To a carnivore like me, some wines seem explicitly designed to put off vegetarians. The syrahs of the northern Rhône, for example, often have a note of bacon fat, pinot noir from Burgundy frequently has a gamey edge and a whiff of the farmyard, and Argentinian malbec is often described simply as meaty.

Apart from what might be their own revulsion, in many cases there's nothing to stop a committed vegetarian drinking wines that taste, to use another wonderful wine term, "animal". An increasing number of wines available in the UK are suitable for vegetarians; Tesco, the UK's largest wine retailer, puts the figure in its own range at more than 50%, although significantly fewer are suitable for vegans.

If that phrase – suitable for vegetarians – made you stop short a moment, I don't blame you. After all, apart from tasting notes, what does a product that is supposed to be no more than fermented grape juice have to do with animal products? Well, quite a lot as it happens.

The problem, if you're a non-carnivore, starts with what takes place at the end of the winemaking process. Most winemakers choose to clarify and stabilise their wines before they are bottled by using a practice known as fining. There are sound reasons for doing this: fining a wine not only makes a wine look clear, it also lowers the risk that it will take on unwanted flavours and aromas in the bottle before it is opened.

But it's the products used in the fining process that create a potential moral hazard for vegetarians. Though bull's blood, a traditional fining agent, was banned by the EU after the BSE crisis, a number of animal-derived products are still permitted for the production of wine sold in Europe. Among the most prevalent are isinglass (fish bladders), gelatin, casein (milk protein) and albumen (egg whites).

What complicates the issue further is that there is no obligation for winemakers to state whether they've used animal products on their labels. Which means that in many retailers or restaurants you have no idea whether or not a wine has been fined, or whether the fining agent was a veggie-friendly alternative (the clay-derived bentonite).

Things are getting easier for vegetarian wine drinkers, however. A useful place to start is veggiewines.co.uk – an amateur labour of animal love that has a long list of vegetarian and vegan wines (and beers, spirits and mixers) available in the UK.

Supermarkets are also increasingly savvy. The Co-op is the most transparent, and its back-labels clearly state both the list of "ingredients" in the wine, and whether it is suitable for vegetarians and vegans. Tesco, Marks & Spencer and Sainsbury's all state whether a wine is vegetarian or vegan, as does Asda for its own-label wines.

Outside the mainstream, the organic wine specialist Vintage Roots has a number of clearly flagged vegetarian and vegan options, while many of the wines at Les Caves de Pyrène (01483 554 750) and Artisan Wines (01244 851 557) are produced without fining or filtration.

Six vegetarian or vegan wines

Dr L Riesling, Ernie Loosen, Mosel Valley, Germany 2008 (£6.99, Majestic; £4.98 as part of a case; vegetarian)

A delightfully floral, light (under 9% alcohol) zippy Riesling. It's got quite a lot of sugar, but the acidity means you'll never notice.

Altos del Condor Sauvignon Gris, Trapiche Vineyards, Argentina 2009

(Marks & Spencer; £6.99, vegan)

Rounded, nicely nutty, fresh white from top Argentinian winemaker Daniel Pi.

Viñedos Organicos Emiliana, Coyam, Colchagua Valley, Chile 2006

(£13.50, Vintage Roots, vegan)

A stunning, biodynamically produced red blend of four grape varieties; one of Chile's very best wines.

Jean-Luc Colombo Les Gravières Crozes-Hermitage, Rhône Valley, France 2007 (£13.49, Waitrose Wine Direct, vegetarian)

Beautifully pure, precise but powerful Syrah with a core of dark fruit.

Cuvée Chasseur, Vin de Pays de l'Hérault, France, 2009 (£3.79, Waitrose, vegan)

Juicy, unpretentious, but extremely drinkable southern French red blend.

Tesco Finest Palestra Rueda Verdejo, Spain, 2009 (£6.99, Tesco; vegetarian)

Powerfully pungent, grapefruit-inflected modern Spanish white.

david.williams@observer.co.uk