It was almost fifteen years ago that I sat, eating soft-fleshed olives and briny feta, with Christos and Lambrini Lagelou. Midday was drawing on; it was the Feast of the Exaltation of the Cross. The Aegean is warm on September 14th; priests hurl crosses into the blue water and lithe young divers retrieve them, in memory of the moment in 325 when Emperor Constantine's mother Helen unearthed Golgotha, buried beneath the pagan Hadrian's temple to Venus.

We, though, were some miles from the breeze-ruffled sea, and the air of inland Attica was thick with tiny forest flies. Christos lunged at them maniacally with a pink plastic swat. Up above us, Aleppo pines swarmed over the bright mountainside, greedy to drink the vaults of milky light above. And behind us, in a crowd of buckets in a ramshackle shed, there was enough pine resin to flavour 24 million bottles of retsina.

The moment was, for me, a kind of pilgrimage. Wine sophisticates are meant to disdain retsina as a dull wine vulgarly adulterated. I revere it. First, because you can sometimes have a surfeit of sophistication, and a tumblerful (it must be a tumbler) of retsina is an unrivalled antidote to the gallop after dreary superlatives and laborious nuance. Second, because I like the piney aroma and taste; it's cousin to the oily, bittering hum of the hops of old England, and in food terms akin to the spiking of fat lamb with rosemary.

It ventilates the digestive tract, settles the stomach and fumigates the spirits. And third, because no other drink connects us quite as faithfully to dinner with Plutarch, Theophrastus and - who knows? - perhaps even wily old Homer himself, parched after an evening's firelit recitation. I like the idea that I can go drinking, book and glass in hand, with the greatest tale-teller of them all.

Christos is the man who taps the trees for Kourtakis, Greece's largest producer of retsina. It's a simple enough task. First, find your tree, which won't be difficult: Pinus halepensis frames the Mediterranean like green stubble round a wide blue mouth, digging its roots into rock always too dry for the voluptuary trees of the north. Next, make a small cut in the tree with a double-headed pick, then knock in a collecting tray just beneath the wound.

The pine will bleed a little colourless resin into the tin, then heal in a fortnight; the resin forms sticky white lumps in the warm air, like cake icing. The collector returns three weeks later, makes a new cut just above the old one, and the process is repeated. After a while, the tree looks like a laddered stocking, but carries on growing happily enough.

In the winery, things are barely more complicated. Retsina from Attica is made from Saviatanó grapes, Greece's most widely planted variety, a kind of vegetable camel of the vineyards, able to pad through a fierce summer with barely a sip to drink. It makes nice enough wine - but the resin brings interest. It sharpens its edges; it perfumes and deepens the flavour. Sometimes, a little of the dark-skinned Rodítis variety is used as well, especially for pink (or kokkinéli) retsina.

The resin is added to the juice, and dissolves with the heat of fermentation and the march of alcohol; afterwards, the residues sink with the lees. Today's retsina contains about 0.15 per cent resin (1 per cent is the legal maximum); at the end of the eighteenth century, a resinated wine might contain as much as 7.5 per cent, which explains why the nineteenth-century traveller Edward Dodwell complained of a wine "so impregnated with resin, that it almost took the skin from our lips."

If you only learn one Greek word to team with retsina, it should be droserótita, which means 'cooling freshness'. Just like mint, resin has a pseudo-cooling effect on the tongue, simulating a drop in temperature while engendering no such thing. The same is true of mastic, the resin which seeps from bushes of Pistacia lentiscus on the island of Chios and which you can still buy in little bags in Greece, like crystals of edible incense: it was Europe's original chewing gum. In order to achieve droserótita in retsina, though, it is very important that there is a flavour balance between the shy, lemony fruit of the wine itself and the resin.

If you over-chill retsina, paradoxically, it will indeed taste like thinned turpentine and lack the delightful cooling freshness of a gently chilled tumblerful. There seems, alas, to be no scientific support for my own theory of retsina's especially healthful properties, though Lawrence Durrell, drawing on years of experience, maintained that "it is mild, and you can drink gallons without a hangover; nor does it provoke the disgusting, leaden sort of drunkenness that gin does - but, rather, high spirits and wit. If you drink rezina you will live for ever, and never be a trial to your friends or to waiters." (Perhaps Durrell didn't drink quite enough. He died in 1990.)

All the evidence is that for the ancients, the resination of wine was as much a necessity as a choice - it helped preserve it in the days when every wine was constantly threatening to turn to vinegar, and it helped cover up the repellent flavours which were the consequence of inadequate winemaking hygiene. Neither now implies - which makes it all the more endearing that we still love the whisper of the pine tree in our wine, and cling to the memory of grave men seeking respite from the bitterness of existence, 2,500 years ago, with the same cooling draught.