The high acidity in Mustang Grapes can cause severe skin irritation until the acidity is corrected. For that reason, wear rubber gloves when picking, handling and squeezing these wild grapes. The gloves will also keep your hands from staining purple. In my area of south central Texas, the Mustang Grapes ripen and begin to fall from the vines by late June. We harvested our first lot 20-21 June and our last on 5 July and started 15 gallons of wine in three batches.
Mustangs are very acidic, tart and almost impossible to eat with any degree of enjoyment.
Indeed, their acid is so strong it can burn the mouth. It therefore surprises many that Mustang Grapes make such outstanding wines. Their natural sugar is insufficient to make a self-preserving wine and must be supplemented, but many native grapes suffer a low Brix. Notwithstanding the displeasure some winemakers have regarding water dilution and sugar addition, the resulting Mustang wine is often outstanding. This does not surprise Texans, but outsiders who taste the grape are usually astounded by the wine.