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A '''pH Meter''' is not only considered by some to be an essential tool for all grain homebrewing and commercial brewing, but is also a very useful tool to have for making sour beer. For examples of when an accurate pH reading is useful in the sour brewing process, see the [[Mixed Fermentation]], [[Wort Souring]], and [[Lactobacillus]] pages.

Higher end pH meters recommended by our members and others. "Benchtop" meters are generally higher end, and are good choices for professional brewers.

* Despite having an automatic calibration message, this pH meter still often needs to be calibrated before each brew day <ref name="ajdelange"></ref>.* The buttons have been reported to be touchy by some. * Poor instructions that come with the unit. Use [http://www.hach.com/asset-get.download.jsa?id=18952100085 the website manual] instead of the instructions that come with it.

====[http://www.milwaukeetestersmilwaukeeinstruments.com/MW102.html site/products/products/standardportable-meters/81-products-g-standard-portable-meters-g-mw102 Milwaukee MW102 pH/Temp Meter (updated/upgraded from SM101 and MW101)].====

Buffer solution will be required to calibrate a pH meter, and generally has to be purchased separately from the pH meter itself. In general, it is recommended that a pH meter have a 2 point calibration method, which requires 4.0 buffer solution and 7.0 buffer solution. Many buffer solutions for pH meter calibration can be found on [http://www.amazon.com/s/?ie=UTF8&keywords=ph+meter+calibration+solution&tag=googhydr-20&index=aps&hvadid=33870947755&hvpos=1t2&hvexid=&hvnetw=g&hvrand=2358411058820273529&hvpone=&hvptwo=&hvqmt=b&hvdev=c&ref=pd_sl_9h5a0pkyc9_b Amazon] or other retailers. Note that these buffer solutions do have expiration dates, and using expired calibration solutions can throw off pH meter readings. ==Testing the Probe==The probes on pH meters generally have a limited life, depending on the quality of the unit. Milwakuee Instruments describes the following method for testing the life of the probe: "A simple test can be performed using Windex glass cleaner with ammonia and white distilled vinegar. The procedure is as follows: Turn your meter or tester on and place the probe in white distilled vinegar which is acidic (2.4ph) and the reading will be from 2.3 to 2.5 but must be below 3.0 then go to the Windex with ammonia which is alkaline. Your display should move very quickly up the scale to 10.5 – 11.2 but must go above 10.0. If the probe slowly moves up the scale then it is time to consider replacing it. If it does not go below 3.0 pH in vinegar and/or above the 10.0 pH in Windex then probe is dead." <ref>[http://www.milwaukeeinstruments.com/site/pdf/pH_Application_Info.pdf Milwaukee Instruments pH General Information Sheet. Retrieved 4/30/2015.]</ref> ==Using a pH Meter==(This section in progress) * [http://accidentalis.com/measuring-mash-ph-in-practice/ "Measuring Mash pH in Practice," by Matt Crispen (a good general guide to using a pH meter).]* [https://www.morebeer.com/articles/understanding_ph_in_brewing "Understanding pH and It's Application in Small-Scale Brewing," by AJ Delange.]* Carbonic acid can affect pH readings. If testing a beer that has CO2 in it, either residual from fermentation or from keg/bottle carbonation, let the beer warm to room temperature and swirl the beer to try and get all of the CO2 out of solution before taking a pH measumrement <ref>[https://www.facebook.com/groups/MilkTheFunk/permalink/1153226544705558/?comment_id=1153275738033972&reply_comment_id=1153651057996440&total_comments=5&comment_tracking=%7B%22tn%22%3A%22R%22%7D Conversation with Gareth Young on MTF. 09/23/2015.]</ref>.