Are you confident that you are accurately measuring the pH of mash in your brewing process?
We recently had a startup brewery approach us about finding the right pH meter and electrode for their process including measuring the pH of mash.
Find out what we recommended and why.
1. Background
Over the past 30 years, the number of home brewers and microbreweries has grown tremendously. Interest in the variety of beer types can be seen in the choices that are available to the consumer.
Often times brewers start by using a malt extract to prepare wort that is boiled before starting the fermentation process with yeast. The malt extract is prepared from natural grains such as wheat, barley, and rice.
More experienced or adventurous beer makers prefer to make their own malt extract. Crushed grains that have been allowed to begin to germinate and dried in a kiln are known as malt. The malt is extracted by steeping in water at 60 to 70°C (140 to 158°F) in a process known mashing. This is where the alpha and beta amylase enzymes are activated, converting the malted grains into fermentable sugars.
The pH of mash is a critical parameter to monitor; it must be maintained between pH 5.2 and 5.6 for optimum enzyme activity. As the malted grains are broken down, organic acids are formed which can lower the pH of the mash. This can result in incomplete conversion of starch to sugar, as amylase activity decreases at a pH less than 5.2.
As a result, pH should be measured and periodically adjusted, if necessary, throughout the mash process.
2. Finding the Right Instruments
A start-up microbrewery approached Hanna Instruments for a solution to monitor their pH in their incoming water, mash, wort, and finished beer. The brewer was particularly concerned about measuring pH in mash due to the high temperature.
He had two main concerns:
Temperature Compensation
The brewer was concerned about temperature compensation. Because of the high temperatures of mash, the pH observed will vary greatly with temperature.
This is an important consideration if using a pH meter without temperature compensation. A hot mash will read at a lower pH than a mash cooled to room temperature due to the variation in ion activity.
Meters with temperature compensation will display a reading unaffected by the temperature of the sample, providing users with an accurate pH measurement.
pH Electrode Lifespan
The brewer was also concerned about pH electrode lifespan. He recently read an article that noted how high temperatures can deteriorate pH glass.
3. Recommendation
Our technical team recommended the Beer Analysis pH Portable Meter - HI99151 with the pH Electrode for Beer Analysis - FC214D.
Automatic Temperature Compensation
The FC214D electrode features a built-in temperature probe, allowing for temperature compensation without requiring an additional probe.
Specialist pH Electrode for Beer
The FC214D is made with high temperature glass with a temperature range of 0 to 80°C (32 to 176°C), allowing it to be used at the elevated temperatures needed for mashing without shortening the electrode life.
The customer appreciated the durable titanium body and shield around the pH glass bulb of the FC214D.
Not only does this provide a rugged measurement solution, but the titanium body also transfers heat to the temperature sensor, enabling the user to obtain rapid results.
Ease-of-Use
The stability indicator let the customer know when the reading was stable, ensuring that the correct reading was always recorded.
Instructions for calibration are displayed on the main screen, which gave the customer confidence in calibrating the instrument.
Maintenance
The FC214D features a renewable cloth junction, allowing for easy clearing of debris that might clog the junction.
Because of the high levels of proteins in the grains, the HI7073L Cleaning Solution for Proteins (500 mL) was also recommended for periodic cleaning of the electrode glass and continued accurate measurements.
Overall, the HI99151 pH Meter for Beer Analysis was a perfect tool for their pH monitoring needs!
