Extech Instruments, a FLIR company, sent us a refractometer to review and test out. In this video, we take a look at the device itself and all of the stuff that came with it. Then, we talk about how we would use it in our brewing at home.

A Refractometer And Its Accoutrements

I have been wanting to get a refractometer for a while now (I got the grain mill instead). Once Extech reached out to us, I was excited to check it out.

After opening up the package and taking everything out, I was surprised to learn that the refractometer itself was unusually heavy for it size. It felt like a well made, solid instrument when I picked it up for the first time.

It came with a number of different things to help you use the refractometer correctly.

  • A little hanky to swipe down the plate and tray where you drip wort to observe its gravity
  • A pipette to collect and drip wort
  • A small screwdriver to calibrate the refractometer
  • A tiny container of distilled water for calibration purpose

Mike’s thought on the distilled water was that one’s tap water would be a better source to calibrate your device since it would be the base of your wort. I used the distilled water first, turned the screw to set the refractometer to zero, and then tested my wort. After I cleaned off the plate, I used my tap water and it didn’t need adjusting so it was pretty much the same.

What You Need to Know about ATC

Automatic Temperature Compensation or ATC is a feature of this refractometer, which means the instrument will give you an accurate reading of your wort’s gravity at any temperature. Other instruments, like a hydrometer, are calibrated to a certain temperature – meaning that, one’s wort needs to be at a certain temperature to get a good reading. The refractometer with ATC doesn’t care about temperature.

With that, I was wondering how the device compensated for wort at any temperature. They responded to my query with this message:

ATC uses bimetallic strips like a thermostat that expand or contract with an increase or decrease in temperature and moves the focus point on the scale to compensate for the difference in temperature from 20°C (68°F) which is the null point (zero reading) on most refractometers to the actual temperature of the instrument. Note that ATC does not compensate for the temperature of the liquid measured, but for the temperature of the refractometer.

So the ATC is really compensating for the temperature of refractometer, which may be affected by the hot wort.

Three cheers for bimetallic strips.

Anyway, cool stuff. Thanks for letting us review your refractometer.

Brew ON!