The Journey of a Cork: Part One

It’s mere millimeters in diameter and only a few centimeters long, but the small, springy cylinders that stopper wine can be the difference between a delicious bottle and a spoiled one. Cork’s role is a bit daunting: it’s responsible for preventing a bottle of wine from being exposed to too much or too little oxygen as it ages. Cork is a truly one-of-a-kind substance, requiring as much care and quality assurance as the wine does — and last month, Assistant Winemaker Jesse Fox had the privilege of witnessing this process firsthand in the cork forests of Portugal, home to 50% of the world’s harvested cork trees.

This trip was made possible by Portocork, the primary provider of the corks that go into each bottle of Ram’s Gate wine. In the company of a few fellow winemakers, Jesse began his trip arriving in beautiful Lisbon…

Sunrise in Lisbon Portugal

…before heading to a cork forest in Palmela, Porgutal, about an hour away.

A Cork Oak Forest near Lisbon, Portugal

Act I: The Harvest

“The energy of a cork harvest reminds me of the grape harvest,” Jesse describes. “A group of highly skilled workers specialize in removing the inch or so of bark from the trees, working with incredible speed and precision.”

Cork Being Harvested near Lisbon, Portugal

A close-up of a partially harvested cork tree near Lisbon, Portugal

In this particular forest, you’ll notice only half of the tree is being harvested. This is because cork bark takes about nine years to grow between harvests; harvesting half of a tree allows that tree to be harvested on a four- or five-year cycle. However, Portocork is in the process of transitioning to harvest an entire tree at once, which will take place in the next few years.

Assistant Winemaker Jesse Fox Harvesting Cork
Jesse Fox with a piece of freshly harvested cork bark.

Just as terroir is a crucial component in growing wine grapes, the same factors impact cork trees, which thrive in well-drained, sandy soils and the dry Mediterranean climate found in southern Portugal. Cork trees need very little water, are resistant to fire, and their lifespan can exceed two hundred years.

Cork Trees are Grown in Sandy Soils in Portugal
Sandy soils in which the cork trees grow

After removing the cork bark from the tree…

…the bark is placed onto a flatbed to be transported to the cork-making facilities.

Freshly harvested cork bark ready to be transported

Act II: Drying

Upon arriving at the cork-making facilities, the bark is first dried out for at least a year.

Cork bark arriving on the cork
Cork immediately upon arrival at the cork facility
Cork drying outside the cork facility
Cork drying outside the cork facility

“In recent years, the quality assurance of this stage in the process has improved dramatically,” Jesse says. “By laying the bark on raised chocks and covering them, the bark is protected from the elements and has a far less risk of mold or mildew, factors that can contribute to TCA or cork taint.”

Act III: Soaking 

Next, the slabs of cork soak in large vats of water, heating and re-hydrating the cork to remove any volatile compounds, particularly TCA, otherwise known as “cork taint.” As TCA is a volatile compound, it evaporates at high temperatures.

Cork Soaking Cork Soaking

This is the first of 20+ stages of quality control before the cork comes to Ram’s Gate Winery – but more on that in Part 2 next week.

Until then, cheers!
Ram’s Gate Winery

3 thoughts on “The Journey of a Cork: Part One”

  1. This piece is absolutely the best one I have seen on this blog! Thanks so much for sharing the process! Very well done – great photo illustrations – I learned something and had fun in the process!
    Kudos to the author and to Ram’s Gate for understanding how to cultivate customers as well as grapes.

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