Miscellaneous Parts

 

pH meter

Proper mash and water pH adjustment requires us to measure pH.

We use a Hanna Phep 5 pH meter (model HI 98128) to take these measurements. It is completely waterproof and even floats. (Yes, we have dropped ours at least once in our boil kettle!)

Just like the digital probe thermometer, having a waterproof pH meter is (in our opinion) an absolute must. We don't have to worry about humidity from kettles getting into the unit and cleaning it under the faucet is dead simple and worry-free as there is no chance of getting the wrong parts wet.

The Phep 5 model also includes 2-point calibration for greater accuracy, a built in thermometer (very handy), and automatic temperature compensation up to 140F. The electrode (tip) is replaceable too. When brewing approximately once or twice a month we've been able to get 5-7 years out of an electrode. Once the readings start to jump around, it's time to replace the electrode.

You can purchase cheaper pH meters but they're not waterproof, do not float, only include 1-point calibration (not as accurate), are not temperature compensated, and do not have replaceable electrodes. Once again, you get what you pay for.

Be careful when purchasing your Hanna Phep 5 pH meter (model HI 98128). There is also a slightly less expensive Hanna Phep 4 pH meter (model HI 98127) that looks identical but only has +/- 0.1 pH accuracy. Make sure to check the model number. 

Hanna Phep 5 pH meter (model HI 98128) and replaceable tip:

Measuring the sweet wort pH in the Boil Kettle before boiling (5.35 pH, 137.2F):

Using and maintaining our Hanna Phep 5 pH meter also requires a few extra items:

  • 4.00 pH calibration solution: Used for doing the lower end of the 2-point calibration of the pH meter. The instructions have you set the meter to calibration mode and you place the end into one solution at a time when prompted.
  • 7.00 pH calibration solution: Used for doing the higher end of the 2-point calibration of the pH meter.
  • pH meter storage solution: When we're not using the pH meter, we put this storage solution in the tip to keep the electrode from deteriorating. Water (even distilled water) should not be used for storage.
  • Distilled or reverse osmosis (RO) water: Used to wash off the pH meter electrode before putting the meter into the storage solution until the next brew day.
  • Laboratory wash bottle: We use a plastic squeeze wash bottle to dispense the distilled or RO water when cleaning off the pH meter. The ones with the curved neck used in laboratories work well.  

From left to right: 4.00 pH solution, 7.00 pH solutionStorage solution, Wash bottle.

How often you calibrate your pH meter is completely up to you. The instructions say to do it once a month, or every time you use it if high accuracy is required.  We do it about every 6 months which is about every 6 batches. After calibration, discard the calibration solution that was used. You cannot re-use it.

To limit the amount of calibration solution required, we use our  1mL (1 cc) syringe (without needle) to fill the area in the black tip where the probe sits when the meter is stored. Make sure to use distilled or RO water to rinse off the pH meter probe and black tip and shake dry between calibration steps. Never touch the ball probe or attempt to dry it with a cloth or any other method that involves touching the probe. A good hard shake (like is done with an old fashioned mercury thermometer) is all that is needed.

Make sure to rinse the meter well before using to wash off all storage or calibration solution. Rinsing with regular tap water is fine if you intend to use the meter immediately.

There's no need to store the pH meter in pH meter storage solution in between measurements on brew day. After reading, simply rinse off the meter with distilled or RO water and shake dry. At the end of the brew day, rinse it again, fill the area in the black tip where the probe sits with the storage solution and close. You may see some white crystals form on the outside after a day or two. This is normal and can be left until next brew day. 

 

What about pH test strips?

Little pH test strips are also available that test in the important 4-7 pH range. So why not use pH test strips instead of a pH meter? There are many reasons: 

  • We test our pH quite often from the start to end of the brewing process from grain to bottle (often as many as 20 times when it's a new recipe) so pH test strips actually cost more in the long run. (Most home brewers that use pH strips only use them to measure mash pH, and while that's likely the most crucial point during the beer making process for an accurate pH level, it's not the only one).
  • Strips are not temperature compensated so samples must be cooled to room temperature before use. This greatly slows down the brewing process. Our pH meter is temperature compensated up to 140F.
  • pH strips are very slow to return a result. You have to wait until the colour stops changing which can take up to 10 minutes! A pH meter only takes seconds.
  • And most importantly: Strips are not as accurate. The colour gradients appear so similar that in practice you'll be lucky if you can even get to +/- 0.6 pH accuracy. Take a look at the picture below. It's the color coding to which you have to try and match what you see on the strip of paper. The colours look almost identical in the important 5.0 to 5.5 range making to hard to tell exactly what your pH actually is. A pH meter accurately measures down to a resolution of 0.01 pH and gives you the result in numbers, not ambiguous colours.

ColorpHast pH Strips (4.0 - 7.0 range):

Every brewer we know that bought a box of test strips still has most of them left as they have simply stopped using them.

Proper control of pH is a critical step to brewing any style of all-grain beer consistently and successfully. This simply cannot be done without an accurate method of measuring pH. We recommend the Hanna Phep 5 pH meter (model HI 98128).