GRAPEVINE

"ARE you tasting the gins as well. Can I help?" asked a local, leaning on the bar. I was buying a take-away bottle of Britvic tonic from the village pub to set alongside Schweppes and some supermarket brands. "I've done the gins already." "What was best?" "Beefeater and Tanqueray, I thought." "I like Beefeater myself," chimed in the landlady. "It seems to have more flavour."

More, and nicer, I'd say, after sniffing then tasting through a line- up of a dozen gins twice over, a first set cut with water, then another lot with tonic. Beefeater and Tanqueray were my two winners by lengths.

I'd checked up on how distillery experts taste their gin. Well, they don't actually taste, they sniff. Gin comes off the still at 82 per cent alcohol, more than twice the strength of most you can buy. At this strength, the aromatic constituents are held in the gin by the alcohol, rather than leaping out as perfumed vapours. So the blenders dilute it with de-mineralised water down to between 20 and 26 per cent alcohol. Tulip-shaped glasses, only about a fifth full, trap the escaping aromas. Some gin blenders swirl the glasses to release the aromas, then top them with glass covers and leave them 20 minutes before sniffing. Others cover the glass top with one hand, shake vigorously, and sniff straight away. And that's that. Gin rarely passes their lips - when on duty, anyway.

Being an impatient kind of person, I used the quick and messy method, and it did pass my lips. I finished with a gin-soaked towel over my shoulder, a full mini-spittoon, and a clear preference for Beefeater and Tanqueray, with Plymouth Gin coming in a whisker behind. I was less keen on Gordon's, and unimpressed by Bombay Sapphire, White Satin and various supermarket brands, though I'd buy Tesco's very pleasant London Dry Gin (pounds 8.29 at 40 per cent alcohol) if economising.

There's a refreshing, delicate, citrussy tang to Beefeater (around pounds 11 in most wine chains and supermarkets, 40 per cent alcohol), a bit like lemon marmalade, subtly combined with juniper and coriander. Tan-queray (around pounds 15.50 Thresher, Wine Rack and Bottoms Up, Harvey Nichols, Selfridges and leading branches of Sainsbury and Tesco, 47.3 per cent alcohol) is also delicious, less citrussy and with marked juniper and coriander flavour. Tanqueray sells at a higher strength as most goes to the US, where they like their gin strong. Plymouth (around pounds 9.99 Thresher, Wine Rack and Bottoms Up nationwide, and Tesco in the south west only, 40 per cent alcohol) is quite different, very flowery and perfumed, too aromatic to my taste to drink with tonic .

Several of the supermarket gins had a slightly dirty taste - probably the mark of cheap coriander, according to Hugh Williams, the master distiller responsible for both Tanqueray and Gordon's. Cheaper supermarket gins are generally sold at 37.5 per cent alcohol to qualify for less duty (duty rises in proportion to the alcohol; hence the much higher price of high- alcohol Tanqueray). The cheaper ones also often had a strong flavour of citrus peel that disappeared quite quickly once the gin was mixed with tonic or water.

These cheaper gins are often "cold-compounded" rather than distilled in the traditional way. "Con-tract producers just take a vat of alcohol and add a laboratory-designed essence or a concentrate," Williams says. "The quality's not very good." Desmond Payne, the distillery manager at Beefeater, adds: "Cold-compounded gins have quite a strong flavour initially, but it soon goes off. They're rather harsh and slightly artificial."

The major brands, and by law anything labelled "London Dry Gin" (including the more expensive of the supermarket gins), are distilled. A top-secret combination of carefully selected seeds, peels and roots is steeped in a vat of alcohol for about a day, then on goes the heat and off come the vapours. "We sniff usually every half hour during the distillation," Williams says. "Different flavours come off at different stages, and we can tap off the parts of the distillation that we want. If we find a point at which there's an unwanted aspect of juniper flavour coming off the still, we stop collecting the distillate for that period."

The head distiller then blends together different batches of gin from 20 or so separate distillations to match the typical taste of his brand. But that's not the most skilled part of a blender's job, nor the most decisive, Desmond Payne says. "I spend much more of my time buying the botanicals. That's one of the most critical parts of the job. The juniper crop is different every year, and different from location to location. We buy many different parcels of juniper and put them together to get the character we're looking for. It's like blending tea."

Most of his juniper comes from Italy, especially Tuscany and Umbria. It grows wild in the hills, where it is picked by Italian families and sold to brokers, from whom Payne buys. "We look at it, check for ripeness, size and quality. We crush it and measure the moisture - we want the oils without too much water. Then we distil the oils off, and nose them, and order 15 tons of this one, 12 of that and five of another."

Juniper is the major flavouring for most gins - the word "gin" comes from the Dutch for juniper, genever. But Beefeater has a higher proportion of coriander than most, which adds its own orangey aspect to the orange flavour of the peels. Corian-der is the hardest to get right, according to Payne. It comes from Bulgaria, Russia and Romania. Then there's angelica root and seed from Saxony and Belgium, orris (part of the iris family) and various other seeds, roots and peels.

You might expect Real Gin men like Williams and Payne to drink their gin with water off-duty as well as on. But no, tonic is OK. Desmond Payne admits to the occasional glass of Beefeater and water, but drinks mostly strong gin and tonic - about half and half. Hugh Williams has the odd Tanqueray on ice, but his favourite is Gordon's and tonic, with lots of ice and a slice of lime.

So what about the tonics? I suspect it's no coincidence that the distillers I met seemed to use Schweppes. I did try others. Britvic was too sweet and tasted of bitter lemon. Waitrose, Sainsbury's and Safeway tonics were quite good, but a shade too sweet. For me, nothing beats Schweppes, with its not-too-sweet balance of lemon and quinine flavour. Whichever tonic you use, chill it, to avoid ice cubes diluting your perfectly crafted drink.