Trouble with kettle souring

[robcoombs]

Just wondering if anyone has experience with kettle sours? I have a few questions after running into some issues, hoping someone out there can help me out.

[LiverDance]

Ask away!

[jacinthebox]

have made a few successfully...ask away

[robcoombs]

I had a couple of attempts of growing lacto from grain. The first only got the ph to 3.9, the second never moved at all, 4.4. So I started over with L.Plantarum, 4 capsules, 2L starter. Again after 10 days the ph is 3.9. I have family coming to visit so I decide to leave the starter at ~100F for nearly two weeks. After that amount of time I check the ph and it's 3.45, so while I question leaving a starter that long I assume it should be ok. I do my mash as usual, transfer to the kettle. 8gal total as I'm doing a 4 gal dry hop portion and 2.5 gal fruit portion. Pitch the entire starter. After 48 hours I had no noticeable sourness whatsoever. I did have a thin white layer on top at this point. I've kept the temp between 90-115F the entire time. This morning the white layer has moved to the outer edges of the kettle. Still no sourness, I'm going to check the ph this evening but I know it's going to be above 4 by taste.

My question...what gives? I've read Milk the funk, Five Blades, Mad fermentationist and on and on. I can't find anything wrong with what I'm doing but yet I must be. My only issue with not following starter directions was not being able to add lactic acid because I couldn't get any, until alst week when my LHBS finally got some in for me after waiting 4 months.

From everything I've read I keep noticing people writing that you shouldn't leave a kettle sour longer than 5 days, not sure why, I couldn't find an answer to that. Regardless I'm on day three without much, if any, progress. What issues have you guys run into? Is there something in my process that's wrong? I know I didn't exactly lay it all out. I'm thinking about adding the lactic acid now just so I don't have to dump the batch. But I would rather do things "naturally" if possible, especially since I'd like to brew these on a semi regular basis.

Any help would be greatly appreciated!

[LiverDance]

Strange. I'm not familiar with the capsules but for my process I just threw in a kg of grain directly with the full kettle and it sours in about 36 hrs. Since that first time I've just been using some of the leftover wort for "starters". Keep it in my fridge until i do another batch.

[LiverDance]

Also sometimes the original ph of the wort has an effect on it being able to sour. Do you know the ph of the wort going into the kettle?

[robcoombs]

Not exactly, I had run out of calibration fluid for my ph meter. I know through water calculations with my mash it should have been about 4.2. I used 7.5% acid malt in the grain bill to help the lacto have a head start.

[robcoombs]

Everyone I talk to online seems to have no issues souring quickly. :/

[jacinthebox]

I mash as normal (target mash pH of 5.3)...after I mash out I heat it to 180f for 10min. Then reduce the wort pH down to 4.4 with lactic acid, chill, then transfer to a carboy. I add a 1/2 lb of 2row and 1/2lb of acid malt. Then purge with co2 for a min or 2 with my stone wand.
I make sure I fill the carboys up as much as possible (for a 10gal batch I make 12 gal pre boil).
I only cool down my wort 47C. Then put it in my ferm chamber set to 47C.

It normally only takes about 24-27hrs to go from 4.4-4.5 pH down to 3.35pH. then I boil normally.
I will have lots of activity in the carboy...grain floating around...foam coming through the airlock...and that yummy sour smell

[LiverDance]

I also heat to around 190 before i set it down to my 120 target. Not sure if that might have an effect? I also purge the kettle with co2 and cover the top with ceran wrap before I put my lid on. Doesn't seem like you are doing anything wrong. How do you take your samples?

[jacinthebox]

maybe ur meter isn't reading correctly? what temp is your sample

[robcoombs]

Thanks for the replies. I do the same thing @liverdance. I don't have a ferm chamber @jacinthebox unfortunately. Which is why I chose to kettle sour. I keep the kettle on the stove top and turn the element on when needed.

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[robcoombs]

I take my samples through the ball lock of the kettle. I chill to about 20C. I calibrate my meter prior to every test. It's the same one you have.

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[robcoombs]

And again the wort doesn't taste even tart, let alone sour.

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[jacinthebox]

my ferm fridge is only big enuf for 1 carboy. if I brew 12gal of sour I just use my fermwarp/temp controller and wrap it in a few heavy blankets...works like a charm.
I'd be worried about the intense heat from the stove, even if its in short bursts. the bottom of your pot may get really hot

[LiverDance]

That could be doing it. My kettle is electric so I only have small bursts to maintain temp, it never fluctuates more than 3 degrees F. I've done the heat wrap thing as well and it works pretty good.

[robcoombs]

I did worry about that. I don't turn the burner past medium, hoping it won't get extremely hot. But you guys are right.

If that's the issue for the kettle. What could cause the starter to take so long to drop in ph? I wrap my starter in a warming blanket and put it on a heat pad. So the heat for that is constant.

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