Linda Crago knows hot peppers. She grows so many varieties at her Tree and Twig Heirloom Vegetable Farm in Niagara that she’s lost count of how many are planted – more than 75, she estimates, including Yellow Bhut Jolokia and a strong contender for the hottest pepper in the world, the Trinidadian Scorpion.
But even she is a bit surprised at this year’s crop. They’re early. Usually she harvests them in September. She was already sampling some last week. The other discovery is taste: “They have an incredible kick to them. I would say much more intense than last year’s,” she says.
It’s not just peppers that taste different. Her Red Tail radishes are so spicy they burn and the tomatoes are sweetly intense, she says.
Hot and dry drought conditions may be devastating crops in parts of Canada but the fruit and vegetables that do survive the lack of rain and sweltering heat feature stunning flavours.
The reason for this is a bit of a chemical mystery, says Dr. Susan Murch, an associate professor of chemistry at the University of British Columbia in Okanagan and Canada Research Chair in Natural Products Chemistry.
You’d think we’d know a lot about plants by now, but it turns out there’s still a lot to discover. A plant contains around 30,000 chemicals, of which we only know something about roughly 1,400. “The rest are a complete mystery,” says Dr. Murch.
The gist of it is that plants produce chemicals in two groups: primary metabolites are required for growth and reproduction, and include such substances as sugars and proteins.
Secondary metabolites include all the things the plant makes that aren’t required for growth and reproduction. Molecules in this group help the plant survive drought and cold, discourage insects, prevent fungal infections and create vibrant colours to attract pollinators.
“In general, plants make more secondary metabolites when they are stressed and it is these compounds that produce interesting flavours,” Dr. Murch says.
So when the sun bakes Ms. Crago’s peppers for weeks on end, secondary metabolites, capsaicins and capsaicinoids will build up, resulting in a greater kick of heat. One theory for this phenomenon, says Dr. Murch, is that when a pepper or radish is stressed and vulnerable, it uses this heat as a defence against bacteria and fungal infections, or simply to discourage us from consuming them. “Most plants don’t really want to be eaten,” she says, pointing out that most plants have defences against predators.
Another effect of the hot weather is smaller produce, something chef Scott Bagshaw noticed with cabbage and kale at Deseo Bistro in Winnipeg, which sources their produce from local independent farmers. Not enough water led to a drop in primary metabolites and stunted growth, but resulted in a “flavour that was more punctuated,” he says.
With stressed berries, a spike in secondary metabolites also means a boost in taste and colour. Local strawberries in Halifax have been a near obsession for chef Darren Lewis of Chives Canadian Bistro. They’re a deep red all the way through, he says, and are “the best of the best.” He’s been using them in everything. “In gelato, sorbets, salads, panacotta, chutney, jam, you name it. We have even been featuring a strawberry mojito all month.”
Given the devastating downside of this summer’s weather, it’s a tiny, tasty upside.
Special to The Globe and Mail