Klosterneuburg must weigher

The Klosterneuburger Mostwaage  ( KMW ) is a countersunk spindle for measuring the sugar content of grape must in percent by weight (g / 100 g). Your scale shows Klosterneuburg sugar degrees ( ° KMW ).

Since the presumed content of sugar-free extract has been deducted from the start, the values ​​displayed are only correct with a sugar content of around 20% and a sugar-free extract content of 3%. If the sugar content is higher, the scales will show values ​​that are too low, and lower values ​​that are too high.

The Klosterneuburger Mostwaage was the first director of the oenological - Pomological Institute in Klosterneuburg ( Federal College and Federal Office for vineyards and orchards ), Baron August Wilhelm von Babo , 1861 in the Austrian wine-growing introduced and later by the Italian viticulture as Babo degrees taken.

International use

For the must weight, i.e. H. the sugar content of the juice, different units are used internationally. The Klosterneuburg sugar grades are mainly used in Austria , Italy , Hungary , Slovakia and the states of the former Yugoslavia , i.e. the sphere of influence of the former Austria-Hungary .

The degree Oechsle is used in Germany , Switzerland and Luxembourg . 1 ° KMW corresponds to 4.86 °  Oechsle .

In France , Portugal and Spain, however, Grad Baumé is in use.

Conversion to volume percent alcohol

During the fermentation process, sugar is converted into alcohol and carbon dioxide in approximately equal parts by weight . Therefore, if all fermentable must components are fermented, the alcohol content in vol .-% can be calculated from the original sugar content in degrees KMW as follows ( formula 1 , simple approximation):

${\displaystyle {\text{Vol.-}}\%\,\mathrm {Alkohol={\frac {1{,}267\cdot ^{\circ }KMW}{0{,}267\cdot ^{\circ }KMW+200}}\cdot 100} }$

A better approximation is achieved with the following formula 2 , which is officially used by the Lower Austria provincial government :

${\displaystyle {\text{Vol.-}}\%\,\mathrm {Alkohol={\frac {1{,}267\cdot (0{,}71173\cdot ^{\circ }KMW-2{,}55)}{0{,}267\cdot (0{,}71173\cdot ^{\circ }KMW-2{,}55)+100}}\cdot 100} }$

Comparison table of approximation formulas

° KMW	Alcohol content % by volume according to Formula 1	Alcohol content % by volume according to formula 2
5	3.1%	1.3%
10	6.3%	5.7%
17th	10.5%	11.8%
18th	11.1%	12.7%
19th	11.7%	13.5%
20th	12.3%	14.4%

References and comments

1. ↑ Since Grad Baumé was excluded from the legal units in France by Decree No. 61–501 of May 1961 on units of measurement and control of measuring instruments, the French regulation refers to the sugar content, expressed in grams per liter.