[klickitat jim]

The figure for adjustment with 88% lactic is ~.1 5 ml per pound grain bill.

Interesting - the amount used to adjust is based off the size of the grain bill only? I'd love to have the formula dialed in to avoid having to goose it little by little.

I'm feeling good about mashing at 5.4-5.5, dropping the kettle pH to 5.3, then potentially minor tweaks in the final. Only variable left is understanding more the desired final pH in different styles. May have to start taking more readings and work on a spreadsheet.

I had that mental struggle too. What? No volume concern? But I think that its looking at buffering capacity vs acid added. The compounds from the grain buffer, water not so much. So obviously its talking about pounds per grain in whatever the total volume is. In other words, if you had 10lbs in 5 gallons, its calling for 1.5 ml Lactic to drop .1 pH. So if you were only going to acidify half of the volume, you'd use half of the required acid. Total volume would only play into it on a much larger scale or really high RA water, where the water would then start to buffer the acid too.

Something to keep in mind is that this is not like a topographical grid map with a GPS. Its more like a hand drawn map that is somewhat to scale with a magnetic compass. What I would maybe try is, say you have 5 gallons of APA in a keg, the grain bill was 12 lbs in a 6 gallon batch... and the pH is currently 5.4 and it tastes a little dull and you'd like to try it at 5.3 pH. 12 x .15ml is 1.8ml lactic for 6 gallons. 5/6 = .83 × 1.8 = 1.5ml and if you want to try it in a pint thats 1/40th of that.. or ~.04 ml in the pint. When its right, dose the keg. Keep in mind that its only 4.75 gallons now. (I used lactic in this math example, but phosphoric is what I prefer for dosing nonsour beers. That would be 12 x 1.75 = 21 ml 10% phosphoric for 6 gallons. 21x.83 = 17.4 ml for 5 gallons. Or .87ml for a pint. Much easier to measure that amount and 10% phosphoric may have less chance of a negative flavor impact that 88% lactic.

Honestly I think thats getting more nitpicky than we can detect by taste... I've been having good luck moving it .1 at a time then retasting once its homogeneous.

But post your findings please.

Also, this might make an interesting triangle test for Denny and Drew at some point

[klickitat jim]

One other thing regarding the accuracy issue while im thinking of it. My pH meter only goes to tenths. So my pH reading of 5.3 is actually 5.3(?) because I have no idea how many hundredths. So it might be 5.39 and then I adjust and it reads 5.2 but its actually 5.21 pH.  Thats a drop of 1.7 not 1. On the other hand, I might get an initial reading of 5.3, add the acid and its still 5.3 and I say "what? No change?" But maybe the initial was actually 5.39 and now its 5.31.  And remember that Kai's chart shows a sliding scale. My numbers are just the middle point of that scale.

The amounts per pound grain bill are just fairways and greens, not guaranteed holes in one. The meter is just there to double check. Go by taste.

[klickitat jim]

For convenience, here are screen shots of Kai's charts

[Wort-H.O.G.]

Jim- don't know this for fact, but I would think the ph meters have rounding logic. If 5.45 or lower then it reads 5.4. If 5.46 or higher reads 5.5.

If this is true, most you would be off would .05.


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[ynotbrusum]

Jim, another variable that I encounter is when grains are added to the mash (i.e., timing) - I frequently add dark grains at the end of the mash for say, color adjustment without roast flavors.  I can see kettle or final beer pH adjustment applying to that situation (I have always just run it through Brunwater with the original mash grains and ignored the late dark grain additions as to pH calculations).  Now you have me thinking.....

[klickitat jim]

Jim- don't know this for fact, but I would think the ph meters have rounding logic. If 5.45 or lower then it reads 5.4. If 5.46 or higher reads 5.5.

If this is true, most you would be off would .05.


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That could be, but either way tenths is close enough for me.

[klickitat jim]

Jim, another variable that I encounter is when grains are added to the mash (i.e., timing) - I frequently add dark grains at the end of the mash for say, color adjustment without roast flavors.  I can see kettle or final beer pH adjustment applying to that situation (I have always just run it through Brunwater with the original mash grains and ignored the late dark grain additions as to pH calculations).  Now you have me thinking.....

Ya you might want to check and see what that's actually doing. Unless you are dumping a crap ton in though, it shouldn't make a huge difference

[hopfenundmalz]

Nice find Jim. How did I never see that with all of my poking around Kai's site?

[Joe Sr.]

Jim- don't know this for fact, but I would think the ph meters have rounding logic. If 5.45 or lower then it reads 5.4. If 5.46 or higher reads 5.5.

If this is true, most you would be off would .05.


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You could be off by .09 when you're taking two readings to compare the impact of the additions if the first reading rounds down from .04 and the second one up from .05. Both could read 5.3.


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[klickitat jim]

Well to solve our speculation I looked it up. My Milwaukee MW100 not only displays to only the tenth but is only acurate to +/-.2 pH. Does this freak me out? Not a bit. As long as I test samples with the same meter, in the same state (68-70F and still) its good enough for me. Much more accurate than my eyeball with colorphast. Someday when I'm adrift in excess money I will upgrade to an MW102.

Besides, for final ph I think taste is the first test, the meter is just for knowledge sake.

[AmandaK]

Nice find Jim. How did I never see that with all of my poking around Kai's site?

Agreed, good find Jim. Can't believe I've never found that on Kai's site either. This thread is much more informative than the "wouldn't you like to know" answer I received previously.

I've been playing with this subject at home, but I haven't taken very good notes - just more of a 'does this make a difference?' kind of thing. I'll be reporting some findings in the near future.

[stpug]

... if you want to try it in a pint thats 1/40th of that.. or ~.04 ml in the pint. With a oral medicine syringe ($2 at pharmacy) you can do that. ...

The pint equivalent was wrong above - 0.04ml for lactic. And you'd probably need to work that out with a dropper since most oral medicine syringes can't get you to that level of detail.

Edit: Turns out that one drop is ~0.05 mL, so one drop should do it per 16oz.

[klickitat jim]

... if you want to try it in a pint thats 1/40th of that.. or ~.04 ml in the pint. With a oral medicine syringe ($2 at pharmacy) you can do that. ...

The pint equivalent was wrong above - 0.04ml for lactic. And you'd probably need to work that out with a dropper since most oral medicine syringes can't get you to that level of detail.

Edit: Turns out that one drop is ~0.05 mL, so one drop should do it per 16oz.

Yup, typo on the decimal point. I fixed it.

[stpug]

... if you want to try it in a pint thats 1/40th of that.. or ~.04 ml in the pint. With a oral medicine syringe ($2 at pharmacy) you can do that. ...

The pint equivalent was wrong above - 0.04ml for lactic. And you'd probably need to work that out with a dropper since most oral medicine syringes can't get you to that level of detail.

Edit: Turns out that one drop is ~0.05 mL, so one drop should do it per 16oz.

Another reason to use 10% phosphoric for final adjustments.

Good point! Unfortunately, none of my LHBS carry phosphoric - only lactic. But I will certainly be adding some to my next online order from wherever.

On a side note, I cannot say I've ever reached a level of lactic acid additions where the flavor was noticeable with the exception of a failed batch of gose that was doused with it to see how it would work out (turned into about 4 gallons of garden water ).

[klickitat jim]

... if you want to try it in a pint thats 1/40th of that.. or ~.04 ml in the pint. With a oral medicine syringe ($2 at pharmacy) you can do that. ...

The pint equivalent was wrong above - 0.04ml for lactic. And you'd probably need to work that out with a dropper since most oral medicine syringes can't get you to that level of detail.

Edit: Turns out that one drop is ~0.05 mL, so one drop should do it per 16oz.

Another reason to use 10% phosphoric for final adjustments.

Good point! Unfortunately, none of my LHBS carry phosphoric - only lactic. But I will certainly be adding some to my next online order from wherever.

On a side note, I cannot say I've ever reached a level of lactic acid additions where the flavor was noticeable with the exception of a failed batch of gose that was doused with it to see how it would work out (turned into about 4 gallons of garden water ).

Agreed. There's a bunch of sour heads who say 3.5ph beer they can't detect the sourness lol. I choose which acid to use depending on amount needed and beer style. A touch of sulfur may play better in a lager, lactic might play better in fruity ales. But you are right, unless you drop it below 4.0 ph most likely you won't taste lactic