Considering tackling my first sour- have question about Lactic Acid

[boomtown25]

I am planning on attempting a kettle sour in the near future using Omega Labs Pantarum blend yeast. All the info I have read said a good idea is to add lactic acid to your kettle to drop your PH down to around 4-4.5 before your lacto yeast is pitched. Everywhere I look, I only see powder form Lactic Acid. Is this acceptable and if so, how much is the proper amount to add? If not, where do I find the liquid Lactic acid I see people adding to their wort in youtube videos?

**Correction- I re-looked and the bottle says "fluid ounces" so I guess it is liquid, it was just in a container that appeared to normally hold powdered items like yeast nutrient. Still, correct stuff and how much??

 

[cactusgarrett]

I've never seen (or heard) of it as powder. I would imagine you'd have an easier time sourcing the liquid version, especially at a homebrew shop. For example:

How much you need is dependent on your water, grainbill, etc., so a WAG from someone here might not suit you. For example, my kettle sours have needed 10mL due to my higher residual alkalinity of my tap water. Ideally, you'd be using a pH meter and actually measuring your wort as you add the lactic acid.

 

[shanecb]

It depends on your specific water chemistry and such, but a good starting point is 1mL of 88% lactic acid for every 0.1 you need to lower the pH of 5 gallons. So if you were lowering 5 gallons of wort from 5.5 to 4.5 you'd want to use 10mL. YMMV, though

 

[newtobrew1981]

Have you thought about adding in some acidulated malt late in the mash.

 

[newtobrew1981]

Fwiw I just soured in my carboys without lowering my ph and it came out fine

 

[Rob2010SS]

I usually use about 2 teaspoons in my kettle sours to get them down to the 4.4 mark, which, is approx. 9.85 mL. So, right along the lines of what everyone else has said.

As @cactusgarrett stated though, you should get a pH meter and check the pH with that. You'll be much better off that way. You can get a cheap one for $15 or $20

 

[cactusgarrett]

I just soured in my carboys without lowering my ph and it came out fine

I'm confused by this; what do you mean? How did you sour something without lowering pH?

 

[newtobrew1981]

What I mean is I put the wort into the carboys then pitched the lactic bacteria I did not lower the ph before pitching the bacteria

 

[cactusgarrett]

AH! Brain-fart; i get it - i was taking it out of context. My bad.

 

[boomtown25]

Thanks everyone. I do already have the ph meter, just haven't used it yet. I am a huge "think of everything that can go wrong before you shoot yourself in the foot" type person so I probably jumped the gun on the question concerning the powder/liquid. I was looking at actual liquid I could buy, so that part was moot, but the amounts to use help greatly. Thanks!