Another refractometer question

[BigNastyBrew]

So, I just bought it and thought I calibrated it. It's the one from Williams Brewing that it is ATC. Really? I calibrated it to 0° on 68°F tap water and with a 1.032 wort, I noted it was at 8 brix. My OG the other day was 1.042 but the refractometer said 11 brix. This was at 71°F. Am I missing something?

[ApexBrewing]

Should have been just over 10 Brix. My vote is you read it wrong or something funky happened.

[Bugeater]

You should do the calibration with distilled or RO filtered water. The ions in most tap water will throw the reading off. This may account for some of the difference.

Wayne

[BigNastyBrew]

I DID calibrate it to 0 with distilled water at 68°. Then took my starting gravity when I brewed the other day at 1.032 and it read 8 Brix. Right on the freaking money. I'm going to calibrate it again. I still have a ton of distilled water left.

I'm down to "I read it wrong."

Thanks

[whiteManCanHop]

i may be wrong about this.... but i have found that the ATC feature more so applies to the temperature of the refractometer itself more than the liquid you are measuring. if your refractometer is really cold it will throw off the reading. i used to leave my refracto out in the cold garage and struggled with inaccurate readings. now it stays in my back pocket (where it stay nice and warm) on brew days and no more problems with inaccurate readings.

[BigNastyBrew]

Hmm....good tip. I'm wondering though if the differential in temperature makes no difference. Refrsct cold, wort warm or refract warm, wort cold...

[Mylo]

now it stays in my back pocket (where it stay nice and warm) on brew days and no more problems with inaccurate readings.

Be careful you don't sit down too fast...




Mylo

[whiteManCanHop]

Hmm....good tip. I'm wondering though if the differential in temperature makes no difference. Refrsct cold, wort warm or refract warm, wort cold...

remember, the drops you put on the glass will acclimate very quickly to the temperature of the refractometer itself. hot or cold liquid will have little chance at combating the thermal mass of the refracto... so imo there would be a difference.