Destemming and crushing in winemaking

Quick answer

After grapes arrive at a winery, the fruit may be sorted, destemmed, crushed or handled as whole bunches before the next stage of winemaking.

Destemming separates berries from their stems, also called stalks. It may remove all the stems, some of them or none. Crushing breaks the grape berries so that juice comes into contact with the skins, pulp and seeds. The result may be called must: a grape mixture that can contain juice, skins, seeds, pulp and remaining stems.

A winery may use a crusher-destemmer to perform both jobs, but the settings and handling can vary. Some fruit may be destemmed with much of its berry structure preserved. Some may be crushed while retaining stems. Other fruit may remain as whole bunches.

These decisions shape the physical conditions entering fermentation or pressing. They can influence juice release, grape solids, tannin extraction, colour extraction and oxygen exposure. They do not guarantee a particular flavour or quality outcome, because variety, fruit condition, stem maturity and later winemaking choices also matter.

What happens to the grapes?

A simplified sequence is:

1. Grapes are harvested and brought to the winery.
2. The fruit may be inspected or sorted.
3. Stems may be removed, berries may be broken, or whole bunches may be retained.
4. The result becomes must or juice containing varying amounts of grape solids.
5. The fruit or juice proceeds to the next operation, such as pressing, fermentation or another form of extraction.

This is a map rather than a rulebook. Destemming can happen before crushing, both can happen in the same machine, or neither may happen before whole-bunch handling.

Whole bunch, whole berry and berry integrity

These terms are easy to confuse.

A whole bunch still has its stems attached. Whole-bunch handling therefore retains stems and intact berries at least initially.

A whole berry has not been broken, but it may already have been separated from its stems. Whole-bunch and whole-berry processing are not interchangeable.

Berry integrity describes how intact the berries remain. Lightly handled fruit may contain many whole berries alongside some broken ones. More intensive crushing produces more juice and contact between liquid and solids.

Grape solids include skins, seeds, pulp and any remaining stems. In a white wine, a winemaker may separate juice from many of these solids before fermentation. In a red wine, skins commonly remain involved in fermentation, although processing choices vary.

Why do stems matter?

Stems add physical structure to a mass of grapes. They can affect how fruit drains, moves and sits in a fermenter. They can also contribute tannin and other compounds.

According to Australian Wine Research Institute guidance, stem effects depend on factors including variety, season and how mature or lignified the stems are. Retained stems may contribute structure or savoury character, but less mature stems can also contribute herbal, grassy or overly astringent impressions.

That is why “more stems” is not automatically better or worse. It is a decision that interacts with the fruit and the rest of the winemaking process. Whole-bunch fermentation explores retained stems in more detail.

Why does crushing matter?

Breaking berries releases juice and increases contact between juice and grape solids. This can affect:

• how much juice is available;
• the amount of skins, seeds and pulp in the must;
• phenolic and colour extraction;
• the amount of suspended solids;
• later drainage, clarification and pressing;
• the juice’s exposure to oxygen.

More intensive crushing can produce more broken tissue and solids. Australian Wine Research Institute material identifies possible consequences including excessive lees, tannic astringency, aeration and drainage or equipment-handling problems. These are possible effects, not inevitable results.

Crushing also does not mean every berry is reduced to pulp. A batch described as crushed may still contain many intact berries.

How processing differs by wine type

Red wine

Red grapes may be destemmed and crushed before fermentation with skins present. A winemaker may also retain some stems, include whole bunches or preserve more whole berries. These choices affect the material entering fermentation and the way extraction is managed.

White wine

White grapes may be pressed as whole bunches, or destemmed and crushed before pressing. Some wines use limited skin contact or retain more grape solids in the juice. Others separate the juice from solids more thoroughly. There is no universal white-wine pathway.

Rosé

Rosé can use a range of red- and white-wine approaches. Grapes may be crushed or destemmed, pressed directly or allowed limited contact with skins. The method depends on the intended wine and winery practice.

Australian research and technical guidance show this variety of approaches rather than one national standard. Wine Australia also uses must broadly for juice from crushed berries that may still contain skins, seeds, pulp, stems and leaves.

What destemming and crushing do not tell you

Words such as “destemmed”, “crushed” or “whole bunch” describe processing choices, not a guaranteed taste. They do not tell you the exact equipment, degree of berry breakage, stem proportion or final wine style.

Also, whole-bunch handling is not the same as carbonic maceration. Carbonic maceration is a separate fermentation method involving intact bunches in a closed, carbon-dioxide-filled environment without free juice. For the wider sequence, see how wine is made.

The useful takeaway is simple: destemming controls how many stems remain, while crushing controls how much the berries are broken. Winemakers can use either operation as a separate tool or combine them, depending on the fruit and the wine they are trying to make.

Frequently asked questions

Does destemming remove every stem?

Not necessarily. Destemming means stems are removed as part of processing, but some stem material may remain, especially where fruit is only partly destemmed or mixed with whole bunches.

Are destemming and crushing always done together?

No. They may be performed together in a crusher-destemmer, separately, partially or not at all.

Does crushing make red wine darker?

It can influence contact between juice, skins and seeds, which may affect colour extraction. It does not guarantee a darker wine; variety, fruit condition and fermentation management also matter.

Is whole-bunch wine the same as whole-berry wine?

No. Whole bunches retain stems. Whole berries may have been separated from stems but remain intact.

What happens after crushing?

The fruit may proceed to pressing, alcoholic fermentation or another operation, depending on the wine and the chosen process.