Winemaking for WSET: every stage is a choice

Level 3 does not ask you to recite a production sequence. It asks how a producer arrived at a particular style, which means every stage of winemaking has to be held in your head as a decision with consequences rather than a step in a list. This guide sets out those decisions in order, and frames each one the way examiners want to see it.

The contrast that organises everything

White and red winemaking differ in one structural respect, and almost everything else follows from it.

For white wine, the grapes are pressed before fermentation, so the juice is separated from the skins at the outset. Little colour, tannin or skin-derived flavour is extracted, and fermentation is typically run cool to preserve delicate aromatics.

For red wine, fermentation happens on the skins, because colour, tannin and much of the flavour sit in them and require both time and alcohol to extract. Fermentation runs warmer, and pressing comes afterwards.

Say that clearly in an answer and you have already framed the rest correctly.

Before fermentation

Grapes may be destemmed and crushed, or kept as whole bunches, which for reds introduces some stem tannin and can encourage a partly carbonic character. For whites, a period of skin contact before pressing can increase aroma and texture at the cost of some delicacy.

Pressing is gentler for whites, and the fractions matter: free-run juice is the finest, later press fractions are coarser and more phenolic. Must adjustments may be permitted or required depending on the region, chiefly enrichment to raise potential alcohol in cool climates and acidification in warm ones. Which of these is legal where is itself examinable.

Fermentation

Four choices carry most of the marks here:

• Yeast. Cultured yeast gives predictability and a known aromatic profile. Ambient yeast is less predictable and slower but is often credited with greater complexity.
• Temperature. Cooler fermentations, broadly in the low to middle teens up to the low twenties Celsius for whites, retain fruity and floral aromatics. Warmer fermentations for reds, generally in the twenties to around thirty Celsius, favour extraction of colour and tannin.
• Vessel. Stainless steel is inert and preserves primary fruit. Oak contributes flavour and permits slow oxygen ingress. Concrete is inert like steel but offers thermal stability and, in egg form, natural circulation.
• Cap management, for reds only. The skins float to form a cap that must be kept in contact with the juice. Punching down is gentle, pumping over is the workhorse method and adds oxygen, and rack and return is the most extractive. The choice is a direct lever on tannin and colour.

After fermentation

Malolactic conversion transforms sharper malic acid into softer lactic acid, lowering perceived acidity and potentially adding buttery notes. It is standard for nearly all reds, optional for whites, and deliberately blocked for aromatic whites where crispness is the point. Being able to say why a producer blocked it is worth more than knowing that it exists.

Lees ageing leaves the wine on its dead yeast cells, adding bready, biscuit character and texture, with stirring, or bâtonnage, increasing the effect. Oak maturation is governed by three variables that should always appear together in an answer: whether the oak is new or old, the size of the vessel, and the length of time. Read it alongside oak influence on wine.

Blending may combine varieties, vineyards, vintages or vessels, and is a quality tool rather than a compromise. Fining and filtration clarify and stabilise, at some potential cost to texture, and cold stabilisation prevents harmless tartrate crystals forming in bottle.

Rosé, briefly

Three methods appear on the syllabus. Direct pressing treats black grapes almost like whites and gives the palest styles. Short maceration leaves juice on skins for a limited period before drawing it off, giving more colour and structure. Blending red and white wine is generally not permitted for still rosé under EU rules, though it is allowed for Champagne, which makes it a favourite exam detail.

Where to go from here

Winemaking connects directly to the two specialised processes on the syllabus, so read it with sparkling wine production methods and fortified wine production. Then check how the topic is examined in the Level 3 guide.

FAQ: winemaking questions

What is the main difference between red and white winemaking? White grapes are pressed before fermentation, so there is little skin extraction. Red grapes are fermented on their skins to extract colour, tannin and flavour.

What does malolactic conversion do? It converts sharper malic acid into softer lactic acid, reducing perceived acidity and potentially adding buttery character. It is usually blocked for aromatic whites.

Why manage the cap during red fermentation? The skins float and must be kept in contact with the juice. Punching down, pumping over and rack and return give increasing levels of extraction.

What does lees ageing add? Bready, biscuit-like character and a fuller texture, increased by stirring the lees.

How is rosé made? Chiefly by direct pressing or by a short maceration on skins. Blending red and white is generally not permitted for still rosé in the EU, though it is allowed for Champagne.