Brew Dudes

We take another closer look at water chemistry as it applies to home brewing beer. This time, we create an experiment using water and calcium sulfate, also known as gypsum. The set up is just like our last brewing salts experiment, where we tasted water with different concentrations and discussed our thoughts. We also have a bonus experiment at the end.

Let’s go!

Gypsum Experiment Set Up

As we did with sodium chloride and calcium chloride, Gypsum was added to water so we could taste what that compound imparts in terms of flavor and mouthfeel.

We have a control of plain spring water. Then, we have samples with different concentrations:

• 125 PPM
• 250 PPM
• 500 PPM
• 1,000 PPM

With each taste, we describe what we think of the experience. Mostly, it wasn’t great.

The Outcomes

When we looked at the samples, it was clear that there is a solubility threshold between 500 PPM and 1,000 PPM.

It was clear because the water was not clear.

Here’s the list of our taste observations at different concentrations:

125 PPM: Not very perceptible
250 PPM: Chalky, slightly soapy
500 PPM: More pronounced chalkiness
1,000 PPM: Overwhelming, quite powdery

The main takeaway from this experiment and the last one is how much brewing salts you need to add to your beer. If you are looking to treat your water, you have to add enough brewing salts to get to over 125 PPM.

Mike states that if you are looking to dial in a Chloride to Sulfate ratio, the numbers need to be in the hundreds to make a difference.

Bonus Experiment – Epsom Salt

Mike made another solution – just one – with Epsom Salt (Magnesium Sulfate). Tested at a concentration of 1,000 PPM, this sample helped us compare to the calcium sulfate experiment. Surprisingly, even at the high end of our concentration level, the Epsom Salt has a minimal impact on taste. We’re not sure if we would add this brewing salt to more of our beers but the outcome was still interesting.

BREW ON!

We do science with Mike in this post. The topic of water chemistry and how it affects homebrewed beer continues to be intriguing. In this experiment, we set up water samples with different concentrations of “brewing salts” – sodium chloride, which is table salt, and calcium chloride. With five glasses in front of each of us, we learn at what concentration (Part Per Million level) can we really detect the added compound in the water. See the video to get the results!

The Set Up and Process

The first experiment is built to help us understand when we can detect table salt in water. Before the camera started to roll, Mike set up 5 glasses of water. Four of these glasses had salt added to them with one left alone as a control of sorts.

The four samples with salt had increasing amounts. Mike measured out the concentrations so that we could know the amounts in parts per million or PPMs for each sample. The breakdown of concentration are as follows:

Sample 1: Plain Spring Water – very little NaCl in it ~1 PPM
Sample 2: 125 PPM of sodium chloride.
Sample 3: 250 PPM of sodium chloride.
Sample 4: 500 PPM of sodium chloride.
Sample 5: 1,000 PP< of sodium chloride.

We tasted each in ascending order to experience the increasing salt amounts and comment on the flavor of the water.

Then, Mike set up the experiment again but swapped table salt for Calcium Chloride. The same PPM concentrations were followed for this second experiment.

Brewing Salts Experiment Outcome

The table salt titration experiment helped us to get a sense of how the increasing concentrations in the water sample would play out in our “tasting flight”. With that experience, it helped us with one of the more important brewing salts to our homebrewing practice: Calcium Chloride.

Our takeaway from the CaCl2 experiment is that we will push for a minimum of 125 PPM of calcium in brewing water. Lesser calcium concentrations below that threshold (50 to 100 PPM) didn’t impart flavor. Thinking about our beer brewing practice, we will start with a minimum of 120 or 125 PPM of calcium in the water to ensure a perceptible impact on the beer’s flavor profile.