International Code of Oenological Practices

Download document

Control of the sugar content of grapes

II.1.9 Control of the sugar content of grapes


An increase in the natural sugar content of grape berries by viticultural techniques.


To achieve an optimal composition of the crop by moderating yield and controlling vigour.


The objective can be reached by a choice of different factors such as:

a)        Soil and climate,

b)       Varieties, clones and rootstocks,

c)        Optimum planting density and vineyard management,

and by the application of the following viticultural practices:

  • Balanced loading of buds on the vine,
  • Maintenance and moderate fertilisation of the soil,
  • Performing the operations of the annual vegetative period of the vine at an opportune time, without excessive trimming,
  • Supplementary irrigation in dry zones,
  • Occasional thinning of bunches,
  • Reasonable use of pesticides,
  • Harvest at optimal maturity,
  • Natural raisining on the vine, late harvesting.

Recommendation of OIV: