Refractometers

[Brew_DD2]

The refractometer I have ordered is marked in SG and supposedly temperature compensated (?). Will it still need any conversion calcs?

Only for final gravity. You just dial in what you see into brewers friend (or any other site with a calculator) and it'll correct for the presence of alcohol.

 

[Harry Bloomfield]

So, if I'm understanding it correctly - there is no point in my just taking an SG reading towards the end of the fermentation process with a reflectometer, I must take one at the beginning as the reference, then use the above chart to work out the correction when a later SG is taken with the reflectometer.

Have I got it right now?

 

[Brew_DD2]

You take one at the start so you know much sugar you have in solution. You take a reading at the end to see how much sugar you have left. A refractometer reading near the end will.need a small correction as they don't read accurately in the presence of the alcohol.

The differential between your starting gravity and the final gravity will tell you how much alcohol your beer has. )The alcohol by volume)

 

[Drunkula]

- there is no point in my just taking an SG reading towards the end of the fermentation process with a reflectometer, I must take one at the beginning as the reference, then use the above chart to work out the correction when a later SG is taken with the reflectometer.

If you''ve got an original gravity reading with a hydrometer or refractometer you're good to take later refractometer readings. It's the original gravity before there's any alcohol that lets you use the correction factor.

 

[Harry Bloomfield]

If you''ve got an original gravity reading with a hydrometer or refractometer you're good to take later refractometer readings. It's the original gravity before there's any alcohol that lets you use the correction factor.

Thanks both, yes I logged a reading with the hydrometer at the beginning of the fermentation process, then checked and logged it for the second time on Monday. I calculated it as 8% my wine is still busy bubbling after 11 days - so I have left it for now..

 

[Harry Bloomfield]

My ordered reflectometer arrived a couple of hours ago, so I have been putting it to the test. This one...
https://www.ebay.co.uk/itm/153701254571

I must say I am very impressed with just how easy to read it is, when compared to an hydrometer. I checked the initial calibration with some water I distilled (as the instructions suggested) and with water straight from the tap - both were spot on zero. I took a sample of my recently finished white wine which I knew had a hydrometer reading of a fraction under 1.000. I couldn't make any sense of the graph above method so I fed the OG of 1.080 and the final Brix of 7 into the calculator here.. https://www.brewersfriend.com/refractometer-calculator/

I had a already calculated the ABV as 10.5 using my hydrometer OG and FG.
The above calculator suggested it was 10.52%