How I Calibrate My pH Meter to Take a Mash Reading

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Just wanted to throw up a quick tutorial on how I calibrate the pH meter I use for checking my homebrew mash pH.  I calibrate it before every reading.  I know it is probably a little over-kill calibrating it that many times, but the meter was pretty cheap on Amazon and calibrating it is easy.  The accuracy is +/- .1 so if I am able to get it to 5.3 or 5.4, I am happy.

I begin my removing my sample after the mash has been mixed well (Glass 4)and set for a few minutes.  From right to left, I have some distilled water in Glass 1 and a small bottle with distilled water to help rinse the probe.  I change out the distilled water in Glass 1 if it gets cloudy.  Glass 2 has the 7.0 buffer solution and Glass 3 has the 4.0 buffer solution.  Glass 4 has my mash sample and it is time to get started.

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I begin by rinsing the pH meter in the distilled water (Glass 1) for a minute.  I then place it in the 7.0 buffer solution (Glass 2).  Make sure your meter is turned on.

Rinsing:

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Reading:

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The reading is .1 off so I use the screw adjustment on the back of the pH meter to adjust.  You will have to see which way adjusts your meter up or down, but it only takes a very small amount of adjusting to get it where you want it.

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After slight adjustment:

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Once that is set, I rinse the probe in the distilled water (Glass 1) and then use my little bottle squirter to rinse it again before the next reading.

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Once the meter is rinsed with the squirter, I shake off the excess water and place it into Glass 2, the 4.0 buffer solution:

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The 4.0 check was good to go.  Now time to check the mash sample.  The sample was still warm so I cooled it to room temperature.  The instructions did not say what temp exactly (room temperature) so I just made sure all glasses were about the same.

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After it is cooled I checked it with the pH meter and BAM!

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5.4 is within range so I was stoked.  I had some lactic acid on standby just in case I needed to lower the pH.  To lower the pH if needed, I would stir in 1 ml or 1/4 tsp at a time to your mash and check the pH again until you reach your target pH.  If I had to raise the pH, I have baking soda or chalk (calcium carbonate) on standby and would add the same amount until it was where I wanted it..

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That is it.  It goes pretty quick after you do it once or twice.  I would recommend you practice calibrating the pH meter a couple times to get used to the process.  If you have to adjust your pH, you want to do it as soon as you can.

I will be using this meter until I can pick up this one by Hach.  That is the same brand we use in the water lab at work.  HERE is another option for $20 and Prime that is better than the one I have.  Cheers!

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