Pliny also discussed wine preservatives at some length, leaning heavily towards tree resins for that purpose. Chips of sweet-smelling wood, such as laurel, juniper, mastic, and terebinth, were added to the must before it was boiled. Pliny, like Columella, also was assertive about the need to ensure the cleanliness of amphorae before their first filling or their re-use.
"Immediately after the rising of the Dog-Star they should be coated with pitch, and afterwards washed with sea-water or water with salt in it, and then sprinkled with brushwood or else with potter's earth, and then sprinkled with myrrh, as should be done with the wine cellars also." (Pliny, Natural HistoryXIV.112)
Roman vintners often salvaged wine that was at the point of turning to vinegar by making it re-ferment on the dried and baked lees of good wine (Columella, On Agriculture XII.xxx). Only in the past century has this tactic been recognized as an effective one.