We use immature grapes of the Grüner Veltliner variety for our Verjus. The harvest of the green grapes with about 4 °KMW (equivalent to about 13 – 14 g / L sugar) takes place early in the morning (4 o’clock in the morning) on a July day. It is important here that all grace periods of the plant protection products used, which are approved in biological cultivation management, are respected. No copper or sulphur may be used between 28 and 21 days before harvest. Therefore, some years may not be suitable for the production of verjus. In years of high fungal pressure, plant extracts, teas and baking powder may not be sufficient to keep the grapes healthy and then a later harvest time for the verjus would have to be chosen. At this later date, however, sugar levels must not have risen too high. Because then you harvest grape juice and no more verjus.
The preservation of acidism is therefore the great challenge in the production of verjus. The acidic juice is processed as follows. Hand reading in buckets, transport to the cellar in 400 kg boxes, squeeze without dissteming, squeeze out in the pneumatic press with whole grape range. The juice is coated with dry ice to the oxygen exclusion and 0.1 g/L pectolytic enzymes are added. These serve to digest the tannins in the juice and help with the clarification. Then bentonite (alumina for precipitation of the thermolabilic protein) is added, which does not cause any residues and helps the juice to become clearer. After cooling to 0°C (for the weinstein precipitation), the juice is removed from the trub and heated without filtration and filled hot with 76°C (5 minutes core temperature). This will stop microbiological corruption. Our verjus can have a slight trub in the bottle, which is quite natural and comes from the pulp, which was still in limbo at the time of the filling. Either shake before use or, as with decanting wine, carefully pour out the clear liquid and leave the trub in the bottle.
