"English wine," emphasised Nigel, my guide at Biddenden Vineyards, correcting my mistake. "British" wine, he was keen to point out, can be made using grapes flown in from anywhere in the world. As we wound our way through Biddenden's vineyard, I began to understand his eagerness to clarify my misapprehension.
While the Romans had vineyards spread widely across Kent by AD250, they left no legacy of wine-making. So when the Barnes family planted their first acre of vines in 1969 they were true pioneers, going about it through a process of trial and error. The biggest question hanging over them was whether it was really possible to grow vines in the English climate: a late or early frost can ruin a crop.
Four decades on, and Biddenden is now the oldest commercial vineyard in the county, with 22 acres of vines. Kent now has more than 350 acres of vineyards, and English wines are raking in international awards (including two gold, 14 silver and 20 bronze medals at the 2011 International Wine Challenge, the Oscars of the wine world). To celebrate all this vinery, English Wine Week starts today.
It's all very exciting for oenophiles. As Julian Barnes, second-generation wine-maker at Biddenden, explained: "While the varieties of grapes are German [such as ortega and dornfelder] or French [such as pinot noir] they are grown in England – and the local conditions and soil influence the flavours of the wine."
In Biddenden's farm shop, shelves heave with local produce including the farm's own wines and ciders (all free to taste). "What produce is Kent famous for?" asked Nigel. "The same nutrients they take from the soil are going into the grapes that make the wine." With one slurp of the Gribble Bridge Ortega 2009, I understand: apples, pears, elderflower. The 2007 Pink Sparkling has hints of strawberry. You can't get more English than that.
Shopping bags clanking, my designated driver and I left Biddenden, and zigzagged (soberly) through the Kentish countryside passing oast houses rising from golden fields of oilseed rape.
Just past Tenterden on the B2082, a blink-and-you'll-miss-it sign advertises Harbourne Vineyard. As we pulled into the drive, wine-maker Laurence Williams emerged from the tiny shop built on to his family home. He pointed to a spot on the hillside where Henry VIII's boatyard once stood, explaining that his 1.2-acre vineyard – five miles from the coast – is growing on what would have been the seabed.
In the shop I tasted the Harbourne Old Vines Rosé – 25-year-old vines producing a complex dry taste with plum flavours – and a citrusy Seyval Blanc Dry 2005. Laurence's wines are made using traditional methods with minimal intervention and, he says, "The grapes are crushed gently so there's no risk of getting off-flavours from crushed pips or stalks."
Next we turned west towards Tunbridge Wells, to Sandhurst Vineyards, which is set in a patchwork landscape of raspberry canes, cherry orchards and hop fields. Anne Nicholas, the owner, led me to a homely bar and let me sample Sandhurst's wines and ales. She tempted me with a summery bacchus and a spicy pinot noir; I left with a bottle of each.
Further west we were directed to Lamberhurst Vineyards. A restaurant, shop and spa are due to open there in June; instead we followed a signposted walk through the peaceful vineyards with views across the Teise Valley.
That night, Tunbridge Wells provided further immersion in my theme. The Hotel du Vin & Bistro has its own tiny vineyard. At dinner the sommelier, Victor, revealed that he was planning to make the hotel's own sweet wine with next year's harvest.
The next morning we made for Chapel Down, which has established itself as a world-class winery (winning one of those gold medals at this year's International Wine Challenge for its Rosé Brut, reportedly served at the royal wedding last month).
It's possible to spend a day here exploring the vineyards, picnicking on local delicacies bought from the shop or lunching at Richard Phillips' restaurant, where the Michelin-starred chef serves modern takes on English classics, such as braised Kentish lamb shoulder or whole native lobster. My guide, Jo, lead me through vines and warehouses – and Chapel Down's enormous success quickly became clear: 120 acres of vines across Kent and Sussex; crates of the stuff marked for Waitrose and Marks & Spencer; shiny new machinery everywhere. And then there's the wine itself: a fragrant sparkling Pinot Reserve 2004 with hints of strawberry and baked apple was my favourite.
The wine route through the Garden of England is an intoxicating mix of technology (Chapel Down's science lab and thrumming machinery), home-spun charm (Biddenden's family enterprise) and the great outdoors (Harbourne's focus on natural methods). One thing the wine-makers all share is a passion, not just for wine but for English wine. I'll drink to that.
Travel essentials: The Kent wine route
* The A21 connects the M25 with this part of Kent.
* Southeastern runs direct train services from central London to Tunbridge Wells or Staplehurst.
Staying & sampling there
* Biddenden Vineyards, Gribble Bridge Lane, TN27 8DF (01580 291726; biddendenvineyards.com). Free tours and tasting every second Saturday from 10am. Shop open daily. The self-catering Vineyard Loft can also be rented from £140 for two nights.
* Hotel du Vin, Tunbridge Wells, Crescent Road, TN1 2LY (01892 526455; hotelduvin.com). Doubles from £110, including breakfast.
* Sandhurst Vineyard, Hoads Farm, TN18 5PA (01580 850296; sandhurstvineyards.co.uk). Guided tours from £3, including wine tasting, by prior arrangement.
* Chapel Down, Tenterden Vineyard, TN30 7NG (01580 766111; englishwinesgroup.com). Hour-long tours from £9, daily. Open 10am to 5pm. Accommodation at nearby
* Sissinghurst Castle Farmhouse, TN17 2AB (01580 720992; sissinghurstcastlefarmhouse.com). Doubles start at £125, including breakfast.
* Harbourne Vineyard, Tenterden, TN30 7NP (01797 270420; harbournevineyard.co.uk). Free daily wine tasting at the shop.
* English Wine Week runs until 5 June. For details, see englishwineweek.co.uk.
* Kent Tourism: visitkent.co.uk.
* Download a free map of the Kent wine route at producedinkent.co.uk.