Every brewer tastes their beer. They should. But judging carbonation by mouthfeel and then adjusting the tank based on it is how a small problem turns into a bad batch.
A real example
In our high-starting-pressure plot, the tank started a carbonation run at 7 PSI when it should have been close to zero. The beer finished under-carbonated. We don’t know whether it was checked with a shaker or just by mouthfeel, but it tasted flat. So the target was raised from 3.0 to 3.3 volumes and the tank ran another couple of hours.
Our read is that the beer was probably still under-carbonated at the end, because the real cause, the starting pressure, was never fixed. Tasting found a symptom. Turning the dial treated the symptom. Nobody measured the cause.
Why taste misleads
Perceived carbonation shifts with serving temperature, glassware, how the beer was poured, and what you tasted just before. A beer can feel flat in a warm sample cup and lively in a cold glass. None of that tells you how many volumes are in the tank.
Even instruments disagree, which is the point
Here’s the honest part: measuring CO2 isn’t simple either. Every common method works from the pressure CO2 produces at a known temperature and calculates the CO2 content from there. A critical review presented at the 2012 World Brewing Congress found that ASBC, EBC, the Brewers Association and instrument makers each use different equations, so the same pressure and temperature can give significantly different results (Hutchinson, ASBC 2012).
That’s not a reason to give up on measurement. It’s a reason to measure the same way every time, so a change in the number means a change in the beer.
What good looks like
One of our customers checked FizzWizz’s carbonation against an Anton Paar CO2 meter:
“It taught me that my head pressure gauges are slightly off and it seems accurate with the carbonation.” Evan Cronshaw, Whitetooth Brewing Co.
That’s the habit we’d recommend: pick a method, use it on every batch, and trust the trend.
Taste for flavour. Measure for numbers.
Keep tasting. Use it for flavour, aroma and balance. But when you’re about to change a tank’s target because something feels off, measure first. And check the basics before you blame the setpoint: the starting pressure, the temperature probe, and a clean stone.
Sources
- When Your Carbonation Plot Starts Too High.
- Donald J. Hutchinson, The measurement of carbon dioxide in packaged beer: A critical review, ASBC, 2012 World Brewing Congress.
- FizzWizz Testimonials (Whitetooth).