Efficiency and pH issues at new brewing location

[Tall_Yotie]

Hey folks. So I helped a work buddy brew beer at his place, third time so far (did a double batch this weekend).

When I brew at my place I get that 75% efficiency target, sometimes better. I don't have a pH meter any more, but when I did I was getting in the expected range.

At his place however, we are hitting 65% efficiency (taking a hit at conversion) and had a 5.00 mash pH. Same equipment and technique. From our water chemistry calculator (using his water profile) we should have been at a 5.40 pH.

Does pH really make that big of a difference? Does it just need a LOT longer rest at a lower pH (more than 60 min)?

Any suggestions on increasing the pH? I know how to lower it, but would adding enough chalk to up the pH cause the flavor to be funky?

Thanks for your time and thoughts!

 

[sicktght311]

Stupid question, but did you mill the grains on the same mill that you usually do, or did you mill on his grain mill. No two mills are alike, and sometimes the gap can be off slightly causing a dip in efficiency

 

[Silver_Is_Money]

Mash pH does not likely appear to be the problem here. I agree with @sicktght311 that it is far more likely to come down to a wider mill gap and thereby a more coarse crush as the cause of the lower efficiency.

In addition, darker brews will tend to have lower efficiencies, and so will higher gravity (SG/OG) brews.

 

[kevin58]

Even if you have identical equipment I bet it's not exactly identical. As mentioned earlier what about milling? What about the water? Are your hoses and tubing the exact same length? Dip tubes? Dead space? Recoverable space? There are a myriad of seemingly small differences that can affect weights and volumes which in turn have an affect on efficiency.

Also keep in mind that efficiency is not a race. 75% does not beat 65%. Yes, you can chase down ways improve it but the main thing is knowing what your efficiency is. Then you can adjust any recipe to your known efficiency to obtain similar results as the other guy.

 

[balrog]

I love the "not a race" comment as that was going to be my point.
I want repeatability. If I do the wheat heavy grist I know to expect different efficiency than Maris Otter heavy grist. But I want to know what it is and not be surprised so that's what I'm always after.

 

[Tall_Yotie]

So. Same mill. No gap adjustment.

For "not a race", that's fair, but it is also a process thing. If getting lower efficiency then there is a hiccup in the system, and for us we want to fix that. If we set recipes for 75% and end up at 65% then we don't hit numbers, and want a recipe I brew at my place to be the same at his place without adding more grain.

Mill may be in need of an adjustment, just ordered a gauge.

But the lower pH than calculated is a concern. I know darker grains will affect it, but that was factored in.

 

[Silver_Is_Money]

So what you are saying is that the identical recipe using identical grist components mashes at 5.4 pH for one efficiency, and at 5.0 pH for another efficiency (all else being equal). The potential for this intrigues me, as can be seen in this thread:

https://www.homebrewtalk.com/forum/threads/what-was-kolbachs-nominal-mash-efficiency.669908/

The question then becomes: How much actual equality is there?

 

[IslandLizard]

Is the efficiency difference in the mash or overall brewhouse? That should point to where to look.
As @kevin58 said, differences in equipment can be the culprit, such as a different mash/lauter system, etc.

Once the mill gap is checked/verified, start going down the chain where things are different. Maybe extra deadspace in the mash tun.

Water composition can definitely play a role too, how accurate is that 5.0 on his pH meter? Is that a cooled down sample at room temps? At what time in the mash?

 

[dwhite60]

... and everything is EXACTLY the same? Same grain, same mill, same thermometer? Everything?

By same grain I mean out of the same bag. All malt is not created equal.

Couple degrees difference on a thermometer could make a difference.

All the Best,
D. White

 

[Tall_Yotie]

Water composition can definitely play a role too, how accurate is that 5.0 on his pH meter? Is that a cooled down sample at room temps? At what time in the mash?

Using a pH meter with ATC, liquid pulled off of the grain, checked 30 minutes into the mash and then right before lautering. Digital pH meter that was verified calibration right before and after use.

For asking about same grain/malt/thermometer, we ordered from the same store (MoreBeer) and I have never had a swing in my efficiency that extreme. A couple degrees in mash shouldn't matter, especially as we were aiming for mid range (150F).

The pH difference is what is more odd. I could get a 0.1 pH difference from water numbers not being the exact same or other factors, but 0.4? That seems like a really huge swing. I was a brewer at a production brewery and we never saw that much swing between a dark and light colored beer, so a light amber ale shouldn't be throwing our numbers off that much.

 

[IslandLizard]

Using a pH meter with ATC, liquid pulled off of the grain, checked 30 minutes into the mash and then right before lautering. Digital pH meter that was verified calibration right before and after use.

ATC only goes so far while hot liquids can damage the probe, unless it was designed for it. Best to calibrate and read samples in a similar temp range.
Hot wort has a lower pH than at room temps, as much as 0.4 pH.

 

[Silver_Is_Money]

ATC can't compensate for the fact that acidic liquids are more acidic at higher temperatures. All ATC can do is assure you that (for example) 5.2 pH at 150 degrees is a correct reading, and so is 5.5 pH for the same sample at 70 degrees. Without ATC you need to do a bit of math to discover that what you are measuring is factually 5.2 pH at 150 degrees and 5.5 pH at 70 degrees.

What ATC does not do is attempt to outright lie and tell you that the 5.2 pH at 150 degrees sample is actually 5.5 pH (because it is actually 5.2 pH).

I wish that those selling pH meters would come clean on this.

 

[balrog]

The way I think about it is that ATC merely adjusts calibration when you are not calibrating at exactly 25C. And as SiM says, ATC will do absolutely NOTHING for you if you are measuring mash sample at 150F and want to know what it "would be" at 77F.

 

[kevin58]

This is just me but instead of chasing my tail trying to get two systems to match each other I would just accept that they are different and adapt. As long as you consistently get 75% and he consistently gets 65% it isn't that difficult to simply adjust the recipe to whichever system you are brewing on. Do this and you will "hit your numbers."

Also, Hhaving a different efficiency between the two brew houses is not a hiccup in the system. Because there are bound to be differences between his system and yours so it should be expected.

 

[Tall_Yotie]

Samples were indeed hot, so next time will let them cool and re-measure.

 

[CascadesBrewer]

Samples were indeed hot, so next time will let them cool and re-measure.

So it sounds like your measured pH (at mash temps) were pretty much on target with the prediction after accounting for correction and in a decent range for the mash.

It is not clear to me, are you actually physically taking your equipment over to your buddies place or does he just have a setup that is the same or similar to yours. Are you using your mill for both locations or do you both just have the same brand of mill? How are you measuring volumes?

 

[Tall_Yotie]

....It is not clear to me, are you actually physically taking your equipment over to your buddies place or does he just have a setup that is the same or similar to yours. Are you using your mill for both locations or do you both just have the same brand of mill? How are you measuring volumes?

It is a blend of equipment. But the big thing was low initial conversion of the mashed grains. But apparently my mill was slightly too wide and the crush was bad. It looked ok, but after adjusting (now that I have guages) I see that I was way off. I may just have a way better setup at home and so I was working through a poor crush, but for him I was not.

So the pH mystery seems to be that I was overconfident on the range of the ATC for the meter, and that we just had a poor crush most likely. Oops!

 

[Silver_Is_Money]

So the pH mystery seems to be that I was overconfident on the range of the ATC for the meter, and that we just had a poor crush most likely. Oops!

There is no such thing as a range of correction for an ATC pH meter such that it will alter pH readings so they can be read at any temperature within the range of ATC and come out identical thereby.

 

[balrog]

Right. ATC is not STC.

https://www.westlab.com/blog/2017/11/15/how-does-temperature-affect-ph