Aioli — The Mortar and the Patience

True aioli is garlic pounded to a smooth, sticky paste in a marble or stone mortar, then emulsified with olive oil added drop by drop — no egg yolk, no lemon at the outset, nothing but garlic, oil, salt, and the slow rotation of the pestle. This is the Provençal original, the sauce that predates mayonnaise by centuries, and the technique where the dish lives or dies is in the first thirty seconds: if the garlic paste is not perfectly smooth and cohesive before the first drop of oil falls, the emulsion will never form. Quality hierarchy: 1) Mortar-pounded aioli using Violet de Cadours or fresh hardneck garlic, Provençal extra-virgin olive oil, and nothing else — intensely aromatic, thick enough to hold a pestle upright, with a slow burn from raw allicin and a fruity olive finish. 2) Mortar aioli with a single egg yolk added for stability — slightly richer, more forgiving, still handmade. 3) Food-processor aioli — functional, but the blade heats the garlic and ruptures cells differently, producing a sharper, more acrid flavour that lacks the rounded sweetness of stone-ground paste. The emulsion science is the same as mayonnaise but more demanding. In egg-based emulsions, lecithin from the yolk acts as a powerful surfactant, stabilising oil droplets effortlessly. Without egg, the emulsifier is a combination of garlic's cellular mucilage and the mechanical energy of the pestle. The mortar's rough surface shears garlic cells, releasing sticky polysaccharides that coat oil droplets and prevent coalescence. This is why the mortar must be stone or ceramic — smooth stainless steel bowls cannot generate the necessary friction. The garlic matters at species level. Violet de Cadours, a French hardneck variety, offers moderate heat, deep sweetness, and a purple-streaked clove that pounds to an exceptionally sticky paste. Spanish Roja, another hardneck, provides earthier, more complex notes. Avoid Chinese softneck garlic — it is often harsh, overly sulphurous, and its lower sugar content produces a paste that tastes of nothing but burn. Fresh season garlic (late spring, early summer) is ideal: high moisture, mild heat, no green germ. If the clove has a green sprout at its centre, remove it — that germ is disproportionately bitter and will dominate the sauce. Begin with 4-6 cloves (roughly 20g) peeled and sprinkled with coarse sea salt — the salt acts as an abrasive, accelerating the breakdown. Pound in a circular motion, scraping the sides of the mortar, until you have an utterly smooth, wet paste with no visible fibre — 3 to 5 minutes of committed work. Now add oil: the first 50ml must go in drop by drop, with constant circular grinding. You will feel the resistance change as the emulsion forms — the pestle drags, the paste stiffens, the colour shifts from translucent grey-green to opaque ivory. Once the emulsion catches, you can increase the oil flow to a thin stream. Total oil: 200-250ml for 20g of garlic. If the sauce becomes too thick, a few drops of warm water (not lemon, not yet) will loosen it without breaking the emulsion. Season with lemon juice at the end, to taste. Sensory tests: the finished aioli should hold a firm peak on the pestle. It should smell intensely of garlic with a clean olive-oil backdrop — no metallic or acrid notes. The colour should be pale ivory to light gold. Taste should deliver garlic heat that builds slowly, followed by fruity oil sweetness, then a long peppery finish from the olive oil's polyphenols.