Understanding the process of water kefir fermentation and its progress can sometimes feel like a guessing game. You might find yourself wondering, “Is anything actually happening in my batch?” especially when visual cues are subtle or non-existent. The key to unveiling the facts lies in measuring the pH level of your water kefir—a straightforward, scientific method that offers a clear indication of fermentation activity.
During water kefir fermentation, a diverse community of microbes busily consumes sugar, producing alcohol, carbon dioxide, and organic acids. This micro-level activity transforms the sweet sugar water into the probiotic-rich drink we know as water kefir. However, since these processes occur on such a small scale, it’s impossible to observe them with the naked eye. This is where testing the ph of water kefir plays a crucial role.
A pH test removes all the uncertainty associated with trying to assess microbes with the naked eye. A pH test provides a scientific, quantifiable measure of fermentation. The starting pH for water kefir fluctuates as the water source’s pH will fluctuate from household to household. Generally speaking, the starting pH will range between 5.0 and 6.0 and higher. From here, during fermentation, the environment within your water kefir gradually becomes more acidic, typically dropping to around 3.5 as the microbes do their work. This does not mean that water kefir is ready once it reaches 3.5; it just means that it will continue to fall in time, but it’s up to you when you stop fermentation. The key here is a falling pH. So, as it ferments, acids increase, making it more acidic, which in turn lowers the pH value or number. Thus, a falling pH tells us that fermentation is occurring regardless of what we see. So, a decreasing pH value is a reliable indicator that fermentation is progressing as it should, offering peace of mind and a way to track the brew’s development beyond the often-used visual speculation.
Taking a pH reading of your water kefir is a simple and quick process. Here’s how to do it:
Before you start your batch and pH testing, confirm that you're setting the stage correctly for fermentation. Use filtered water and the right amount of sugar, and maintain an appropriate fermentation temperature. These factors significantly influence the fermentation process and, consequently, the pH levels.
You can find this information on our post here - How to Make Water Kefir.
Get a set of pH test strips that are designed to measure the acidity or alkalinity of liquids. We carry two different types for testing pH during fermentation, available here: pH test strips. Both options work great for water kefir. It just comes down to whether you want a roll of strips or individual test sticks, so it's a matter of preference. From here, don't overthink it, as they both do the same thing and will test the pH of your water kefir.
After you add the water kefir grains to your batch, wet a pH test strip with some liquid from your water kefir batch using a pipette or spoon—not the other way around. So, wet the strip instead of dipping the strip into the batch.
After a few seconds, the pH strip will change color. Compare this color to the chart provided with your pH strips to determine the pH level of your brew. Whatever color matches, the closest is the pH. Write this number down; this is the starting pH you will use later to refer back to.
Now that we have the starting pH of our water kefir, we can use this figure moving forward to see how fermentation progresses.
So, to track progression from here, we simply take another test after a period of time and compare the difference.
For example, it’s two days after we started our batch, and we think that nothing’s happening because we do not see anything visually. This is the perfect opportunity to take another test to determine what is going on at the microbial level.
Remember, a dropping pH level signals active fermentation but not necessarily readiness to drink. The beauty of water kefir lies in its versatility and adaptability to personal taste preferences. While the pH indicates fermentation activity, the best time to stop fermentation and move on to the next step depends on your taste preference. Some might prefer their batch to be less sweet, opting for a longer fermentation time, while others might enjoy slightly sweeter, shorter fermentation. In essence, pH readings offer a window into the microbial world of fermentation, ensuring that your water kefir is on the right track.
However, the decision on when it’s ready to drink is yours to make, based on your taste preference. This balance between scientific testing and personal choice makes home fermenting an art as much as it is a science. By adding pH testing into your water kefir-making routine, you’re allowing yourself a scientific way to test the progression of fermentation, so you don’t have to rely on subjective and unreliable visual indicators. After all, you can’t see microbes, so how would one be able to diagnose their health or activity with the naked eye? So, do yourself a favor and get some pH test strips.
