Playing around with final beer pH

[klickitat_jim]

@mchrispen

That Weyerman pH thing - I hope that list of beer style was referring to finished beer pH and not actually mash pH (even at mash temps).

Jim, I agree that with many beers adjusting the finished product with acid can help. The inverse is true, using a little bicarbonate in darker beers can seem to make them richer and maltier. That said - I approach this more like seasoning a dish than a hard and fast rule.

By the way - Kudos to this guy right here! Matt gave me my ph meter and got me heading in this direction.

My course so far has been like this…
Thanks Palmer, for teaching me to make beer from a kit
Thanks Denny, for simplifying all grain
Thanks Drew, for helping my not have kitchen sink grain bills any more
Thanks Martin, for helping me understand, er… vaguely understand water just enough to get by
Thanks Jamil and Mark, for helping me wrangle my miniature brewers
Thanks Erik and Matt, for helping me measure and fine tune ph

As well as countless others with various issues along the way…

Ive made a few recent tweaks to things that are about to all come together. My hope is to go from consistently making 35-40pt beers to consistently making 40-45pt beers. I think sometimes that difference is a small thing, like .1 ph difference in the glass.

[wort-h.o.g]

the end of the deck is shameless pitch for their acidulated malt

I love that stuff.

Admittedly I have not mastered its usage- likely why have most of a 10# bag of acidic ayes mat and less in my lactic acid bottle.

[system]

@erockrph

@mabrungard

There are some German breweries that mash at a more typical 5.4 to 5.5 pH and then drop the kettle wort pH a couple of tenths.

Two words “limit dextrinase”

Depends on their mash temps. Limit dextrinase activity drops off above 145F. And while it’s peak activity is at 5.4 pH, it still is pretty active in the range from 5.0-5.8.

Actually IIRC Limit likes 5.1 the best.

[system]

@erockrph

Depends on their mash temps. Limit dextrinase activity drops off above 145F. And while it’s peak activity is at 5.4 pH, it still is pretty active in the range from 5.0-5.8.

I believe that we have covered this paper in the past, but I am reposting it for those who were not part of the discussion: http://onlinelibrary.wiley.com/doi/10.1002/j.2050-0416.1999.tb00020.x/pdf

[erockrph]

@erockrph

Depends on their mash temps. Limit dextrinase activity drops off above 145F. And while it’s peak activity is at 5.4 pH, it still is pretty active in the range from 5.0-5.8.

I believe that we have covered this paper in the past, but I am reposting it for those who were not part of the discussion: http://onlinelibrary.wiley.com/doi/10.1002/j.2050-0416.1999.tb00020.x/pdf

And the TL;DR quote from the summary:

[quote]The temperature optimum of the limit dextrinase of a malt extract was 60-62.5°C And the pH optimum 5.0-5.5. In The pH range 5.4-5.8, The limit dextrinase activity was the higher, the lower the mash pH.
[/quote]

[system]

A pH of 5.4 to 5.5 is the balancing point for limit dextrinase with respect to alpha amylase and beta amylase.

“In a second set of high gravity mashings with the same Kymppi malt the mashes were taken through the mashing programme of the high gravity mashing procedure and the apparent fermentabilities of the worts were determined (Fig. 5). Lowering the mash pH from 5.7 to 5.4 increased the apparent fermentability, but as the pH decreased below 5.4 a decrease in the fermentability value was observed. Lowering the pH from 5.7 increased the limit dextrinase activity (Fig. 4), but did not affect the alpha-amylase activity and slightly decreased the beta-amylase activity (results not shown). When the mash pH dropped below 5.4 the increase in limit dextrinase activity was counteracted by a marked decrease in both alpha-amylase and beta-amylase activities resulting in lower apparent fermentabilities. When comparing the mashing results with those in Figure 3, it should be borne in mind that at mashing temperatures the pH is lower than that of cooled wort.”

[klickitat_jim]

I stumbled onto interesting info while studying Kai’s pH intel. He states in his chart that 1.47-1.96 ml of 10% phosphoric acid per pound of malt will drop a mash by .1 pH.  I ballpark averaged that to 1.75ml, the beer had a 12 lb grain bill. Guess what that came out to? 21ml of 10% phosphoric to drop the pH .1. If you read back I used 5ml first, then 20 more and reached -.1 pH.

So it appears that in the final beer Kai’s calculations may still apply. If you try it, report back. It would be interesting to compile some findings.

To lower pH in final beer by .1 pH try 1.75ml of 10% phosphoric per pound of grain bill
To raise pH in final beer by .1 pH try .3 g of baking soda per pound of grain bill (keep in mind the saltiness at too high of a level)

[jonhughey_att.net (HoosierBrew)]

@klickitat_jim

I stumbled onto interesting info while studying Kai’s pH intel. He states in his chart that 1.47-1.96 ml of 10% phosphoric acid per pound of malt will drop a mash by .1 pH.  I ballpark averaged that to 1.75ml, the beer had a 12 lb grain bill. Guess what that came out to? 21ml of 10% phosphoric to drop the pH .1. If you read back I used 5ml first, then 20 more and reached -.1 pH.

So it appears that in the final beer Kai’s calculations may still apply. If you try it, report back. It would be interesting to compile some findings.

To lower pH in final beer by .1 pH try 1.75ml of 10% phosphoric per pound of grain bill
To raise pH in final beer by .1 pH try .3 g of baking soda per pound of grain bill (keep in mind the saltiness at too high of a level)

Good info.

[klickitat_jim]

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

[BrodyR]

@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.

[klickitat_jim]

@BrodyR

@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.

[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.

Sent from my iPad using Tapatalk

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

[klickitat_jim]

@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…

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?

[jrdunne (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.

Sent from my iPad using Tapatalk

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.

[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.