By RANDY SHORE
A new strain of wine yeast developed at the University of B.C. helps reduce amines, chemicals in red wine and Chardonnay that produce off-flavours and trigger headaches, hypertension and migraines in many people.
Food biotechnologist Hennie van Vuuren spent eight years in research and another seven years to test his genetically modified yeast, dedicating much of his life’s work as a scientist to the project.
About 30 per cent of the people in the world are sensitive to biogenic amines like histamines,” said van Vuuren. “The reason I did this is that I myself get severe headaches if I drink wines with these bioamines in them.”
Health Canada, Environment Canada and the U.S. Food and Drug Administration have approved Malolactic yeast, known by the trade name ML01, for commercial use. Another major wine-producing nation, South Africa, has also declared ML01 safe and van Vuuren is seeking approvals from European authorities.
Production and sale of the yeast is licensed to the Lesaffre Yeast Corp., which pays a royalty to UBC.
“This is the first organism that has been improved [through genetic engineering] where consumers get the benefit and not the corporate producers,” van Vuuren said.
The modified yeast doesn’t introduce any genetic material to wine that wouldn’t have been present anyway in the bacteria used for malolactic fermentation, van Vuuren said.
But figuring out which wines to buy to avoid a histamine headache is no small trick. Winemakers who are using the new yeast are loath to admit it, fearing public backlash that sometimes accompanies genetic engineering. If you drink red wine from the United States or Canada, there’s a good chance you’ve tried ML01 wine already. Wine made with the new yeast does not require any special labelling.
“Several wineries in Canada and the United States are using the yeast,” said van Vuuren. He claims he doesn’t know which ones.
B.C. winemaker Howard Soon has been experimenting with test batches of wine made with ML01 at Kelowna’s Sandhill Winery, a premium label owned by Calona Vineyards. Soon told en Route magazine that genomics would become mainstream in B.C.’s wine-producing heartland within five years.
Commercial winemakers until now have had to ferment most grape juice twice, first with a wine yeast and then with a malolactic bacteria to convert tart-tasting malic acid to lactic acid, which has a softer mouth feel. But the secondary fermentation is often unstable, prone to stalling and can lead to the formation of toxic substances called amines.
“If they don’t get the malolactic fermentation going it can cause [carbon dioxide] to form in the bottle and the corks come flying out,” said van Vuuren.
Van Vuuren took a gene from malolactic bacteria and spliced it into the DNA of a wine yeast so the resulting yeast completes the alcoholic fermentation and the malolactic fermentation simultaneously. The new yeast eliminates the need for commercial wine makers to add malolactic bacteria and reduces the risk that toxic chemicals will form in the wine.