Which OG to trust more?

[Alex4mula]

I have a regular glass hydrometer, a refractometer and a Tilt. I did an extract Irish red ale brew on Saturday that have an expected 1.052 OG. When I measured the OG the glass one measured 1.050, the refractometer showed 1.053 and the Tilt 1.045. All of these measure exactly 1.000 on 60°F distilled water.

 

[OSULumberjack]

Are you topping up with water after a partial boil? It can be hard to get the wort to fully mix, so that could cause different samples to read different values.

I have also heard that tilts can be a bit unstable in any particular measurement. I would trust the other two more, but that is gut reaction as I have no experience with the Tilt myself.

 

[Alex4mula]

Are you topping up with water after a partial boil? It can be hard to get the wort to fully mix, so that could cause different samples to read different values.

I have also heard that tilts can be a bit unstable in any particular measurement. I would trust the other two more, but that is gut reaction as I have no experience with the Tilt myself.

No topping up on this one.

 

[RM-MN]

I would trust the glass hydrometer. The refractometer is pretty close, close enough for most beers. I'm not at all confident in the Tilt.

 

[cnash]

Make sure you are correcting the hydrometer for temperature. For Example: Wort at 90 degrees F with a 1.055 reading on a refractometer will show a reading of 1.052 if your hydrometer is calibrated at 68 degrees F, but with adjustment it is 1.055.
Tilt may need to be re-calibrated. I don't have one but I plan to get one, not for accurate gravity but for tracking the end of fermentation.

 

[Alex4mula]

All readings in all devices were taken at same beer temp of about 68°F. The Tilt was similarly off (lower) on my previous brew. I think I trust more the glass one for sure. I like the Tilt to track fermentation progress and beer temp. This one is going well

 

[Northern_Brewer]

Even if the beer is at the same temperature, you should still be correcting back to the calibration temperature (typically 20°C for glass hydrometers) as they will respond in different ways to temperature.

Showing that they read the same in water is only one data point, you need to test them in eg 10% sugar water at the calibration temperature to really get a handle on them.

 

[BarleyStanding]

I use a refractometer most of the time; as long as I'm close, I don't sweat it being off 3-5 points and I don't cross reference with another instrument. When I have to get an accurate reading, I fall back to the glass hydrometer.