Narrator: These massive barrels will eventually be filled
with thousands of liters of wine.
But it's not just so winemakers can age more at once.
Luxury wine producers making some
of the most expensive wine in the world
say these specific barrels, called foudres,
impact the taste of their product,
which is why they're willing to pay
up to $50,000 for a single barrel.
It's not only the size that impacts the taste.
The real star is the wood,
specifically French oak.
Narrator: French oak is a heavily inspected
and regulated resource,
used only for the most precious projects,
like repairing Notre-Dame Cathedral.
In fact, if the French government thinks a cooperage
didn't bid enough for the wood,
it reserves the right to block the sale.
So do these massive barrels really impact the taste of wine?
And why are foudres so expensive?
While both American oak
and French oak can be used to make a foudre,
French oak is considered far superior,
which explains why it's more than twice the cost.
For one, it has a finer grain,
with rings less than 2 millimeters apart.
The slower the tree grows, the tighter the grain.
France's limestone-based soil
and cooler temperatures contribute to this slow process.
This quality allows for a more gradual
and controlled release of the oak compounds,
or tannins, into the wine.
Tannins create the subtle bitter flavor
and texture you experience in a glass of dry wine
or when you bite into the rind of a fruit.
Dominique Moreau of Foudrerie François
comes from a family of wine connoisseurs,
so he knows what wood makes a good wine.
Narrator: Today he's inspecting French oak wood
from his supplier, Gaudelas.
Narrator: This wood has already been dried for about four years.
Once Dominique signs off, it will be transferred
and stored outside the cooperage for a few more weeks
before it's ready to be used.
Wilfrid is the gatekeeper, choosing which wood will be used
for the base and keeping the most attractive pieces
for the main body of the barrel.
Narrator: In the end, only 20% of any given French oak tree
will be deemed suitable to be part of a foudre.
The discarded pieces will be used elsewhere,
like fueling the fires for the toasting.
The boards Wilfrid has chosen are placed one at a time
in this machine, which cuts and angles the sides
and edges to various specifications
based on the size of the barrel.
This allows the boards
to form a tube when they're arranged vertically.
They're held together with cables to maintain their shape
while the entire barrel is steamed
for several hours under a tarp to soften it.
Narrator: After the heat treatment, the cable is removed,
and the coopers take turns hammering on large metal hoops
to replace them and maintain the barrel's shape.
They may also need to adjust the boards
to make sure they're properly aligned and smooth.
Narrator: The amount of rings depends on the size of the foudre.
Narrator: But why use such a large barrel to age wine?
First, it means the winemakers will need fewer barrels.
But most importantly,
it means the wine touches the surface area
of the barrel less often.
So the flavor the barrel adds to the wine is more subtle.
These large foudres also minimize oxygen levels.
While some oxygen is necessary for aging,
too much can flatten the wine.
Narrator: Foudrerie François makes a number
of different-sized foudres, from 1,000 to 50,000 liters.
It also makes egg or ovoid shapes, which are designed
to help circulate the dead yeast cells
and other sediment during fermentation.
Such large barrels need to be moved with forklifts
and accessed using ladders and scaffolding.
The next step is toasting, in which kilns
are lowered into the open barrels.
They're monitored closely, because the barrel could blister
or blacken at this stage, meaning all the work
to build the massive foudre could go to waste.
Narrator: Toasting brings out more of the tannic flavors,
and customers can specify the level.
Narrator: The bottom pieces are created
by attaching smaller boards with wooden dowels.
Strips of wood are also added in between them
to make sure it's an airtight, waterproof fit.
And a groove is cut along the outside edge
so that it will fit securely
into the bottom and act as a seal.
Narrator: At this point, any accessories are added,
like the tasting tap or special thermometers.
Since Foudrerie François customizes its foudres
for its clients,
each barrel is built to their specifications.
Narrator: Logos of the winery brands are also chiseled into the wood.
The containers are finally packaged
and shipped to their final destination.
Foudrerie François has customers all over the world.
Narrator: Typically only high-end wineries use French oak barrels,
which are more expensive than American oak.
They start at about 8,000 euros for a 1,000-liter foudre.
A standard 225-liter French oak barrel
sells for about 900 euros.
And a similar one made of American oak
is about half the cost, at 470 euros.
This ultimately increases the cost of the wine as well.
If an installation is outside of France,
the price goes up even higher
and could be as much as 45,000 euros.
While the oak flavor will start to fade over time,
the foudres can still be used to ferment for decades.
Narrator: Each barrel from Foudrerie François is also marked
with a small plaque for transparency.
Narrator: Traceability is important,
because quality oak trees are a limited resource.
They take over 120 years to mature, so the person
who planted the seed won't even be alive to see the foudre
or taste the wine.
It's March in the Loire Valley of central France,
and a new batch of logs has just arrived
at the Gaudelas sawmill.
The company specializes in processing
and supplying locally sourced oak
to some of the top cooperages in the country,
including Foudrerie François.
Narrator: There's an initial quality check upon arrival,
one of many in the road to becoming foudre.
Narrator: A worker will measure out the desired length
and make note of any initial knots
or imperfections in the wood,
which would cause a leak in the final barrel.
The logs are sorted
and lifted onto a conveyor, where a machine removes the bark.
Each log is then cut into a pile known as a boule
using vertical cuts in the same direction as the fibers.
Then they're unstacked and reexamined.
The ideal pieces have very straight fibers.
Narrator: Quality tight-grain wood
is a treasured resource for cooperages,
so the Office National des Forets,
or ONF, holds auctions for plots of trees every fall.
In 2022, 44,000 cubic meters
of wood were sold to a variety of cooperages
for a record 15 million euros.
Narrator: The boules are placed outside to be air-dried
for up to four years before they're delivered to a buyer.
Narrator: Drying reduces moisture, which can warp the wood
and helps strengthen it for use in a foudre.
Narrator: Since World War II,
the French government has been carefully managing
their growth and distribution.
It maintains some plots of only the straightest trees
with the finest grains,
regularly clearing out any weak outliers.
The ONF also established a system called "mosaic forest"
to battle the climate crisis.
This involves planting a mixture of species
to nurture the growth of the more valuable oak trees.
These methods seem to be working for now.
France's forests have been growing at a rate
of 85,000 hectares per year, according to the ONF.
But the Ministry of Agriculture released a report in 2023
calling for billions of euros to help combat extreme heat
and drought, which it says could eliminate 30%
of tree species in France by 2050.