Sottoli (preserved under oil) and sottaceti (preserved under vinegar) are the twin pillars of Italian vegetable preservation—the techniques of submerging blanched, grilled, or raw vegetables in extra-virgin olive oil or wine vinegar to create shelf-stable antipasti that capture peak-season vegetables for year-round consumption. The sottoli tradition is one of the foundations of the Italian antipasto table: jars of artichoke hearts, sundried tomatoes, roasted peppers, aubergines, mushrooms, and chillies preserved in olive oil are found in every Italian pantry and form the backbone of the 'antipasto della casa' served at trattorie across the country. The technique for sottoli is precise: vegetables are first treated to reduce their water content (blanching in vinegar-acidified water, grilling, salting, or sun-drying), then packed tightly into sterilised jars and covered completely with extra-virgin olive oil, ensuring no air pockets. The oil creates an anaerobic environment that prevents mould and bacterial growth, while the initial acid treatment (blanching in vinegar water) lowers the pH to safe levels. Sottaceti are simpler: vegetables (giardiniera—a mixed vegetable pickle—is the most common) are blanched briefly and submerged in a boiling mixture of white wine vinegar, water, sugar, and salt. The vinegar's acidity is the preservative. Both traditions are deeply regional: Puglia's lampascioni (wild onion bulbs) in oil, Piedmont's giardiniera, Liguria's funghi sott'olio, Calabria's peperoncini sott'olio, Sicily's caponata preserved in jars.
Sottoli: blanch/grill vegetables first, then submerge completely in olive oil. Sottaceti: submerge in vinegar/water solution. Vegetables must be treated (blanched in acidified water) before oil preservation. No air pockets—complete submersion. Sterilise jars. Store in cool, dark place.
Always blanch vegetables in a 50:50 vinegar-water mixture before preserving in oil—this is a critical food safety step. Pack vegetables tightly to minimise air. Tap the jar firmly on the counter to release trapped bubbles. Top up with oil after 24 hours (vegetables absorb oil and settle). The preserving oil becomes flavoured and is itself a valuable ingredient for cooking and dressing.
Putting raw, untreated vegetables directly in oil (botulism risk—must acidify first). Leaving air pockets (creates anaerobic pockets where botulism can grow). Using poor-quality oil (it's both preservative and flavour). Not blanching in vinegar-water first for sottoli (essential safety step). Opening and leaving at room temperature for days (refrigerate after opening).
Touring Club Italiano, Regional Italian Cooking; Academia Barilla, Italian Pantry