Wort souring adjustments

[tarmenel]

Hi there,
I've been trying to sour my beer's pre-boil using wort souring. Then I coil and add the hop's required.
I have a few issues. The first is that the gravity drops quite a bit in 36 hours so how should I adjust for this? The pH really does get down nicely too. The thing is I'm not really picking up this souring after the boil and fermentation.

 

[505-Brewer]

Hi there,

I've been trying to sour my beer's pre-boil using wort souring. Then I coil and add the hop's required.

I have a few issues. The first is that the gravity drops quite a bit in 36 hours so how should I adjust for this? The pH really does get down nicely too. The thing is I'm not really picking up this souring after the boil and fermentation.

What are you souring with? Do you have any metrics (pH, gravity readings) as a more specific example? Perhaps its just tart and not really sour preboil? How long are you boiling for?

 

[tarmenel]

I measure the pH with a meter so I know it's getting sour based on acidity. Using a sourdough yeast that I built up. Been working really well. My problem is with the gravity that is going down to low by the time I start the boil.

 

[MVKTR2]

My problem is with the gravity that is going down to low by the time I start the boil.

I don't understand what you're communicating. Are you saying for instance the gravity might be 1.050 right after the mash when you decide to start souring and the gravity drops to X? across the 36 hours you're sour mashing?

What I'm thinking is toss the pH meter and go with your senses of smell and taste. Additionally if you may be under-innocculating the beer with a sourdough starter. Maybe go with the more familiar homebrew method of innoculation with whole base grains at about 1/2 lb per 10 lbs mash grain volume. If you insist on going with the sourdough starter then try using more of it.

 

[tarmenel]

Sorry if I'm not explaining my process correctly. I'll write down my step by step in hopes this helps.

1. Add strike 13.2 liters of water at 73C to mash tun along with one campden tablet and 2t of citric acid
2. Added grains and gave a vigorous stir. Temperature at 68C with 4.9 pH
3. After 90 minutes poured mash into pot for boiling. 5.4 pH with gravity of 1.042
4. Boiled for 15 minutes and then cooled down to 50C. 5.3pH with gravity of 1.042
5. Pitched lacto yeast from sourdough starter
6. 36 hours later start boil. 4.4 pH with gravity of 1.020

As you can see the last line is where I'm having issues. Maybe there is too much yeast in the sourdough starter and it chews's through the simple sugars or I'm souring too long.

 

[madscientist451]

Sorry if I'm not explaining my process correctly. I'll write down my step by step in hopes this helps.

1. Add strike 13.2 liters of water at 73C to mash tun along with one campden tablet and 2t of citric acid
2. Added grains and gave a vigorous stir. Temperature at 68C with 4.9 pH
3. After 90 minutes poured mash into pot for boiling. 5.4 pH with gravity of 1.042
4. Boiled for 15 minutes and then cooled down to 50C. 5.3pH with gravity of 1.042
5. Pitched lacto yeast from sourdough starter
6. 36 hours later start boil. 4.4 pH with gravity of 1.020

As you can see the last line is where I'm having issues. Maybe there is too much yeast in the sourdough starter and it chews's through the simple sugars or I'm souring too long.

Your "sourdough starter" is causing your problem. Either pitch a commercial lactobacillus made for brewing or use one of the methods in this
article: Good Luck!

http://www.themadfermentationist.com/2013/11/sour-experiment-1-two-week-sour.html

 

[MVKTR2]

Your "sourdough starter" is causing your problem. Either pitch a commercial lactobacillus made for brewing or use one of the methods in this
article: Good Luck!

http://www.themadfermentationist.com/2013/11/sour-experiment-1-two-week-sour.html

^^^^Correct^^^^^
I was going in the opposite direction, wrongly.

 

[tarmenel]

Thanks. I don't have access here to commercial lacto but will try and get something else up and running

 

[Agate]

You're not limited to lacto cultures from a commercial yeast lab. You can use the lacto from yogurt, sour cream, probiotic pills (my favorite) and drinks, kefir, pickle brine, you name it. Anything with active cultures is a likely source of souring bacteria.

 

[tarmenel]

This is why I was trying my luck at the sourdough starter. Seems though there is way to much yeast in there from the sourdough starter itself, something I want. I'll try creating something with yogurt or kefir.

 

[berebrando]

This is why I was trying my luck at the sourdough starter. Seems though there is way to much yeast in there from the sourdough starter itself, something I want. I'll try creating something with yogurt or kefir.

This is correct exactly. There are way too many microorganisms in a sourdough starter. Yogurt would be a good source of lacto.

You can check out this page for some other options: http://www.milkthefunk.com/wiki/Alternative_Bacteria_Sources

 

[505-Brewer]

Use 2row or pilsner
Malt to grow up some lacto. Should be able to get mostly lacto w less yeast. Sourdough is known to have lacto and yeast. Both tolerant of high temps.

 

[tarmenel]

Made a starter last night. I can only get the temperature up to 35C at the moment but used yogurt as my inoculation source.
Just to be clear, I shouldn't see any real activity in the starter correct just CO2 being blown off through the airlock?

 

[Agate]

You really shouldn't see any CO2 being produced at all. Even heterofermentative lacto do not produce noticeable amounts of CO2. Give it a few days and then either taste it or check pH if you have a meter. It should be noticeably tart.

 

[tarmenel]

Oh!!
I thought I'd see some action going on. Well in that case I'll just leave it till Friday when I will sour the wort.
Thanks. I'll update and also try get some photo's

 

[Agate]

Did you make note of which cultures were in the yogurt you used?

 

[tarmenel]

No idea. I just know that it says bio on the yogurt and has live cultures. Not sure which. Is that an issue?

 

[Agate]

No, just curious. Most brands over here list the species of their active cultures.

 

[tarmenel]

The joys of working in the first world

 

[mitchard]

A pH of 4.4 after kettle souring is still really high. You should really see more of a drop in pH before going back to a boil if you want any sort of detectable tartness. Maybe let it ride for 2-3 days. Some strains of lacto don't perform well at lower temps, while strains like Plantarum (Found in many probiotic pills and drinks, including Goodbelly which has a great track record) do very well sitting at room temp (70f or so).

As recommended, i'd go with a pure lab culture, or try the Goodbelly route. I had my recent Berliner hit 3.25 pH after 72 hours with the Goodbelly, and the final product turned out pretty well.

On the gravity note, you shouldn't see much of a drop during kettle souring. Preferably no drop. If the gravity is cutting from 1.042 to 1.020 in 36 hours, you definitely have a Saccharomyces contamination or something. I haven't used a sourdough starter before, so maybe something else is going on in there. There is no way lacto would ferment it out like that.

 

[tarmenel]

It must have been the other yeasts in there. I have now added the lacto starter to my Berliner that I made. I'll see how it turns out. I pitched it and then waited 7 days before pitching the yeast to give it a good chance of souring. I used yogurt as a source and it worked out well in the end. Will also try grains and maybe kefir. The yogurt is pretty easy though.