“You won’t make me sound mad, will you?” asks Wendy Cook, as we drive to the station from her Dartington home. Beyond the car windows, the Devon countryside rolls out and, where you and I might see weeds, for Cook there are rich pickings: nettles for dumplings and soup; wild garlic for pesto. Later will come sorrel, dandelions, elderflowers for “champagne”, hazelnuts for her special rice pudding.

As an enthusiastic forager and the author of The Biodynamic Food & Cookbook: Real Nutrition Doesn’t Cost The Earth, Cook can put a meal together without any taint of chemical pesticide, for next to nothing. In her latest book she is campaigning for an all-out return to hunter-gathering. She wants to draw people’s attention to the fact that since wild foods grow where conditions are most propitious they are rich in nutritional vitality. They are also the very model of the freshness and seasonality for which she is a glowing advertisement.

A warm, vibrant woman, with a mass of dark hair, she seems nothing like her 66 years. It would be easy to make her sound wacko, yet she embodies earthy good sense. She has been researching food and its effects on health and consciousness for much of her adult life. Her writing is eloquent and profound, but this is rarely the first thing that you will read about her.

After all, she was once married to the comic genius Peter Cook and — never mind that the couple divorced 35 years ago or that Peter died in 1995 — this still apparently defines her.

If this rankles, however, she makes light of it, laughingly recalling how she gave an interview three years ago to a national newspaper on the publication of her first book, Foodwise (Clairview, £16.95). The resulting article dwelt long on the couple’s marriage, their divorce, and Peter’s slide into alcoholism, with the merest glancing reference to “Cook, now a food writer”.

“It was like, ‘Oh, and Wendy’s written a book’,” she says with a smile.

Yet what a book! Foodwise ranges through history and across cultures, a synthesis of modern science and spirituality, philosophy and politics. She has followed it up with The Biodynamic Food & Cookbook. As the title suggests, this is part work of reference, an exploration of the principles of biodynamic agriculture, and part innovative cookbook, with recipes arranged according to the season.

Biodynamic farming, a holistic system proposed by the scientist and philosopher Rudolf Steiner in 1924, is explained in detail. The ethics of our modern food culture are critically examined. This is, in short, a recipe book set firmly within a moral — but not moralising — context. It may not sell half as well as her memoir of her and Peter’s early lives, to be published this autumn, but it should be required reading for anyone who cares about good food.

Embraced by chefs such as Michel Roux and health-conscious celebrities such as Elizabeth Hurley, biodynamics are being hailed as the “new organics”, although the biodynamic movement predates the Soil Association, the guardians of organic integrity, by 22 years. The aim of the biodynamic farmer is to create balance and harmony between plants, animals, human beings and the soil. The farmer works with Nature rather than trying to master it. As far as possible, the biodynamic farm provides feed for the animals, and the soil is fed with composted plant waste mixed with animal manure.

Cynics may hoot over the biodynamic philosophy, which emphasises cosmic forces and advocates planting and harvesting according to the cycles of the Moon. The idea of special preparations for the compost heap, made from, for instance, cow horns filled with manure and buried over winter, meanwhile, must have the cynics slapping their thighs with mirth.

There is one small problem, however, for the sceptic: biodynamic farming really appears to work. The chef Antony Worrall Thompson is a fan and a growing number of advocates believe that bio-dynamic produce is superior in terms of nutrient content, flavour, texture and last longer.

The concept of terroir may be helpful here. Few wine buffs doubt that a wine’s character depends directly on the content and quality of the soil in which vines grow. And lots of viniculturalists are turning to biodynamics, says Cook, in the hope of restoring superior quality by restoring exhausted soil — and the resulting wine can sell to connoisseurs for £50 a bottle.

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