Futura is an effective PET-NAT. No ads of sugars and yeasts for the refermentation but must. When in October we do the harvest of Trebbiano Spoletino to produce Il Reminore, we freeze a small part of that must for 2/3 months. On Genuary, after a correct rest we add this must in percentage. On Spring, while the temperature are mitigated the fermentation restart in a natural way.