It was preserved. You ever watch someone preserve foods? My aunt preserved many foods. After boiling, she would put the food in a jar. She would then seal the jar and the food could sit on a shelf for a year or more without going bad. Ancients used the same techneques for preserving their wines in their unfermented state. They would boil them, put them in wine bottle, seal the bottles and shelf them. Cato, Aristotle, Pliny the Elder, Columella all recorded this technique in their writings from the first Century AD and earlier.
So that it would not ferment.