Pressing wine grapes: what it does and why it matters

Quick answer: what is pressing?

Pressing wine grapes means applying controlled pressure to grape bunches, crushed grapes or fermenting grape solids so that liquid separates from the solid material.

The liquid may be grape juice, called must before fermentation, or wine after red grapes have fermented with their skins. The solids left behind are mainly skins, seeds, pulp and sometimes stems; together, this material is often called pomace.

Pressing is a distinct winemaking operation. It is not the same as crushing, which breaks grape berries, or destemming, which removes stems. It is also different from maceration, the period when juice or wine remains in contact with grape solids, and fermentation, when yeast converts grape sugars into alcohol and other compounds.

The timing of pressing helps explain differences between wine styles. White grapes are commonly pressed before fermentation, while red grapes are commonly fermented with their skins before being pressed. Rosé sits between these broad patterns: grapes may be pressed directly, or allowed limited skin contact before pressing.

Pressing is therefore not just a way to extract more liquid. It is a decision that can influence solids, phenolics, tannin, colour, oxygen exposure and the eventual texture and style of a wine.

How pressing fits into winemaking

The exact sequence varies, but the basic idea is straightforward:

1. Grapes arrive and are assessed for their condition, variety and intended wine style.
2. They are loaded into a press as whole bunches, crushed or destemmed grapes, or red fermenting grape solids.
3. Some juice may drain before substantial pressure is applied.
4. Pressure is increased in stages, with juice collected during different parts of the cycle.
5. The remaining skins, seeds, pulp and stems form the press cake or pomace.
6. The resulting juice or wine may be settled, fermented, matured, blended or held separately.

This is a conceptual overview, not a cellar recipe. There is no single pressure, timing or yield that suits every grape or wine.

For a broader overview of the production sequence, see how wine is made. For the earlier operations that prepare grapes for some presses, see destemming and crushing.

When are grapes pressed?

White wine

White grapes are commonly pressed before fermentation. Separating the juice from skins and seeds early helps the winemaker manage colour, suspended solids and phenolic extraction.

Some white grapes are pressed as whole bunches; others are crushed or destemmed first. Oxygen exposure is also important. It may contribute to browning or changes in aroma and composition, although some winemakers deliberately use oxidative handling for particular purposes. Oxygen is a variable to manage, not simply an enemy to eliminate.

Rosé wine

Rosé can be made by pressing red grapes directly, or by allowing the juice limited contact with red skins before pressing. That contact can contribute colour and phenolic material, so pressing timing becomes part of the style decision.

These are common approaches rather than fixed rules. Variety, fruit condition and the intended colour and texture all matter.

Red wine

Red grapes are commonly crushed and fermented with their skins, seeds and sometimes stems. Pressing then separates the wine from the pomace, usually during or after fermentation or maceration.

Because pressing can release additional material from skins and seeds, it may contribute to the wine’s tannin, colour and texture. Pressing earlier or later changes the overall extraction pathway, but it does not determine the final wine on its own.

For the role of fermentation in this sequence, see what is fermentation?.

Free-run juice and press fractions

You may hear Australian winemakers talk about free-run juice, soft pressings and hard pressings.

Free-run juice is liquid that drains from grapes or crushed grape material with little or no applied pressure. Press juice, or pressings, is recovered through mechanical pressure. In practice, the boundaries between these terms are not identical at every winery. Some wineries separate several stages; others group them more broadly.

Juice collected at different stages can differ in suspended solids, phenolics, acidity, colour and aroma compounds. Later or harder pressings may contain more material extracted from skins and seeds, but that does not make them automatically inferior. A winery may keep fractions separate, use some in a blend, or exclude some from a particular wine depending on its composition and intended style.

The useful lesson is that “free-run” is not a universal synonym for “best”, and “pressings” is not a universal synonym for “poor quality”.

What does pressure change?

Pressing involves a balance between recovering liquid and controlling what comes with it.

More intensive pressure or mechanical action can increase juice recovery, but may also extract more phenolic compounds from skins, seeds and stems. Depending on the fruit and the wine, that can contribute useful structure—or more bitterness, astringency, colour or suspended solids than the winemaker wants.

Harder pressing can also produce juice with greater turbidity. This may affect later clarification, fermentation and texture. Oxygen can enter during pressing and while juice drains or is transferred, potentially influencing browning, aroma, colour and mouthfeel.

These effects are tendencies, not guarantees. Variety, maturity, fruit condition, press design, pressure programme and subsequent handling all influence the result. The same pressing choice can be useful in one wine and unsuitable in another.

Whole-bunch pressing

Whole-bunch, or whole-cluster, pressing means pressing intact bunches rather than first removing the stems and fully crushing the berries.

Stems can create drainage channels through the mass of skins and seeds, helping juice flow without relying entirely on aggressive mechanical action. Whole-bunch pressing is particularly relevant to some white and sparkling-wine production, where limiting excessive phenolic extraction can be important.

Whole-bunch pressing is not the same as whole-bunch fermentation:

• Whole-bunch pressing: intact bunches are pressed to obtain juice.
• Whole-bunch fermentation: intact bunches remain in contact with fermenting juice or wine.

The two methods may be used together or separately. Retaining stems does not guarantee a particular aroma, freshness or texture; the outcome depends on the fruit and the complete winemaking approach. You can learn more about the distinction in whole-bunch fermentation.

Common types of wine press

A pneumatic or membrane press uses an inflatable membrane to compress grapes against a perforated cage. Pressure can be applied through programmed cycles of compression and release.

A basket press encloses grapes or fermented pomace in a basket and compresses them with a plate or similar mechanism.

Other systems use more continuous movement or mechanical compression. For a beginner, the key point is not that one design is always best. Press design affects how grapes move, drain, break up and contact oxygen, which can in turn influence the juice or wine.

Australian wineries use a range of presses and production approaches across still, sparkling and fortified wine. There is no single national pressing recipe.

What pressing can tell you about wine

Pressing is one of several decisions that shape a wine. It can affect the amount of liquid recovered and the balance of solids, phenolics, colour and oxygen exposure. It may therefore contribute to differences in texture, bitterness, tannin, aroma and overall style.

But pressing does not work alone. Grape variety, climate, fruit condition, fermentation, skin contact, maturation and blending also matter. If a wine tastes more textured or tannic, pressing may be part of the explanation—but it is rarely the whole story.

The most useful way to think about pressing is as a controlled compromise: recover the juice or wine that is useful while managing the compounds and oxygen that come with it.

Frequently asked questions

Is pressed juice worse than free-run juice?

No. They are different fractions, and their composition can vary. A winery may prefer one fraction for a particular wine, blend them, or keep them separate. Neither is automatically superior.

Are white grapes always pressed before fermentation?

No, although pressing before fermentation is common. Skin-contact white wines and other production methods can follow different pathways.

Are red grapes always pressed after fermentation?

No. Pressing commonly occurs during or after fermentation or maceration, but timing varies with wine style, fruit and winery practice.

Does pressing make wine tannic?

It can influence tannin and other phenolic extraction, particularly when pressure brings more material from skins, seeds or stems into the liquid. The final effect depends on the whole production process.

Is whole-bunch pressing the same as whole-bunch fermentation?

No. Whole-bunch pressing is a method of extracting juice from intact bunches. Whole-bunch fermentation leaves those bunches in contact with fermenting juice or wine.

Why might a winery separate press fractions?

Different fractions can have different solids, phenolics, colour, aroma and sensory character. Keeping them separate gives the winemaker more control over later blending and wine style.