Summer above 24 degrees: ready in 24-48 hours.
Spring and autumn 20-23 degrees: 2-3 days typically.
Winter below 20 degrees: 3-4 days.
Use pure vanilla powder with no added sugar or starch. If your vanilla powder contains other ingredients use pure vanilla extract instead.
Leave the nectarine skin on — it contributes a subtle tartness and a slightly deeper colour.
Vanilla sediment may settle at the bottom of the bottle — this is harmless. Strain when pouring for a clear result.