In order to prevent unwanted microbiological activity during grape picking and in the mash tank, the temperature of the berries is reduced. Refrigeration units could be used for this purpose, but cooling with dry ice is particularly recommended.
The grapes can be mixed with dry ice snow via cooling lances after being crushed in the mash tank, or dry ice pellets are added to the tank manually. Thus, the mash is cooled from the inside and is kept at the desired temperature. By cooling with carbon dioxide, yeasts are hindered in their activity. Moreover, the liberated carbon dioxide gas displaces ambient oxygen and prevents further oxidation.
Mash cooling with dry ice offers in particular the following advantages:
- By deliberately influencing maceration times, more of the desired contents, such as fruit and colour materials, are extracted from the grape skin and the fruit pulp
- Very gentle treatment of the mash
- Sulphurisation can be kept to a minimum
- Efficient and rapid cooling
- Displacement of ambient oxygen
- Maximum removal of dissolved oxygen
- User-friendly operation
- Low space and personnel requirements
- Low maintenance costs
- Favourable operating costs
Messer will assist in the selection of the process and the provision of the necessary technical equipment as well as the required carbon dioxide.