Ph meter

I'm thinking of purchasing this Ph meter for mash testing. It auto-compensates for temperature.

I'd like to keep it under $100.

Any input or alternatives would be appreciated.

EDIT: Never mind. Temp only goes to 140 F.

What do others use?

I looked around a bit before I bought my meter. I didn;t see many that would go the full gamut of mash temps without costing some bling.

I settled on a Hannah Checker 1 for $50 plus the cost of calibration fluids and storage solution.

GilaMinumBeer said:

I looked around a bit before I bought my meter. I didn;t see many that would go the full gamut of mash temps without costing some bling.

I settled on a Hannah Checker 1 for $50 plus the cost of calibration fluids and storage solution.

Click to expand...

The price is right, that's for sure. ~$30 on ebay. Do you compensate for temp or isn't it a big deal?

My old meter stopped reading accurately and it's as much to replace the sensor as it would be to purchase new.

After reading Kaisers review, I am looking at getting this one:

http://www.eseasongear.com/milwaukeesm102.html

He suggested the 101 model but it isn't too much more for the 102.

Never compensated for temp. Have always just took the measure at testing temp.

Hanna Checker gets some bad rap tho' as a cheap "junk" meter. Mine has always, so far, calibrated and held the calibration well.

IIRC, the only issue with using above rated temp range is lifespan of the probe head. But, I found new heads for only like $10 online.

humann_brewing said:

After reading Kaisers review, I am looking at getting this one:

http://www.eseasongear.com/milwaukeesm102.html

He suggested the 101 model but it isn't too much more for the 102.

Click to expand...

I saw that too. After I bought mine. 70c is what 160*F?

nine fifths, carry the one,................Bah. Damned Metric.

I just bought the one Kaiser recomended (came yesterday!). It does not have automatic temperature compensation. It has to be set manually. I believe Kai posted it somewhere, but putting the pH probe in hot wort (or any hot liquid) will shorten the lifespan of the probe. I plan to pull a small sample, let it cool, and then check pH.

Milwaukee SM-101

From the same place I also ordered an aquarium heater. My house is on the cool side so brewing ales in winter is actually a bit problematic. Now I can set up a nice waterbath for my carboys.

From BrauKaiser;

"
The pH of a solution changes with its temperature. This needs to be taken into account when measuring the pH and determining what the pH target is. Some authors cite the pH ranges and targets at the actual reaction temperature (i.e. rest temperature) and others cite the pH values as if measured in a cooled sample. The latter makes sense since it is a good practice to cool a sample before measuring it with a pH meter. It also gives a common reference and allows for giving pH values without the need of giving a temperature as well. Unless otherwise noted, all pH values on this wiki are pH values measured at room temperature (25 C). To make matters even worse, the temperature dependency of the pH is also dependent on the substrate itself. Briggs quotes a difference of 0.35 in pH between a mash pH measured at mash temps and the same liquid measured at room temp. The pH measured at mash temp is lower [Briggs, 2004]. "

which is why I've just always tested at temp. To be sure.

Replacement HI1270 probe on ebay for $20.

I think I'm going to pull the trigger on this one.

http://www.eseasongear.com/milwaukeesm102.html

I like the ability to read without adjustment at mash temps, even if that process will shorten the life of the probe.

Thanks all for your input and help

Cheers!

BTW - I plan to lower mash/sparge Ph with 10% H3PO4

Hugh_Jass said:

BTW - I plan to lower mash/sparge Ph with 10% H3PO4

Click to expand...

It gets interesting with steps.

Hugh_Jass said:

http://www.eseasongear.com/milwaukeesm102.html

I like the ability to read without adjustment at mash temps, even if that process will shorten the life of the probe.

Click to expand...

According to the specs, the ATC range is 0 - 50C (122F). Unless you're doing large steps, that falls out of the normal mash temp range.

lamarguy said:

According to the specs, the ATC range is 0 - 50C (122F). Unless you're doing large steps, that falls out of the normal mash temp range.

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Isn't it automatic temp compensation 0-70C with the 102 model?

http://lib.store.yahoo.net/lib/yhst-83212413117752/Mil-Guide-SM100-101-102-500.pdf

The SM102 looks like it reads 70 C to me

Edit: It appears the automatic compensation only goes up to 50 C.

http://www.milwaukeetesters.com/SM102.html

Hugh_Jass said:

Isn't it automatic temp compensation 0-70C with the 102 model?

http://lib.store.yahoo.net/lib/yhst-83212413117752/Mil-Guide-SM100-101-102-500.pdf

Click to expand...

Link didn't work for me but, according to easong spec pH range is 0-70 but ATC is only 0-50

A good read on temp correction

lamarguy said:

According to the specs, the ATC range is 0 - 50C (122F). Unless you're doing large steps, that falls out of the normal mash temp range.

Click to expand...

looks like they took info from the 101 model, the 102 does compensate to 70C

http://lib.store.yahoo.net/lib/yhst-83212413117752/Mil-Guide-SM100-101-102-500.pdf

Edit, looks like I am too slow

humann_brewing said:

looks like they took info from the 101 model, the 102 does compensate to 70C

http://lib.store.yahoo.net/lib/yhst-83212413117752/Mil-Guide-SM100-101-102-500.pdf

Edit, looks like I am too slow

Click to expand...

I keep getting redirected to http://smallbusiness.yahoo.com/ecom...s_acq_links_20090901?AID=10432562&PID=3428929 from that link.

GilaMinumBeer said:

Link didn't work for me but, according to easong spec pH range is 0-70 but ATC is only 0-50

A good read on temp correction

Click to expand...

Thanks for the link.

"

When temperature changes, the actual pH of the solution being measured changes. This change is not an error caused by the change in temperature. It is the true pH of the solution at the new temperature. Since this is not an error, there is no need to correct or compensate for this temperature effect. To be absolutely correct, document both the pH and temperature of the sample. "

Click to expand...

So the important Ph reading is the measurement at mash temp?


Also, just got off the horn with a rep. at Milwaukee Instruments. He recommended the SM 102. It will auto correct up to 70 C, but at that temp the probe's expected life span will be shortened as indicated by the environment 0 to 50°C; max RH 95%

Hugh_Jass said:

So the important pH reading is the measurement at mash temp?

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A temperature increase causes the solution pH to fall. At mash temperature (150F - 160F), the pH will be 0.2F - 0.3F lower than at room temperature (78F).

For example, I take a mash sample at 152F and let it cool to 78F. At room temperature, the pH reads 5.5 so the actual mash pH is ~5.3.

You should target a pH of 5.4 - 5.6 at room temperature, depending on the beer style.

Hugh_Jass said:

So the most accurate reading is the measurement at actual temp?

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Fixed a bit as I understand it.

For example;

if you are adjusting sparge water you should first heat the water to sparge temp before testing and adjusting.

if you are adjusting for a specific enzymes optimal pH range, heat the mash to that rest and then test pH. For this I use Palmers chart.

lamarguy said:

...than at room temperature (78F).

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If you live in the freekin' amazon.

Sorry, couldn't resist.

Bottom line - if you care about the life of your electrode, you should really test the mash pH at room temperature.

I think everyone can handle subtracting 0.2 from the reading. If not, well...

lamarguy said:

Bottom line - if you care about the life of your electrode, you should really test the mash pH at room temperature.

I think everyone can handle subtracting 0.2 from the reading. If not, well...

Click to expand...

I respect that and I am not argueing but, seriously, whats the real correlation to life span? Is it halved, quartered, what? Are we talking months of lifespan as opposed to a year or two?

And, dumb question, is there a chart or calculator for temp correction (like with a hydrometer)?

these are the things I have wondered but, haven't cared to look for considering the price point of the meter I bought. If I plunked down for the 102 I'd be more concerned. PS, this is good to note too. Not a bad price really considering the initial investment.

lamarguy said:

Bottom line - if you care about the life of your electrode, you should really test the mash pH at room temperature.

I think everyone can handle subtracting 0.2 from the reading. If not, well...

Click to expand...

Well, I can keep my abacus handy on brew days

Thanks all for your help

GilaMinumBeer said:

I respect that and I am not arguing but, seriously, whats the real correlation to life span? Is it halved, quartered, what? Are we talking months of lifespan as opposed to a year or two?

Click to expand...

I imagine the effects are probe specific, so there's no real estimation that I'm aware of. At a minimum, you will absolutely need to calibrate your meter are each dunk in hot wort as the response will drift faster due to accelerated electrode wear.

From Kaiser's How pH Affects Brewing:

To make comparing of pH measurements easier it is best to take them at a standard temperature; 25 C/77 F or 20 C/68 F are common. Some brewers use their pH meter to test the pH directly in the mash. But testing hot liquids reduces the lifetime of the probe which is why I don't recommend this practice.

Most homebrewers measure the pH of a cooled mash sample when checking pH. While pH meters are able to measure the hot mash pH it is not advisable to do so because it shortens the life of the probe.

Click to expand...

GilaMinumBeer said:

And, dumb question, is there a chart or calculator for temp correction (like with a hydrometer)?

Click to expand...

There's not a chart, per say, but there have been experiments to estimate the pH shift. DeClerk cites a 0.35 pH shift while others have found the shift to be in the 0.2 range. So, I go with shift range of 0.2 - 0.3, discounting the inherent meter inaccuracy.

From Kaiser's Overview of pH:

For wort it has been reported that the pH at mash temperatures (65 C/150 F) is about 0.35 pH units lower than at room temperature and at mash out temperatures (75 C/170 F) it is even 0.45 pH units lower [Briggs, 2004]. While my own experiments showed only a ~0.2 pH difference between a sample at mash temperature and a sample at room temperature (25 C/77 F).

Click to expand...

Also, a note about ATC from Kaiser's pH Meter Buying Guide:

NOTE: many brewers think that ATC means that you can test the mash pH at any temp within the pH meter’s temperature range. While this is true you still need to know the temperature dependent pH shift in order to correct the pH temp to the standard temperature at which the optimal pH targets were published. Briggs and DeClerck cite a pH shift of -0.35 between a room temps and a mash temp sample while my own experiments showed only -0.18. There doesn’t seem to be much data about this shift out there and the majority of the pH values that are given for brewing are room temp pH measurements. Just because a meter has ATC it is not more accurate, especially if the sample's temperature to pH function is unknown.

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Thanks for that. At first purchase I had been testing the calibration after each dunk just to see how well the meter held.

My curiousity on the chart was given that I tend to do some step mashes. Mostly just a protein rest in addition to my sacc rest.

So, by this, I suppose the best approach is to test at rest temp and then a cooled sample and note the difference for future reference or, throw caution to the wind and see how long I can go til the probe goes and justify purchase of the 102.

Ha, either way - God speed!

When a scientist determines the pH optima for any enzyme, they will do it at a Standard Temperature and Pressure (unless measuring temp. of pressure optimas). STP is 20*C and 1 Atmosphere.

The optimal pH values shown here for the important malt enzymes are those at STP. That's where I'd prefer to measure my pH

Palmer HTB Ch. 14

If you want to measure the pH of hot wort, then when you calibrate the meter, you should also do this at hot wort temperatures. Any piece of equipment should be calibrated at the temperature it will be used at to ensure the greatest accuracy