Harvesting the health benefits of French birch sap in spring

Birch sap harvest season - known as la récolte de la sève de bouleau in French - has come a month early across the country due to mild temperatures. It is set to end today.

For years, producers have harvested the sap, or water, to process and sell. It is prized for its perceived detoxifying properties.

This year, the short season has taken place one month early. Normally it starts in Spring and ends on April 15, but the 2021 season ended today, on March 15 after mild weather in the second half of February caused the sap to build up earlier than normal.

The harvest has notably been good in the Pyrenees, and Yonne in central-eastern France.

Jean-Marc Hochart, producer at le Ferme de Verlin, in Yonne, told news service France 3: “This year we started a bit earlier. We are almost at the end. It started a few days ago because in February we had some significant heat, so the buds came out a little bit earlier.”

The water is harvested - or “tapped” - by making a 3cm-deep hole in the trunk, away from any moss or lichen; and as low as possible, to catch as much water as possible as it rises.

A pipe is then attached at the hole site, and hermetically sealed, so as not to allow the sap to oxidize. The pipes gather the sap drop by drop, which is collected in a vat.

At the end of the season, a little wooden cover is plugged into the hole in the trunk, allowing the tree to repair itself without any long-term damage.

Around 1,000 litres of sap move from the roots to the top of a tree everyday. Producers may collect up to 50 litres per tree per season, but most do a lot less.

Once collected, the water is treated, conditioned, filtered, pasteurised, and then bottled.

Birch water benefits?

Jean-Louis Savignol, a birch water producer in the Pyrenees, claims: “There are many virtues of birch. It is rich in minerals and trace elements; detoxifying for the body, the liver, the pancreas and the kidneys; and for sportsmen and women, it improves performance, reduces tendonitis, allows a faster recovery, and fixes proteins.”

Chantal Lassalle, at the Ferme de Verlin, added: “Birch water gets rid of all the toxins that we have built up over the winter. It has a draining and diuretic effect. It works on the liver, the kidneys, and the bladder. And I've seen some clients' skin quality improve.”

While the benefits of birch water have been claimed for centuries, it is slowly becoming more popular, with more adherents each year. Users are advised to drink a glass every morning for three weeks to benefit the most.

Now, a new clinical trial is being launched to investigate whether it indeed does have all the qualities producers say. Up until now, no significant scientific studies have proven (or not) the benefits of birch water.

In the Pyrenees the 30 or so producers are also working to join in a collective, to share resources, and continue to promote the water.

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