Dan Barber, a chef and owner of the Blue Hill restaurants in New York and a prominent writer on food and agricultural policies, urged his listeners to become picky eaters.

In a speech in the Science and Cooking lecture series on Monday, Barber asked his audience to demand the high-quality flavors that he said can only be produced by local farms using sustainable methods.

“For the most part, in the last 100 years or so, we have killed flavor,” Barber said.

This “death of flavor,” Barber said, is caused by the chemical additives, particularly fertilizers, which are used extensively in modern food production.

Barber emphasized the importance of natural microorganisms in soil, which help develop healthier produce with better flavor. In a natural cycle, matter that is decaying in the soil is consumed and then excreted by numerous organisms until it is eventually broken down into very refined nutrients that plants can absorb from the ground, Barber said.

Not all of those nutrients can be replaced by synthetic fertilizers, according to Barber.

He also said that animals that graze in the wild grow to be more flavorful than those that dine on cheap feed.

These ideas are put into practice at Stone Barns, an 80-acre farm in New York which supplies much of the food used at Barber’s restaurants. Fifty acres of its forests are set aside for pigs to forage for their own food.

At the lecture in the Science Center, Blue Hill’s Culinary Director Adam Kaye held up a rotund pig leg raised at Stone Barns. Prepared as speck, a type of ham, the meat had been cured with salt, juniper, and rosemary, then smoked for five days.

“Absolutely delicious,” said Quicia Davis, a healthy eating specialist at Whole Foods, as she tasted the meat. “You can definitely taste the love and the care in the speck.”

Harold McGee, who wrote the textbook used in the “Science and Cooking” course, introduced Barber to the audience.

“We’re on the verge of a renaissance in farming,” McGee said. “Dan Barber and Stone Farms have been real pioneers in this movement.”

Yet audience members questioned whether production methods like Barber’s are feasible on a large scale due to their high costs.

Current farming practices are designed for high yield, which often conflicts with a chef’s quest for good flavor, Barber acknowledged.

But he argued that sustainable farming could become the less costly option in the long run, since fertilizer production relies on fossil fuels—an increasingly scarce resource.