Refractometer and must chunks

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Sep 2, 2020
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Ok, so admittedly this is a basic question. I've been using my refractometer to measure beer SG quite a bit and it's been working fine. Now I'm trying to measure my first wine during fermentation while the skins are still in the mix. The problem I'm having is that between back-to-back measurements I'll see the value vary as much as 3°. I think the problem is that I get little chunks in there. Is there a trick to stealing wine and avoiding all the chunks? Or some other trick to getting accurate SG measurements with my refractometer?


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Jul 10, 2012
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Saratoga Springs
You should not have any "chunks" sitting on the glass surface of your refractometer. How are you dripping a drop or two onto the glass? A very small pipette will do the trick or perhaps one of those plastic straws you get at some coffee shops to stir your coffee or even an eye dropper. None of these will be large enough to permit any solids to be collected.
BUT... a refractometer is not calibrated to give you an accurate reading when the solution has any alcohol in it. Light refracts (bends) when it travels through water at a different angle than when it travels through alcohol. There are calculators to compensate for the amount of alcohol but the best time to use a refractometer is when you are measuring the sugar content of fruit or must prior to pitching yeast.