Tomate concassée is listed in Escoffier's guides as standard mise en place. The name comes from the French concasser, meaning to crush or break up. The technique exists because fresh whole tomatoes carry too much water (seeds and surrounding gel), too much bitterness (in the seed gel specifically), and a skin that detaches unappetisingly from the flesh during cooking. Concassé removes all three sources of disruption in a single preparation sequence.
The three-stage preparation of fresh tomatoes — blanching to remove the skin, seeding to remove excess liquid and bitter seed gel, then dicing to a precise, regular size. Concassé is not merely a cut; it is a transformation. A whole tomato carries water, bitterness, and structural unevenness that concassé eliminates. What remains is clean, dense, flavour-concentrated tomato flesh — ready for sauces, garnishes, or as a finished element that maintains its integrity on the plate.
Removing seeds and skin is an act of deliberate flavour concentration. The seeds' surrounding gel contains the highest citric acid concentration in the fruit (bitterness and wateriness); the skin contributes a slight bitterness and a chewy texture that detracts from refined preparations. Removing both produces flesh that is sweeter, denser, and more clearly flavoured. As Segnit notes, tomato's glutamate content — making it a natural umami source — is highest in the flesh closest to the seed cavity; this is why seeding must be done precisely and not wastefully, preserving the inner wall of flesh that carries the most glutamate-rich material. Tomato concassé with basil and olive oil works through multiple mechanisms simultaneously: the basil's linalool and eugenol compounds are fat-soluble and bond with olive oil; the tomato's water-soluble acids provide counterpoint; and the combination produces a flavour larger than its components because fat carries and extends the aromatic compounds across the full tasting experience.
**Ingredient precision:** - Tomatoes: vine-ripened, at room temperature — cold tomatoes have less pronounced flavour and the skin adheres more firmly, requiring longer blanching that risks cooking the flesh. For concassé intended for uncooked applications (salads, crudo): summer tomatoes at peak ripeness. For concassé intended for cooked sauces: Roma (plum) tomatoes have lower water content, denser flesh, and fewer seeds — they maintain their texture through heat better than round salad tomatoes. - Size: all tomatoes in the batch should be of similar size and ripeness — uneven ripeness means uneven blanching times, which means some tomatoes are over-blanched while others are insufficiently peeled. 1. Score a shallow X in the base (not the stem end) of each tomato — cut through the skin only, not into the flesh. This is the entry point for the peeling. 2. Blanch in vigorously boiling, unsalted water for 10–20 seconds for a ripe tomato; up to 30 seconds for a firmer one. The skin at the X will visibly begin to curl back — this is the visual signal to remove the tomato. 3. Transfer immediately to ice water — the shock stops cooking and firms the flesh for clean cutting. 4. Peel from the X outward — the skin lifts in four sections and should come away in one motion per section without resistance. 5. Quarter the tomato. Holding each quarter over a bowl, use the tip of the finger or a small spoon to sweep the seeds and surrounding gel cleanly from the flesh — a single motion, not multiple passes. 6. Cut the cleaned flesh into the desired dice — brunoise (3mm) for sauce work, medium (5mm) for salads and garnishes, large (8mm) for braise components. Decisive moment: The blanching time — specifically, pulling the tomatoes from the boiling water at the first sign of skin curling rather than waiting until the skin peels away entirely. A tomato left 10 seconds too long in boiling water has its surface proteins denatured — the outer flesh becomes soft and translucent, losing its structural integrity. This compromised flesh will fall apart during dicing and produce a watery, uneven concassé rather than clean, firm cubes. Pull early. The skin peels from a slightly under-blanched tomato with a gentle assist; the skin of a correctly blanched tomato peels itself. Sensory tests: **Sight — the blanching signal:** Watch the X from the moment the tomato enters the water. The skin at the four quadrants of the X begins to curl outward — folding back from the cut like a flower opening. The moment all four quadrants show visible curl, the tomato is ready. Do not wait for the skin to detach completely — that is overblanching. **Feel — peeling the cooled tomato:** The skin of a correctly blanched, ice-shocked tomato lifts easily under a thumbnail at the X — it slides off the flesh without resistance, leaving a clean, firm surface beneath. If the skin resists, the blanching was slightly insufficient — a gentle upward peel from the X will still remove it. If the skin comes away with a layer of softened flesh attached, the tomato was overblanched. **Sight — the seeded flesh:** After seeding: the inside of the tomato flesh should be smooth, clean, and slightly translucent — none of the gel or seed material remaining in the cavity. The flesh itself should be firm and brightly coloured. Any remaining gel — visible as a slightly thicker, slightly darker area at the inner wall — must be removed. This gel carries the seed's bitter compounds. **Sight — the finished concassé:** Regular, clean cubes with consistent colour — bright red throughout, no pale areas (from the interior walls), no seed fragments. The cut surfaces should be clean rather than ragged — a sign the tomato was firm enough to hold its structure during dicing.
- The seeds and gel are not wasted — press them through a fine sieve and collect the tomato water. This is naturally thickened, deeply flavoured, and can be reduced for sauces or used raw for consommé - Very ripe summer tomatoes may peel without blanching at all — a serrated tomato peeler applied directly to the skin removes it in one pass. Test a single tomato before committing the batch - Concassé stored covered with a light film of olive oil and a pinch of salt for up to 2 hours actually improves — the salt draws out residual water and the flavour concentrates
— **Overblanched — soft, mushy flesh:** The tomato was in the boiling water too long, or was not ice-shocked quickly enough. The outer flesh has cooked. The concassé will fall apart rather than hold its cube shape. — **Seed gel remaining:** The seeding was incomplete or rushed — the gel was pushed aside rather than removed. This gel releases bitterness and excessive water into any preparation it contacts. — **Watery concassé pooling on the plate:** Normal if just cut — allow to drain on a cloth for 5 minutes before service. For sauce applications, this liquid is not waste — press it through a sieve and use it as tomato water in the sauce. — **Uneven dice:** Inconsistent knife technique. In sauce applications this matters less; in composed salads and refined garnish work it signals a lack of care that reads on the plate.
Jacques Pépin's Complete Techniques