The determination of the Hartong at 45° is the most revealing result because at this temperature, the proteolytic and cytolytic activity of enzyme is maximum.
The Hartong 45° depends of :
- the barley variety from which the malt is made
- the state of malt disintegration
- the process of malting.

Scale of values:
< 30 bad. The abnormal weakness in enzymes generates difficulties of treatment at the time of the manufacture of the beer.
< 36 insufficient. The reason: a weakening of enzymes afterwards
- of a deficient soaking
- of malting with an exaggerated ventilation
- and a too elevated temperature
> 36 malt possessing a satisfactory enzymatic quantity
> 40 good. Malt rich in enzymes (good process to malting)

The brewer designates in the specification, the fork of tolerance of the Hartong 45°C.