From Grapes to Must: What Happens at Winery Receiving

Receiving the Harvest: Where Fruit Becomes Wine

Wine Process Series - Part 2 of 17

There is a point in Part 1, Harvest: A Day in the Controlled Chaos of a Winery, when the vineyard stops being the center of attention and the winery takes over.

The bins come off the tractor or truck, the forklift starts moving, the crush pad fills up, and suddenly every decision becomes immediate.

Up to this point, I have been thinking about ripeness, weather, picking crews, transport, vineyard blocks, and how quickly I can get the fruit out of the field. Now the questions change.

What condition is this fruit actually in?

How warm is it?

How much do I have?

Does it need to move immediately, or can it wait?

Does this fruit go straight to the press, through a destemmer, into a fermenter, into cold storage or onto a sorting table?

This is the bridge between harvest and winemaking.

People often imagine grapes arriving at a winery, and simply disappearing into a machine. They come in one side, juice comes out the other and fermentation begins.

It is rarely that simple.

Receiving is a sequence of decisions, and those decisions change with the grape variety, fruit condition, wine style, temperature, maturity, and the equipment available.

A white, a red, a rosé, and a sparkling base can arrive on the same crush pad within a few hours of each other and leave heading in completely different directions.

That is when harvest stops being only agriculture.

Now I am making wine.

Receiving: The First Triage

The first thing I want to know is what I actually have.

Not what the vineyard sample told me yesterday.

Not what I expected the block to deliver.

What is physically sitting in front of me right now?

Are the clusters intact?

Are berries split?

Is there rot?

Mold?

Insect damage?

Sunburn?

Did it rain before picking?

Are the bins leaking juice because they were overfilled, transported too roughly or left sitting too long?

Does anything smell wrong?

Sometimes the answer is obvious before I touch a berry.

Then comes one of the most important questions at receiving:

What temperature did the fruit arrive at?

Temperature tells me how much flexibility I have.

Once berries begin breaking, juice starts meeting oxygen, native yeast, bacteria, and the grape's own enzymes. The warmer that environment becomes, the faster all of those reactions move.

Cool, healthy fruit gives me options.

Warm fruit takes options away.

If juice is already pooling in the bottom of the bin, I have even less reason to let it sit.

This is where refrigeration earns its place.

If the fruit is healthy and cool, I may be able to hold it briefly while the remaining bins from the block arrive. That allows me to build a sensible press load or organize the next cellar operation rather than rushing simply because the first grapes showed up.

But a cold room is a buffer.

It is not a parking lot.

There is a major difference between deliberately holding fruit cold for a reason and forgetting that three tons of grapes are sitting behind a closed door.

Weighing: More Than a Vineyard Statistic

Every lot gets weighed.

That number matters in the vineyard because it tells me yield per block and allows me to compare what we expected with what actually came off the vines.

But inside the winery, weight becomes a production-planning tool.

For white wine, it tells me roughly how much juice I am likely to produce.

There is no perfect conversion from grape weight to juice volume. Variety changes it. Berry size changes it. Ripeness changes it. Fruit condition changes it. The press and the press program change it.

But as a practical working estimate, many whites commonly end up somewhere around 600 to 700 liters of juice per tonne of grapes.

That is not a law.

It is a planning number.

At harvest, planning numbers matter because I need to know which tank will receive that juice before it exists.

Weight also tells me how close I am to a useful press load.

A destemmer can process fruit continuously and surprisingly quickly.

A press cannot.

A press works in batches.

Load.

Press.

Unload.

Clean.

Start again.

If I start a press cycle every time a few bins arrive, I waste capacity.

If I wait too long, fruit backs up.

That is why the press can set the pace of the entire winery during white-wine harvest.

Ten tons of white grapes and ten tons of red grapes can create completely different days.

The white may be constrained by press capacity and press cycles.

The red may be constrained by fermenter space, sorting capacity, and how quickly the crew can physically move fruit.

For reds, weight immediately raises another question:

How much can I safely put into the fermenter?

I need headspace.

As fermentation starts, carbon dioxide lifts the skins, and the cap rises dramatically.

In many red fermenters, filling somewhere around 75 to 80 percent of total capacity is a useful working range, but there is no universal number.

Tank shape matters.

Variety matters.

Cap-management method matters.

Whole-cluster percentage matters.

How aggressive I intend to be with pump-overs or punch-downs matters.

Overfill a tank, and I lose the space I need to work the cap.

I also increase the odds of spending part of the night cleaning grapes off the cellar floor.

Weighing is not accounting.

It is part of running the cellar.

Sampling: Know What You Actually Harvested

By the time fruit arrives at the winery, I have probably sampled that block several times.

That does not mean I stop sampling.

The fruit on the crush pad is the fruit I am actually about to turn into wine.

That is the sample I care about now.

Brix is usually the first measurement because it gives me an indication of sugar, and potential alcohol.

But Brix by itself tells me very little about whether I actually want to make wine from the fruit.

I also want pH.

Titratable acidity.

Depending on the wine, I may want malic acid.

And I want yeast assimilable nitrogen, YAN, early enough that I can build a sensible nutrition plan before fermentation rather than discovering halfway through that the yeast is starving.

The key word is representative.

I can take three perfect berries off the top of a bin, run them through the lab, and get a wonderfully precise number that describes almost nothing about the tons of grapes underneath.

Sun exposure changes ripening.

Cluster position changes ripening.

Berry size changes concentration.

A block can be remarkably uneven even when the average vineyard sample looked perfectly reasonable.

The laboratory is only as useful as the sample I give it.

Red grapes create another complication.

Must Brix measured at crush can sometimes understate the actual sugar that becomes available once fermentation is underway.

Shriveled and raisined berries hold concentrated sugar. Once they enter the fermenter, they begin rehydrating, and releasing that sugar into the must.

That means I can occasionally see Brix hold or even rise during the first day or two.

If I built my fermentation plan entirely around the crush-pad number, I may suddenly discover that I am making a higher-alcohol wine than I thought.

That changes yeast stress.

It changes nutrition requirements.

It changes how I manage the fermentation.

The laboratory does not replace looking at and tasting the fruit.

It gives me another set of eyes.

Sorting: Deciding What Deserves to Become Wine

Sorting is not about making every cluster look like something from a grocery-store display.

That is not the objective.

The objective is to remove what I do not want entering the wine.

Underripe fruit.

Rot.

Mold.

Badly damaged berries.

Insect-damaged fruit.

Leaves.

Dirt.

Stones.

Pieces of wood.

And everything else that falls into the wonderfully broad winemaking category of MOG, material other than grapes.

Sour rot deserves particular attention.

Sour rot is not simply one organism doing one thing.

It is a disease complex involving damaged berries, yeasts, acetic acid bacteria, and commonly fruit flies such as Drosophila.

The biology works as a group.

Yeasts produce ethanol.

Acetic acid bacteria convert that ethanol into acetic acid.

Fruit flies help move organisms around damaged clusters.

By the time badly affected fruit arrives at the winery, volatile acidity may already be part of the problem.

Fruit that smells like vinegar on the sorting table is not going to become cleaner because I put it into a fermenter.

There is no magic fermentation step that turns bad fruit into good fruit.

And yes, vineyards contain bugs.

Anyone surprised by that probably has not spent much time around agriculture.

Some insects are mostly irrelevant.

Others matter.

Multicolored Asian lady beetles are a good example.

If they are processed with the fruit, they can release methoxypyrazines, including isopropyl methoxypyrazine, producing intensely green, vegetal characters often described as bell pepper, peanut, or green vegetable.

These compounds can be detected at extraordinarily low concentrations, measured in nanograms per liter.

That means relatively low beetle populations can become a genuine sensory problem.

That is not cosmetic sorting.

That is preventing a fault before it reaches the tank.

The best sorting still begins in the vineyard.

A good picking crew leaves poor fruit on the vine.

There is very little logic in paying someone to pick rotten fruit, paying to transport it to the winery, and then paying someone else to throw it away.

At the winery, I may sort whole clusters before destemming.

I may sort berries afterward.

That can be done by hand on a moving table or with optical sorting equipment capable of rejecting berries based on size, shape, color and other parameters.

But sorting can also go too far.

If I chase an imaginary bowl of perfect supermarket grapes, I start throwing away perfectly useful fruit.

A little variation in maturity is not automatically a defect.

The question is much simpler:

Does this belong in the wine I am trying to make?

Destemming, Crushing and Whole Cluster Are Different Decisions

Once I have accepted the fruit, I reach one of the first major stylistic decisions.

Do I remove the stems?

Do I crush the berries?

Do I leave the clusters intact?

People often talk about those things as though they are the same decision.

They are not.

Destemming means separating berries from stems.

Crushing means breaking berries.

Whole-cluster fermentation means leaving at least some clusters intact, and fermenting them with stems attached.

Three different operations.

Three different effects.

Many red wines are destemmed because green stems can contribute aggressive tannin, and herbal or vegetal character.

But properly lignified stems can contribute structure, spice, aromatic lift, and a very different fermentation environment.

That is why some winemakers keep a percentage of whole clusters while others ferment entire tanks without destemming.

Stems can also affect potassium extraction and pH, and they can influence color because stem material can adsorb anthocyanins.

Nothing about the decision is neutral.

I make it with my mouth as much as my eyes.

I chew the stem.

Is it woody?

Lignified?

Or is it still green, wet, and bitter?

I check the seeds as another clue.

Brown, crunchy seeds generally make me more comfortable about extraction.

Green, strongly astringent seeds make me much more cautious.

But seed color is not some magic maturity meter.

Neither brown nor green makes the decision by itself.

I taste.

Destemming also does not automatically mean crushing.

Modern destemmers and crushers allow me to adjust roller gaps or bypass crushing almost entirely.

That matters.

More broken berries mean faster juice release, quicker extraction, and more immediate exposure to oxygen and microorganisms.

More intact berries slow some of that process and may allow a degree of intracellular fermentation inside the berries before they rupture.

So simply saying a wine was "destemmed" tells me far less than many people think it does.

Whites have their own choices.

Some white varieties are destemmed and crushed before pressing.

Others go directly into the press as whole clusters.

Whole clusters form a more open press bed because the stems create natural drainage channels, allowing juice to move through the mass more easily.

That can produce cleaner juice with lower solids and gentler extraction.

This is why the words "whole cluster" always need context.

Whole-cluster pressing for a white wine and whole-cluster fermentation for a red wine are completely different techniques used for completely different reasons.

Rosé adds yet another set of choices.

I can direct-press it much like a white wine.

I can give the fruit a short period of skin contact before pressing.

Or I can use saignée, bleeding juice from a red fermenter after limited skin contact.

Three routes.

Three different wines.

The decisions made here lead directly into the next stage of the process. In Part 3, Pressing: Where Juice Extraction Becomes a Winemaking Decision, we look at what happens when the grapes are pressed and how juice extraction becomes another important winemaking decision.

The First Contact With Oxygen

The moment berries break, juice starts meeting oxygen.

That does not mean oxygen is automatically the enemy.

It means oxygen exposure needs a reason.

When receiving, too much uncontrolled oxygen can brown juice, consume protective compounds, and damage delicate aromatic potential.

That is why speed, cold, and careful handling matter.

Sulfur dioxide can be one tool.

Inert gases can be another.

Dry ice can help in certain operations.

Closed transfers matter.

Equipment setup matters.

But there are also times later in processing when a winemaker may deliberately expose juice to oxygen for a specific technical reason.

That is a different decision.

The important distinction is control.

The real question is not whether oxygen exists.

It is whether I am controlling the exposure or the exposure is controlling me.

This Is Where Harvest Becomes Winemaking

When those grapes arrived, they were still agricultural fruit.

Within a few hours, they may have been weighed, sampled, tasted, sorted, destemmed, crushed, cooled, or sent directly into the press.

Some lots may already be in fermenters.

Some may still be waiting in cold storage.

One tank may contain completely destemmed berries.

Another may contain 30 percent whole clusters.

Another may be headed for a cold soak.

Another may be direct pressed.

Another may be destined for rosé.

All of that can happen from fruit that arrived on the same crush pad.

None of it is particularly glamorous.

Harvest is forklifts.

Sticky floors.

Wet boots.

Hoses everywhere.

Bins arriving before you are ready for them.

Someone looking for a fitting that was in the same place yesterday, and has now apparently vanished from the winery.

And a crew trying to keep several operations moving at once without making mistakes that will follow the wine for the next year.

But these early decisions carry enormous weight.

Because once something enters the wine, removing it becomes much harder than keeping it out in the first place.

Bad fruit is easier to remove on a sorting table than bad flavors are to remove from finished wine.

Excessive oxidation is easier to prevent than to repair.

An unripe stem is easier to discard before fermentation than to argue with six months later.

Receiving is about preserving options.

Keep the fruit healthy.

Keep it moving.

Know what you actually have.

Taste it.

Measure it.

Remove what you do not want.

Handle the berries according to the wine you actually intend to make.

Then move on.

Because the next step is the press.

And the press brings another deceptively simple question:

How hard do you squeeze a grape before you start extracting things you never wanted in the first place?

After Part 3, the process moves into Part 4, Before Fermentation: The Quiet Hours That Shape the Wine, where the focus shifts to what happens after the juice has been extracted and before fermentation begins.

Wine Process Series

1. Harvest: A Day in the Controlled Chaos of a Winery

2. From Grapes to Must: What Happens the Moment Fruit Hits the Winery

3. Pressing: Where Juice Extraction Becomes a Winemaking Decision

4. Before Fermentation: The Quiet Hours That Shape the Wine

5. The Start of Fermentation: When Grape Juice Becomes Wine

6. Fermentation in Full Swing: When Every Sense Goes to Work

7. The Final Third of Fermentation: Where Problems Often Begin

8. Fermentation Is Over. The Wine Is Not Finished.

9. Racking: What Stays, What Goes, and Why

10. Lees: The Material at the Bottom of the Tank Is Not Waste

11. Wine Aging Vessels: Stainless Steel, Concrete, Amphora and Oak

12. Oak Is Not Just Oak

13. The First Months of Maturation: When Doing Less Becomes the Job

14. Blending: When Separate Wines Become the Final Wine

15. Clarification and Stabilization: Making the Wine Ready to Bottle

16. From Cellar to Bottle: The Final Check

17. Bottle Maturation: When Control Changes Form

About the Author

Sébastien Gavillet is COO of Wine Aromas - Le Nez du Vin. A renowned wine and whisky expert, winemaker, and distiller, Sébastien has been working with Le Nez du Vin for over 25 years. He is the author of Discovering and Mastering Single Malt Scotch Whisky and the International Whisky Guide series. He serves as a panel chair and examiner for The Council of Whiskey Masters, shaping global tasting standards and mentoring the next generation of spirits professionals.