Weighing In On Austria's Must-Have Weight Scale

The Klosterneuburg Must Weight Scale (KMW) is used in Austria to determine the must weight of grape juice. Must weight is a measure of the amount of sugar in grape juice, which indicates the amount of alcohol that could be produced if it is fermented. KMW measures the exact sugar content of the must, with 1°KMW equalling 1 gram of sugar per 100 grams of grape must. This scale is important for Austrian wine classifications, which are based on grape ripeness (must weight).

Klosterneuburg Must Weight Scale (KMW)

The Klosterneuburg Must Weight Scale (KMW) is an Austrian unit of measurement for determining the relative density or specific gravity of grape must. This expresses the mass (weight) in relation to the volume. The mass, also known as extract, consists of the dissolved substances such as fruit pulp particles in the grape must. These are mainly sugars (fructose, glucose), but also acids, minerals, phenolic compounds, proteins and others (some of these substances are then found in the total extract of the wine). The specific gravity of grape must is always greater than 1.0 (water), and the difference is largely due to the sugar content.

The KMW scale was developed by August-Wilhelm Freiherr von Babo (1827-1894) in 1861 at the Klosterneuburger Weinbauinstitut (Lower Austria). It is based on the saccharometer invented by Carl Joseph Balling (1805-1868). The KMW scale is calibrated to a temperature of 20 °C.

The KMW measures the exact sugar content of the must. One KMW is equal to 10 grams or 1% sugar in 1000 grams of must. It is also known as the Klosterneuburger Mostwaage in German. The weight of the must is measured as 1 gram of sugar per 100 grams of grape must. One degree KMW roughly equals five degrees Oechsle.

The KMW scale is mainly used in Austria, Hungary, Italy and some Eastern European countries. The method of measurement can be carried out by means of areometer (plummet scales), pycnometer and refractometer (light refraction).

KMW measures sugar content

The Klosterneuburg Must Weight Scale (KMW) is used in Austria to determine the weight of must, or grape juice. It is a unit of measurement that represents the relative density or specific gravity of grape must, expressing the mass (weight) in relation to the volume.

KMW measures the exact sugar content of the must. The weight of the must is measured as 1 gram of sugar per 100 grams of grape must. One KMW is roughly equal to 5 Oechsle, a unit of measurement used in Germany, Switzerland, and Luxembourg. The Oechsle scale measures the density of grape must, which is an indication of grape ripeness and sugar content used in winemaking.

The KMW scale is calibrated to a temperature of 20°C. The exact conversion of KMW to Oechsle is:

> KMW x (4.54 + 0.022 x KMW)

This can also be roughly calculated as KMW x 5. The KMW method was developed by August-Wilhelm Freiherr von Babo in 1861 at the Klosterneuburger Weinbauinstitut in Lower Austria, based on the saccharometer invented by Carl Joseph Balling.

KMW conversion to Oechsle

The Klosterneuburg Must Weight Scale (KMW) is a unit of measurement used in Austria, Hungary, Italy and some Eastern European countries to determine the must weight of grape juice. Must weight is a measure of the amount of sugar in grape juice, which indicates the amount of alcohol that could be produced if the sugar is fermented.

The KMW scale is calibrated to a temperature of 20°C and measures the exact sugar content of the must. The weight of the must is measured as 1 gram of sugar per 100 grams of grape must.

The Oechsle scale, on the other hand, is used in Germany, Luxembourg and Switzerland. It is an important part of the German wine classification. One degree Oechsle (Oe) is defined as the increase in weight of 1000 millilitres of must by 1 gram.

To convert KMW to Oechsle, the following formula can be used:

> (0.022 x °KMW + 4.54) x °KMW = °Oechsle

This formula takes into account the difference in calibration temperatures between the two scales. The KMW scale is calibrated to 20°C, while the Oechsle scale is usually calibrated to 17.5°C.

For rough calculations, a simpler conversion can be used:

> KMW x 5 = °Oechsle

This conversion factor is based on the approximation that 1 °KMW is roughly equal to 5 °Oechsle.

It is important to note that the resulting values from these conversions will not be absolutely precise due to the different principles used by each scale to determine sugar content. However, for practical purposes, these conversions are sufficient.

KMW used in Hungary, Italy and Eastern Europe

The KMW (Klosterneuburg Must Weight Scale) is a scale for measuring the weight of must (grape juice) in winemaking. It is primarily used in Austria, but it is also used in other wine-producing regions such as Hungary, Italy, and Eastern Europe.

In Hungary, the KMW scale is used to measure the sugar content of grape must during the wine-making process. This helps winemakers determine the potential alcohol level and sweetness of the final product. Hungary has a long history of winemaking and is known for its diverse wine regions, including Tokaj, Villány, and Eger.

In Italy, the KMW scale may be used in some wine-producing regions, particularly in the north of the country. Italy is renowned for its wine culture and has a wide variety of indigenous grape varieties. Italian winemakers pay close attention to the sugar content of their must, as it plays a crucial role in the fermentation process and the resulting wine style.

Eastern Europe, a subregion of the European continent, includes countries such as Belarus, Russia, Ukraine, Moldova, and Romania. This region has a rich history of winemaking, with viticulture and wine culture playing a significant role in the traditions of the region. While the specific use of the KMW scale may vary across Eastern European countries, it is likely employed by winemakers to measure must weight and determine the progression of the fermentation process.

The KMW scale measures the weight of must as 1 gram of sugar per 100 grams of grape must. This measurement is important for winemakers as it helps them monitor the fermentation process and make adjustments to achieve the desired wine style. The scale is an essential tool in winemaking, providing valuable data that influences the entire production process.

KMW and Austrian wine classification

The KMW (Klosterneuburg Must Weight Scale) is a measurement of the amount of sugar in grape juice (must) and is used to determine the potential alcohol content of the grape juice if it were to be fermented into wine. KMW is the primary measurement of must weight in Austria, where it is known as Klosterneuburger Mostwaage.

One degree KMW means there is 1 gram of sugar per 100 grams of grape must. The KMW scale is calibrated to a temperature of 20°C. The KMW scale is also used in Hungary, Italy, and some Eastern European countries.

KMW is used in Austrian wine classification, which has three official tiers: Prädikatswein, Qualitätswein, and Landwein. Prädikatswein is the top tier of Austrian wine classification and is further divided into seven types of wine, or Prädikat, based on grape ripeness (must weight). The ripeness of grapes is measured using the KMW scale. The seven types of Prädikat wines are:

• Spätlese: made from grapes picked at least a week after the start of the standard harvest, with a minimum of 19 KMW.
• Auslese: made from ripe grapes (minimum 21 KMW) affected to some degree by botrytis.
• Beerenauslese (BA): made from super-ripe grapes (minimum 25 KMW) that remain on the vine and are selected only if affected by botrytis.
• Ausbruch: made exclusively from botrytis-affected berries.
• Trockenbeerenauslese (TBA): made from grapes left on the vine until they reach a botrytized and raisin-like state, with highly concentrated sugars (30 KMW).
• Eiswein: made from grapes (minimum 25 KMW) that were harvested and pressed while naturally frozen.
• Strohwein / Schilfwein: made from grapes (minimum 25 KMW) that are air-dried, traditionally on mats made of straw or reeds, to concentrate their flavours and sugars.

Frequently asked questions