Re: Sugar Measurement

Got my $39 refractometer and can't believe these things used to cost > hundreds.
> > I was hoping someone would crunch my numbers and see if they make sense. > > I took a 10 ml sample of raspberry wine and measured: > > Alcohol: 15% on alcolimiter or whatever that glass thing is called. > Brix: 11% on refractometer > > I then boiled it for 5 minutes, reducing it about 50% then added distilled > water to 10 ml. > > Refractometer then read 6% and the alcohol read 1% > > I was surprised to see the brix drop so much but I have no feel for this. > > js

For your alcohol measurement, are you talking about a vinometer? If so, I think they do not give good numbers if there is sugar present. Now, the refractometer --- it is also affected by the alcohol present. Thus, the numbers will be off.

Hmm, these are calibrated on dry wines. To be honest, I have never used them so I don't can't say much more than I have read. Maybe you could test it out with some wines of different alcohol/sugar contents and see how off the calibration is? This may not be linear.

I certainly did read your post. You were surprised to see the numbers change so much when compared BEFORE and AFTER boiling. Of course your refractometer reading will be different after boiling. The alcohol is gone and you have a different amount of water present. How much light is refracted will depend on all the components -- changing ethanol to water is a large change in the refractive properties of the solvent, which is how you are indirectly measuring sugar content.

Recently someone posted a link (can't find it now of course :-) with informatinon on how to correct for these errors. It was recent in one of the refractometer threads.