic acid. And then boiling again when you hit the ph you desire.

 

[hopbrad]

It is beneficial to lower the pH first to about 4.5 which will help head retention but more importantly create a hostile environment for anything that would create unwanted off flavors/aromas...(vomit-y, cheesey, etc). And let the lacto do its thing. It was an impromtu kettle sour. My burner kick the bucket. So figured instead of dumping it. Let it sour for a few days then once the burner is ready, and pH is where I want it...boil and ferment.
This morning I switched out the acid malt with some regular 2-row. The pH did drop to 3.9. But I am not sure if that was from the lacto taking hold or the acid that was on the acid malt.

lacto is a bacterial strain that creates a low ph environment it’s self. It works til about 3.2. Some wild bacteria and yeast on the grain may be able to work lower. So you really need to boil 10 minutes to insure is sterile.

You were better off pitching lacto or a blend to sour instead of adding lactic acid. And then boiling again when you hit the ph you desire.

 

[Dgallo]

It is beneficial to lower the pH first to about 4.5 which will help head retention but more importantly create a hostile environment for anything that would create unwanted off flavors/aromas...(vomit-y, cheesey, etc). And let the lacto do its thing. It was an impromtu kettle sour. My burner kick the bucket. So figured instead of dumping it. Let it sour for a few days then once the burner is ready, and pH is where I want it...boil and ferment.
This morning I switched out the acid malt with some regular 2-row. The pH did drop to 3.9. But I am not sure if that was from the lacto taking hold or the acid that was on the acid malt.

Well your mash should be around 5.4. Low ph hurts head retention actually. That’s the reasoning why many sour recipes call for 30% or more of wheat. After mashing you can drop your ph if you wish. A 4.5 isn’t very hostile. Think about it after you kettle sour and pitch brewers yeast it can still ferment out at 3.2-3.5. The only way to insure a clean kettle sour is boiling it and pitching a proper amount of lacto or other blend so it out comepetes the other microbes. Same if your using Brett or co-pitching

 

[RPh_Guy]

your mash should be around 5.4.

He already did the mash and transferred the wort to the kettle.
He lowed pH, which IS STRONGLY recommended in this case. It helps prevent bacteria off-flavors and does improve head retention by reducing the enzyme activity in the bacteria that degrades foam proteins.
He added some grain which contains wild cultures.

The pH did drop to 3.9.

This shows there there is lactic acid bacteria in your wort, so yes, the acidulated malt had wild bacteria on it.

I hope you're also monitoring the s.g.

 

[hopbrad]

Thanks, I lowered the pH of the wort in the kettle to 4.2 not my mash pH. I couldn't boil since the burner kicked the bucket otherwise I would have. It should be up and running again tomorrow. Since i didn't have a lacto culture on hand I had to use grains and was instructed to lower the pH and keep around 110-120 to make the best environment possible for lacto and not other bugs/yeasts.
Original question is if acid malt can be used in lieu of pilsner malt to grow lacto in the kettle. or if the process of acidify the malt(spraying it with lactic acid) kills the lactobacillus on the husks.

Well your mash should be around 5.4. Low ph hurts head retention actually. That’s the reasoning why many sour recipes call for 30% or more of wheat. After mashing you can drop your ph if you wish. A 4.5 isn’t very hostile. Think about it after you kettle sour and pitch brewers yeast it can still ferment out at 3.2-3.5. The only way to insure a clean kettle sour is boiling it and pitching a proper amount of lacto or other blend so it out comepetes the other microbes. Same if your using Brett or co-pitching

 

[hopbrad]

I ended up adding some regular 2-row today just to be safe and have been topping the kettle off with c02. Hoping things work out. I have not been monitoring SG. I'll do that now.

He already did the mash and transferred the wort to the kettle.
He lowed pH, which IS STRONGLY recommended in this case. It helps prevent bacteria off-flavors and does improve head retention by reducing the enzyme activity in the bacteria that degrades foam proteins.
He added some grain which contains wild cultures.


This shows there there is lactic acid bacteria in your wort, so yes, the acidulated malt had wild bacteria on it.

I hope you're also monitoring the s.g.

 

[Dgallo]

He already did the mash and transferred the wort to the kettle.
He lowed pH, which IS STRONGLY recommended in this case. It helps prevent bacteria off-flavors and does improve head retention by reducing the enzyme activity in the bacteria that degrades foam proteins.
He added some grain which contains wild cultures.

Correct me if I’m wrong here; isn’t there still potential for off flavors? Or does the drop in ph prevent them from producing esters or phenols?

 

[RPh_Guy]

Correct me if I’m wrong here; isn’t there still potential for off flavors? Or does the drop in ph prevent them from producing esters or phenols?

There's definitely potential for off-flavors from both wild bacteria and wild yeast.
Using wild cultures (from grain or anywhere else) is risky and unpredictable, especially in unfermented wort.

However, lowering the pH greatly reduces the risk because it prevents Clostridium growth, and Clostridium tends to produce very nasty flavors and aroma (butyric acid in particular).

Furthermore, there's risk of fermentation from wild yeast, which is why I suggested to monitor specific gravity.

Random FYI: souring with grain is most likely from Leuconostoc, not Lactobacillus.

Hope this all makes sense! Cheers

 

[hopbrad]

SG is the same. 13.5p. pH dropped to 3.78. Will check again in the AM