Measuring Sweetness in Grapes

Sugar is not everything, of course - but the must weight, i.e. the sugar content of the grapes at harvest, is definitely a decisive criterion when it comes to the perfect time to harvest!

🧐 Why is that? Well, without sugar there is no alcohol - the must weight therefore helps to determine how much alcohol a wine will later have and is therefore also decisive for the wine style. This is precisely why most wine-growing regions, especially in Europe, have so-called minimum must weights - the wine law specifies exactly how much sugar the grapes must contain for which wine.

The sweetness in grapes, meaning the sugar content, is measured with a refractometer, which you may already know from the last post, or it is determined in the laboratory. However, the unit of measurement in which the result is expressed varies from country to country:

🍇 In Germany and Switzerland, they measure in Oechsle.

🍇 In other European countries and in Australia, Baumé is commonly used.

🍇 Brix is common in the United States and South Africa.

🍇 In Austria, the Klosterneuburger Mostwaage (KMW) system is used.

A calculation example: 13 vol. % = approx. 100 Oechsle = approx. 13 Baumé = approx. 23.4 Brix = approx. 20 KMW 💡

Phew, do you have to remember all that now? No, fortunately not - that's why there are clever charts that winemakers also use to look it up 😉

The important thing is: determining the must weight, in whatever unit of measurement, is a decisive step on the way from grape to wine!