🍷 Maceration

Maceration means leaving solid parts to soak in a liquid so that the liquid takes on their colour, taste and aroma. In winemaking, the juice stays in contact with the grape skins, pulp and seeds; in spirit drinks, fruit, herbs or nuts are steeped in alcohol. ²⁸

What the OIV says. The International Organisation of Vine and Wine defines maceration as leaving the solid and liquid parts of harvested grapes in contact for a shorter or longer time, before, during or after fermentation. Its aim is to dissolve substances held in the grapes, above all phenolic compounds, aromas and the precursors of aromas. ² The OIV code admits several ways to do it: classic fermentation on the skins, carbonic maceration, maceration after heating the grapes, cold maceration before fermentation, warm maceration at the end and maceration of raisined grapes in wine. ¹²

Where red colour comes from. Most of the colour of a young red wine comes from anthocyanins, pigments that originate in the grapes. Researchers note that a whole series of winemaking practices has been developed to extract more of these pigments and to keep their colour stable as the wine ages. ⁵ Such pigments, together with other phenolic compounds, are exactly what maceration is meant to dissolve. ²

Tannins and time. A study of Cabernet Sauvignon shows how much the length matters. Tannins from the skins came out quickly and reached their maximum at the first sampling, while large tannin molecules from the seeds kept coming out for up to 20 days. In industrial tanks, tannins rose for about nine days of maceration, until the wine reached 12.7% alcohol, and then hardly changed. Longer maceration made the wine more astringent and bitter, mainly because of seed tannins. ⁶

Cold maceration before fermentation. For red wines the OIV describes cold prefermentative maceration: destemmed or crushed grapes are kept cool, at a temperature and for a time chosen for the goal, before fermentation starts. The aim is to release compounds from the skins, make aroma and taste more complex and improve the colour. The OIV asks winemakers to check the health and ripeness of the grapes first, guard against oxidation, keep hygiene and temperature under control and choose the length by grape and wine style. ³

Carbonic maceration. Here whole grapes spend a few days in a closed tank filled with carbon dioxide, which comes from outside, from the grapes' own breathing and partial fermentation, or from both. A vent keeps the pressure no higher than atmospheric. Afterwards the grapes are crushed and pressed, and the juice ferments without the solids. The result, according to the OIV, is a red or rosé wine that is softer, less acidic and fresher, with clearer varietal aromas. ⁷

White wine with maceration. White wine is usually made from juice without skins, but the OIV also defines white wine with maceration: only white grape varieties, fermented in prolonged contact with the pomace, meaning skins, pulp, seeds and sometimes stems. This contact must last at least one month. Such a wine can have an orange-amber colour and a tannic taste. ⁴

Maceration in spirits. EU rules on spirit drinks name maceration as one of the ways to flavour a drink, alongside infusion, distillation and simply adding flavourings. Some categories are built on it: fruit spirits “obtained by maceration and distillation” need at least 37.5% alcohol and no more than 18 g of sugar per litre, and that wording must appear on the label; sloe gin is made by macerating sloes in gin and has at least 25%; nocino is a liqueur flavoured mainly with macerated green walnuts. ⁸

Why it matters to you. If a label promises long maceration, expect a wine with more tannin, astringency and bitterness. ⁶ The words “obtained by maceration and distillation” on a fruit spirit tell you exactly how it was made, and a white wine with maceration has spent at least a month on its skins. ⁸⁴ Whatever the method, the WHO stresses that there is no safe level of alcohol consumption. ⁹