The popularity of home brewing has grown tremendously during the past years: now walking down the street, one can smell the tempting aroma of freshly brewed beer from nearly every Australian garage. While every brewer is part artist, and is proud of their creations even if they are far from what was expected, pouring spoiled batches into a sink can cause them to explore the use of scientific analysis to control the brewing process.
One of the most important parameters to be monitored in brewing is pH. pH control is important at any stage, starting from incoming water analysis, through mashing and fermentation, to testing the final product.
Everything starts from water. Two brewers in different regions, following the same brewing steps with the same ingredients, will never get the same final product, just because they have different quality of water running from their taps. Understanding the starting pH of water will help to find out whether any adjustments have to be done to achieve a great result. Ideally, the pH of incoming water shouldn’t be higher than 9, otherwise adjustments can be so great that flavour can be affected from the addition of acids and chemicals.
While the beginners usually start by using commercial malt extract to prepare wort that is boiled before starting the fermentation process with yeast, more experienced and adventurous brewers prefer to create their own malt extract in a process called “mashing”. During this process the enzymes converting the malted grains into fermentable sugars are activated. The pH of mash is a critical parameter to monitor; it must be maintained between pH 5.2 and 5.6 for optimal enzyme activity and to avoid the appearance of undesirable off-flavours. In order to achieve this it is important to both know and treat your incoming water to help the end result achieve the 5.2 pH range. This can be done naturally through the acids present in the wheats or by using lactic acid.
Once a brewer understands the importance of monitoring and adjusting pH during the brewing process, he comes to a difficulty of choice between test strips and a pH meter. Test strips seem to be cheaper and easier to use, however, many brewers decide to switch to a pH meter before their first box of strips comes to an end. Why? Colour grades seem to be so similar on the strips, that one is very lucky when achieving a 0.6 accuracy with it! So, getting the great taste becomes the same lottery with the strips, as when not measuring pH at all!
When finally coming to a decision to purchase a pH meter, another question to consider is: “Do I need a meter with the temperature compensation, or will a simple one do the job?” Due to the variation in ion activity, pH is a temperature-dependent parameter and varies greatly with cooling or heating. For example, a hot mash will read at a higher pH than a mash cooled to room temperature. This is why temperature compensation is an important feature to consider: meters with temperature compensation will display a reading unaffected by the temperature of the sample, providing with an accurate measurement.
Taking all mentioned above into consideration, our team (as well as the most of the brewing Internet resources) recommends the HI98128 pH tester from Hanna Instruments as a “must have”. This tester is waterproof, has a 0.01 resolution and automatic temperature compensation. It can be calibrated with 2 points: pH 4 and 7 for mash and finished beer analysis, and pH 7 and 10 to test the water if needed.
All that you need is just to clean it often in a cleaning solution, put a little sponge and some storage solution into a cap to keep an electrode hydrated when it’s not in use, and don’t forget to calibrate it regularly. And enjoy your that very special taste, that will now be repeatable and predictable for every batch!