Adjusting ph post boil for Controlled Primary Souring

Ingredients
1

I’ve got this idea that dropping my ph post boil to 4.5 before pitching lacto in primary, would be a decent way of reducing the risk of contamination during souring week. I couldn’t find any suggestions on how much 88% lactic would do the job. My mash and sparge were 5.2 ph, and post boil was 8 gallons of 5.0 ph with a 100% Pilsner no hops, blonde sour. I chilled to 100° whirlpooling, and pulled a sample. Cooled to 70° and it was 5.0 ph. I then took a wild guess and added 15ml of 88% lactic.  That brought it down to 4.5 ph on the button.

Just FYI

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Thank you for posting this.  I was just thinking about this very same thing while planning my next sour ale.  Also, good ballpark estimate!

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I know, right? I started thinking my meter was stuck at 5.2 but post boil was 5, then 4.5 after the lactic. Then I recalibrated just to be sure and still dead on.

I’m hopeful that this meter will be the next leap in my beer quality. It will be nice to remove the ph guess work.

4

Just another instrument to measure important parameters. You know that you can brew without a thermometer or a hydrometer? A guy in the club does for his historic brews on a historic system.

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I do a big sour starter ~1/3-1/2 gallon per 5 gallon.  The wort drops below 4.5 with the pitch.

6

Take a read of Derek Springer’s presentation from NHC. He speaks specifically to this. However, with a pH meter, should be easy enough.

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I’ve just made a ballpark guess by using the water calculator in Brewer’s Friend. But I did mine preboil. I’m not sure if there’s any other relevant chemistry going on in the boil other than simple concentration of the wort.

And it shouldn’t make much of a difference if you overshoot a bit and end up lower than 4.5 by a few decimal points. Remember, it takes 10 times as much acidity to go from 4.2 down to 3.2 than it does to go from 5.2 to 4.2.

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Update:

This round of sours are going really nicely. The 28Bs have been in the closet for a month and I just slid the 28Cs in there after purging and topping off with fruit. The 28Cs were adjusted to 4.5 post boil, then primaried for a week on wy5335 at 100º then dropped to 70º and wy5526 was pitched. After a total of a month, they are 1.010 and 3.2 pH. No off flavors and quite clean the way I like them. They 28Bs each got an oak spiral, and the 28Cs got a spiral and ~16 lbs each of peach or cherry puree from Oregon Fruit. That is really nice fruit for brewing by the way. It is a thick juice with no skins no seeds. Sinks rather than floats like whole fruit. I think I will be pleased.

Now to babysit blowoff tubes for a couple weeks [emoji1]

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I know of a “guy” who would be glad to help baby sit for beer…Just saying.

10

How cool would that be? Honestly, im not expecting much blowoff. Brett doesnt go crazy to begin with, and this will be 6 gallons of about 3-4 plato mixed with about 2 gallons of 12 plato, so avg around 5-6 plato. It shouldnt rocket. Main concern is head space. There isnt much.