Taking pH measurements when kettle souring.

[BrewDawg79]

Attempting my first berliner weisse, and it's currently kettle souring at 105 F. I plan on monitoring pH with pH meter; however, I am unsure of the best way to get the best measurement. Do you stir the souring wort prior to taking the measurement? I would assume so, but a everything I read says to keep oxygen out. Would stirring mess it up? Am I over thinking this? What's your preferred method?

Thanks.

 

[Double_D]

I thought I saw one just like this the other day. Don't know if it got answered but my guess is to pull a sample without disturbing it to much. When I sample my sours I don't stir them.

 

[pricelessbrewing]

I would assume so, but a everything I read says to keep oxygen out. Would stirring mess it up? Am I over thinking this? What's your preferred method?

Thanks.

Aciditiy isn't usually gradient like the way wort gravity is. It's usually homogenous (the same) throughout the wort. No need to stir.

The whole "keep oxiygen out" thing is depending on the method of souring. Lacto doesn't really care if there's oxygen or not, it's going to do it's thing regardless. So if you're pitching a pure lacto strain, it doesn't matter.

The biggest reason to keep oxygen out is for when you're souring with an unusual source, like innoculating with grains. There's a wide array of microbes in there, and preacidification (adding lactic/phosphoric acid) to the wort to get it down to 4-4.5 ph, and eliminating oxygen goes a long way to reducing the likelihood of something undesirable getting in there and fouling up the batch.

 

[BrewDawg79]

Great, thanks. That matches what I have ended up doing. I have taken two pH readings thus far by pulling small samples from the ball valve of the kettle - no stirring. My reptile heating pad wrapped around the kettle (attached to temp controller) is holding the wort at a steady 105 and pH seems to be dropping, but pretty slowly. I'll check again when I get home from work. I think I have finally caught the sour bug; seems like a whole new world of brewing just opened up to me.

Thanks again.

 

[pricelessbrewing]

What did you use to sour?

 

[BrewDawg79]

A pack each of WLP677 and Wyeast 5335. No starter (wish I would have, though). Got lazy.

 

[pricelessbrewing]

Wyeast recommends 90F for 5335, and 677* works best at 85-95 as well.

http://www.milkthefunk.com/wiki/Lac...acillus_strains_and_their_pH_change_over_time

*677 is pretty well known to not be a very effective item. They (white labs) were plagued with yesat contamination in their lacto strains for a long time, moreover delbrueckii doesn't sour very much (recorded PH of 4.3+).

Here's the "official" guide to pitching 677 according to MTF group. You may, or may not be able to view it. https://www.facebook.com/photo.php?fbid=1019344988088974&set=gm.1212529818775230&type=3

 

[BrewDawg79]

I have seen that info on MTF. I have also seen many posts from brewers that claimed success with these strains at temps over 100. We'll see.

Most recent pH reading was 3.9 down from 4.6ish in 48 hours. Gonna let it go another 24 hours and see how much more change I see. If not much more, do you think I can add a couple tablespoons of nonfat yogurt to promote more souring?

Thanks.

 

[pricelessbrewing]

Probably, but it's going to be rather stressful for a new microbe to grow now. YMMV, I use probiotics for my sours.

 

[BrewDawg79]

If this doesn't turn out I'll try probiotics for the next one. Thanks for all the input.

 

[BrewDawg79]

So after not much pH movement over 4 or 5 days I added 3 shots of good belly probiotics and dropped temp to 95 F (from 105 F). Within 12 hours of making those changes the pH was down to 3.2. Boiled for 20 min, cooled, and pitched two pure pitch packets of wlp029. Just checked gravity after 4 days of fermentation and down to 1.009. Hydro sample tasted great. Exact level of tartness I like for this style. Just thought I'd share my experience. Happy brewing.

 

[ten80]

A pack each of WLP677 and Wyeast 5335. No starter (wish I would have, though). Got lazy.

Wait, kettle sour generally means souring of wort pre-boil in the kettle, so why pitch expensive cultures when the natural Lactobacillus can do the job? Perhaps you boiled after mashing and I missed that part.

I just throw some grain dust in my pre-boil wort to boost the Lactobacillus count in case some were killed during the mash at 150F. Warm temperatures and a lack of CO2 keep the enteric bacteria from fermenting and producing off-flavors.

I take a pH reading by swirling my bucket to offgass some CO2, then dipping a pH strip in the bung hole (airlock removed) and quickly replacing the bung. A pH of 3.2-3.4 tastes right to me and following a 5-min boil, I can still get a pitch of US-04 or US-05 to start, albeit very slowly.

 

[BrewDawg79]

I was following some guidance from a local brewery that started their house culture with those same strains. Might try the raw grain approach next time. Seems like there are quite a few ways to get sour beer.

 

[ten80]

AHH, I think I get it. The brewery is likely boiling the wort prior to pitching the Lacto culture in order to kill the wild micro-organisms present in the wort. Not much sense in pitching Lacto into a melange of organisms unless you have an incredibly strong and active culture to pitch. If boiled prior to pitching Lacto, then the wort doesn't necessarily need to be boiled again before pitching yeast. It would come down to personal preference.

I've done the sour wort method (mash, sparge, collect word, add grains, keep at 110F & free of oxygen) three times now with great success. It creates a good depth of flavor and some intense haze, both of which add to the style.

 

[BrewDawg79]

Correct. They were also boiling after souring to kill lacto in order to keep all "downstream" equipment free from souring bugs. This approach made sense to me as I wasn't sure about dedicating equipment to sour beers just yet. I now have a new appreciation for sour beers, so I will probably go the route you suggested in the future and not conduct the second boil. I also might try adding brett at that point for some extra layers of flavor and aroma.