Don’t spit out the seeds

Before the shears come the teeth. Each year, as harvest nears, the teams at Domaines Barons de Rothschild Lafite pace the rows. They taste the berries, chew the skins and crack the seeds between their molars. It’s not (only) a guilty pleasure. It’s a science.

The decision to harvest lives inside the fruit. In the skin, the texture, the colour, the cling of the flesh, the snap of the seed. Here there’s no guesswork: the science that decides the harvest is taste.

Harvest in the skin, and beyond.

Skin, pulp, seed: the grape is a three-body problem.

• The pulp, immediate and generous, delivers sugar and acidity. Easy to analyse, but deceptive: sweet grapes aren’t always ready.
• The skin, home to tannins and anthocyanins (colour), must be chewed to judge its toughness, thickness and bitterness.
• The seed, its maturity revealed by colour, crunch and that nutty taste when it’s ready.

The trouble is, these three layers never ripen at the same pace. Winemakers watch for four maturities: technological (sugar/acidity), phenolic (tannins, anthocyanins), aromatic (flavour profile), textural (skin consistency).

Finding the balance is craftsmanship. Among themselves, winemakers call it the côte mal taillée, literally, ‘the badly cut edge’: a rough compromise, the elusive point where skins, pulp and seeds meet in imperfect balance. It’s all about catching the grape at the right moment, neither too soon nor too late.

Did you know?

A ripe seed crunches like a hazelnut. A green seed squeaks under the tooth.

The science behind the bite

Of course, no one harvests on instinct alone. Every week, samples of 200 to 450 berries per plot are analysed in the lab: sugar levels, acidity, tannins, anthocyanins, skin texture measured by penetration tests. And sometimes, to understand what’s happening under the skin, you go all the way down to the microscope.

Under the skin

When viewed through an electron microscope, the skin reveals its secrets: folded layers of natural wax, cell walls of varying thickness, deposits of tannins building up inside the cells. In this intimate architecture lies the grape’s ability to release its tannins.

Lab analysis helps prioritise which plots to harvest first, but no one makes the final call without chewing grapes in the vineyard. Berry tasting remains one of the last purely sensory skills in the hyper-analytical world of wine—a ritual as physical as it is intellectual, where every mouth trains, year after year, to catch the tiny signals the fruit chooses to reveal.

Ripening into senescence

Out in the field, several people usually walk the rows: estate directors, technical managers, R&D team members. Everyone has their own method. Some taste several berries at once to sense the overall balance, others dissect a single one from skin to seed.

The decision is never made on the first try. They return, taste again, discuss. Too green, too acidic, not enough softness? Then they wait. Until the vine begins its retreat, no longer actively feeding the berry.

To ripen is to begin dying. This is senescence, the onset of the fruit’s cellular death.

Left to itself, the berry keeps ripening, releasing what it contains most intensely: tannins, anthocyanins, aromas…

And it’s in this state of daily transformation that the elusive côte mal taillée appears. A point of imbalance that, paradoxically, defines the balance of the vintage to come.

At L’Évangile, the focus is on preserving the freshness of Merlot, while steering clear of jammy aromas.

At Lafite, the goal is to move beyond primary varietal notes to capture the subtler expression of fresh fruit in Cabernet Sauvignon.

For R de Rieussec, Sauvignon is picked early to preserve the brightness of thiols — passion fruit, mango, grapefruit — while Sémillon is left longer on the vine to reveal its terpene-driven aromas: peach, white flowers, jasmine, acacia…

And at Vina Los Vascos, once again, it all comes down to the fruit. Ripeness is read directly on the palate. When the pyrazine softens just enough, when pepper makes way for blackberry and black cherry — that’s the moment.

In the end, this sensory quest is the same for every winemaker, and comes down to a single question: how far can the fruit go before it’s picked? What will be its final burst of brilliance?

So if ever you spot someone in the vines, chewing grapes and spitting out seeds with a smile…you’ll know the time for harvest is near.