The Assyrtiko is hand harvested when ripe but undergoes a variation on the traditional process. A portion of the grapes are sun dried in the strong Santorini summer sun while another portion is shade dried to maintain relative fruit freshness.
Once the berries have been sufficiently dehydrated by the sun, they are gently pressed over many hours until the last drop of the richly concentrated must is rendered. Yields at this stage are exceptionally low – less than 10 hl/ha. The must is then placed in old casks to undergo fermentation which stops once the alcohol level reaches 13 to 14%, thus giving a natural sweet wine. The wine is then left to age in the fermentation casks previously used for white wine production for at least 10 years in cask. Vinsanto by Gaia is bottled without any fining or filtration.