Please excuse me if the following piece seems at all confused. It's just that much of the crucial interview bit was conducted under the influence of two bowls of sea-buckthorn and wild-pear sorbet. Which may sound like a dessert but is more of a super-tart, super-sweet legal-high equivalent to inhaling five espressos, a bottle of amyl nitrate and a Haribo Tangfastics megamix in one.
Such is the baptism of flavour during a day with wild-food expert Fergus Drennan. For more than two decades, he has devoted his life to ingredients of the uncultivated variety – consuming, researching, educating on and experimenting with them. And consume them he does: not merely simmering a few batches of nettle soup of a spring afternoon, but making acorn flours, walnut oils and leaf curds, to name but a few staples. Though he is mostly vegetarian due to his distaste for rearing animals for slaughter, he will consume roadkill, or "accidental meat", as he calls it – which means pheasant, badger, fox, rabbit and squirrel making impromptu appearances in his diet, too.
Anyone with a passing interest in food trends will know that foraging has been hot for some time now. That's in part down to Best Restaurant in the WorldTM, Copenhagen's Noma and its guru René Redzepi, whose back-to-nature gastronomy has influenced a generation of chefs. Though, reading the restaurant critics, you might detect them having had their fill of the "f" word: a 2011 article in Square Meal magazine, "What's the point of Foraging?", saw reviewer Marina O'Loughlin lament that, "Weeds are taking over: pools of sulphuric khaki sludge are appearing on the UK's most fashionable tables."
Yet such questions of culinary faddishness have little to do with Drennan's endeavours. For him, foraging is not a hobby of the here-and-now but rather a timeless tradition and a fundamental means for us all to wrest control of what we eat. Something which, in the light of Horsegate, seems more pertinent than ever. "So much of what I am doing is about connection," he says. "You point to any of the [foraged ingredients] here and there's a story. Now when I'm eating that food, I'm reliving that story – of where it came from and what happened when I was gathering it. You get something from Tesco… there's no story there."
Nor does his interest in wild ingredients stop at the plate. Rather, staunchly opposed to our waste culture as he is, he will crush, boil, bathe and stretch his daily harvest to unleash its full potential, as becomes clear from a visit to his bungalow in the Kent village of Chartham. A cramped converted garage, it is also a cornucopia of curios – among them a badger hide, stretched out on a frame and waiting to form the top of a traditional Irish bodhran drum; pieces of mushroom paper written on with mushroom ink; and a strip of shimmering brown material dangling from a bookshelf that looks like seaweed but is actually half a fox intestine, set to form part of a traditional gut parka jacket.
"The problem with me," notes Drennan "is that I have an exciting idea every month and they all take a lot of commitment and time." At the moment, said ideas include a clothes project, involving making whole outfits out of roadkill; a book project, to produce an entire wild-food guide itself made out of wild materials; and, most pressingly, his One Year Total Wild Food Experiment.
But more of that later. For now, Drennan has the arguably lesser challenge of leading a mollycoddled, metropolitan journo on his first foraging expedition. (First, that is, if you discount the odd childhood blackberry-picking afternoon and pretend consumption of yew berries so as to wind up his parents.) We have a vague plan of ingredients to collect for lunch, though really it's a matter of what catches Drennan's roving eye. We've barely been driving a minute before he spots a roadside bank replete with cow parsley, jumps out of the car, and scoots it up with the light-footedness of Errol Flynn, to borrow the photographer's comparison, while I clump along behind.
The rest of the morning follows suit, with Drennan doing the majority of leg – or rather hand – work. By the banks of the River Stour on the edge of the village, we gather some jelly ear mushrooms growing from a collection of tree stumps, their caps shinily Lurex-like, before picking some common sorrel and stripping some catkins from the branches of a picturesque weeping willow.
Then it's on to his friend's semi on a suburban street in Canterbury, where he has been tapping a birch tree in the garden for sap. He detaches a full bottle and tubing from a hole drilled into the trunk; later, he will boil this down into syrup, though for the moment, he gets me to chug some of the brownish liquid down. In the day's only disappointment, it tastes of absolutely nothing. "Sap is about 95 per cent water," he explains. "I think a lot of people confuse sap and resin, because in non-botanical articles, people use the terms interchangeably."
Finally, we head up to the north Kent coast, where we pick some stems of alexanders, a celery-like vegetable, and yellow gorse flowers from a clifftop, before driving a couple of minutes down the road to harvest some sea beets from beside a track. Such is Drennan's enthusiasm – "Just look at that happy, wonderful, joyous sunshine colour," he says as we scrabble among the spiky gorse bushes – that he makes the plants sound less like plants and more like cherished stalwarts of the local community.
Meanwhile, there's something a tad Terminator about the way he describes his ability to keep tabs on the local ecosystem. "You know how you get those apps on your phone where you can layer [different maps on to each other]. Well I've got a big map of Kent [in my head like that]. [I'll have one layer] with where the chanterelles are, and another with all the walnut trees and so on. I did have a physical map, but it had so many things on it that I thought I'd memorise [everything instead]." Not that there aren't always new discoveries to be made. "People ask me: 'Why don't you ever go on holiday?' but I find the more and more you forage, the more and more you only have to walk a few paces and a kaleidoscope appears."
Spending his early childhood in suburban Wimbledon before moving to Kent, aged seven, Drennan first became acquainted with foraging when he would collect dandelions for his pet tortoise on the common. "It gave me a unique appreciation of plants as something beneficial," he says. "I didn't really have a concept of weeds."
After finishing school, a catering course stoked his enthusiasm for natural ingredients, though it was truly set alight while he was studying at university in Wales. Broke in his final year, he saved on accommodation costs by living in a tent, while subsisting on local greens and fungi, alongside rejects from an organic-food distributor and leftovers from the student-union canteen.
Then, after a soul-searching period living and teaching in China, he returned to England and found a job selling vegetables at a stall at Canterbury's Goods Sheds k farmers' market. Selling his own hand-picked fungi and wild syrups and cordials on the side, he met another local forager in Miles Irving, and subsequently went into business with him, supplying produce to top restaurants including The Ivy and Fifteen. After a few years, however, Drennan decided to pack it in, partly due to his concern over the pressure to over-harvest when foraging on such a scale, but mostly because he found himself dulled by the routine. "You knew your week was planned out – that you'd be on the forest floor picking wood sorrel for two days because everyone likes wood sorrel – and I just realised, 'I'm doing something which I'd thought I'd always be passionate about and I actually feel now that I'm at work like normal people.'"
These days, on top of his various projects, he gleans what income he can from running day-long foraging courses and writing magazine articles. He is as "poor as a church mouse", he says, but happy to be his own master. Indeed, he credits foraging with helping him overcome acute shyness; at some point, he would like to work with organisations such as Mind to devise a foraging-therapy programme. "I've been out with friends with mental-health issues, and I've seen it be incredibly beneficial – therapy for me is a means of drawing you out of your whirlpool of self-referential loops of thought and connecting with the natural world is a great way of doing that."
And so back to the One Year Total Wild Food Experiment, the mother of all his endeavours, in which he will attempt to live off nothing but foraged ingredients for 365 days, starting on his birthday, 22 October. It's his third shot at the challenge, his attempts in 2008 and 2009 being cut short by a back injury and lack of funds, respectively. This time, he is pre-empting such a shortfall by using crowdfunding to raise £12,000 towards both living and research expenses. As far as the diet itself goes, he is confident he will cope: he says the things he will miss most are ginger, chilli and coffee, though he doesn't anticipate any nutritional deficiencies, given Kent's rich biodiversity and the skills he's acquired over 22 years. "You've got to be creative to get the full potential out of plants, but in order to do that the mind can get into this buzz of possibilities, so you need to calm it down," he says. To aid this, he has already started regular meditation sessions.
And as to the aim of the project? The overarching objective is to explore the extent of the role foraging could – and should – play within the modern world. Drennan will carry this out using the structure of themed months – one going wholly raw and vegan, for example, and another urban-foraging in London.
Then there will be more obviously crowd-pleasing elements, such as creating wild doppelgangers of processed foods such as Marmite and ketchup, and going nomadic in the Scottish wilds. All the while, he will blog about his experiences on his website, with the intention of publishing a book at the end of the challenge.
What he does not want to do is engage in indiscriminate cheerleading: rather, he'd like to explore the pitfalls of a foraged diet as well as the benefits. One potential trouble is the bioaccumulation of toxic chemicals in "natural" ingredients that can occur due to land pollution. "Nowadays we're in this ironic situation where you can have scientifically grown food in impoverished soils that, while not being wonderfully good for you, might actually be better for you than something in the wild that's way over the limit in terms of heavy metals." To this end, he plans to have his hair analysed for heavy-metals content. "Who knows, by the end of the project, my lead levels might be off the scale and in two years, you'll ask me my name and I won't remember… but hopefully that won't happen."
At the same time, it's clear he hopes the project will prove broadly encouraging to us chicken-Kiev-and-a-packet-of-salad types. Indeed, he plans to call on members of the public to join him for short periods and document their own experiences. To what extent does he think the apparent interest in foraging has trickled down from haute cuisine to the general populace, I wonder? He says he has noticed more people out and about, particularly on the hunt for fungi, "though you have to be careful", he jokes, referring to a recent occasion picking morels. "There were quite a lot of men stamping around and I thought, 'Oh yes, more foragers,' but it turns out it's a gay pick-up spot."
And what about sustainability? After all, if Redzepi, Drennan and others were to inspire a mass descent upon the nation's hedgerows, what are the chances of us harvesting species to the point of depletion? Drennan says the issue is "nuanced" with "no simple answer", though any consideration of it must be "offset against the fact the modern industrialised agriculture system is completely unsustainable". He remains wary of commercial foraging, but when it comes to amateurs, he favours education and common sense over further regulation. He also believes overstated conservation concerns can distract from the more fundamental issue of people having a stake in the land; that they might see their habitat as "a museum" will prove more damaging to the environment in the long run.
As to the whole "middle-class hobby" tag that foraging has acquired, it "bothers him immensely". ("Let's get in a time machine and go back to Paleolithic times and point at them and say you flipping middle-class wankers!" he jokes.) After all, at heart it is the most "radically egalitarian" of activities, he says, "a good awareness of things" and "a childlike sense of wonder" being the main requirements. Naturally, he has the first stirrings of a project to promote such egalitarianism, though he is cautious not to get ahead of himself for now.
Really, though, for all the other, bigger issues at stake, the virtues of foraging are confirmed by the meal Drennan serves up. The proof being not just in that aforementioned adrenaline shot of a pudding but all the dishes he prepares for us when we head back to the bungalow – a mixture of things dreamt up from the morning's harvest and others made earlier. There's a salad composed of, among other greens, sorrel, dandelions, wild garlic and alexanders, and set off by bright-yellow gorse flowers and bright-red pickled rosehips; rock oysters with shells the size of a bouncer's fist, cooked, then detached and accompanied by sea beets, laver seaweed, alexanders, lacto-fermented wild garlic and an assortment of wild pickles; and a turkey-tail mushroom and laver-seaweed consommé filled with jelly-ear, morel and penny-bun fungi and flavoured with the likes of "fermented dwarf-quince juice" and "lacto-fermented wild-garlic liquid seasoning".
All of which intricacy may make Drennan sound like some kind of MasterChef contestant from another dimension: indeed, I feel, disconcertingly, a bit like Gregg Wallace, as I watch him frantically plate up, at one point trying and failing to make a sailboat garnish composed of some mushroom paper stuck into a jelly-ear mushroom cap floating on the consommé. Yet for all the menu's apparent complexity, there is an exhilarating purity of taste, from the sweet-saltiness of the oysters and greens to the pungent smokiness of the soup. One Ginsters bacon sandwich and leftover portion of Jamie's 30-minute crispy salmon later, and, as I go to bed, these are the things still rolling around my palate. As are, indeed, the stories…