Photometer for Reducing Sugars in Wine

This Hanna Instruments photometer measures residual reducing sugars in wine.

Why it is measured

Residual sugar decides whether a wine is dry or sweet, whether fermentation has actually finished, and whether a bottled wine will referment. A hydrometer cannot answer it near the end, because alcohol and sugar pull the density in opposite directions.

Where it is used

• wineries
• fermentation monitoring
• pre-bottling checks
• juice and must analysis

How a photometer differs from a strip

A photometer runs the same colour chemistry a test strip does, but reads the colour with a light source and a detector instead of an eye. That turns a range into a number, and a number into something that can be recorded, trended and defended.

It costs more, needs reagents and needs clean cuvettes. It earns that back wherever the result has to satisfy somebody other than the person who took it.

Practical note

Filter or centrifuge a cloudy sample first; suspended solids absorb light and read as sugar that is not there.

Supplied as one model.