Natural wine generates more heat than any other topic in wine, and a lot of the argument happens because the term has no legal definition and everybody is discussing something slightly different.

Let me try to be useful about it, as somebody who drinks a lot of it and also thinks a fair proportion of it is not very good.

What people generally mean

There's no official standard, but the working consensus covers roughly:

Organically or biodynamically farmed grapes, usually hand harvested. Fermentation with ambient yeasts rather than commercial cultures. No or minimal additions — no acidification, no chaptalisation, no enzymes, no fining agents, no added tannin. Minimal or no filtration. And crucially, very low or zero added sulphur dioxide.

Some countries have introduced voluntary certifications with specific thresholds. Most natural wine is sold without any certification at all, which means the label tells you nothing and you're relying on the importer or retailer.

The sulphur question, which is the crux

Almost every disagreement about natural wine reduces to sulphur dioxide.

SO2 has been used in winemaking for centuries. It does two things: it's an antioxidant, protecting wine from browning and oxidative deterioration, and it's an antimicrobial, suppressing spoilage organisms.

Reducing or eliminating it removes both protections. That's a legitimate choice with legitimate reasons — some winemakers find that sulphur mutes aromatics and that wines without it have more immediacy and vitality. Having drunk plenty of both, I think there's genuinely something in this.

The cost is that the wine is fragile. It's more vulnerable to oxidation, to refermentation in bottle, and to spoilage organisms. It needs cold storage throughout the supply chain and it can change substantially between one bottle and the next.

So low-sulphur winemaking requires much greater precision in the cellar, not less. The best natural producers are meticulous. The worst treat "no additions" as licence for inattention, and the results are predictable.

The faults, and how to recognise them

This is the practically useful part, because the natural wine conversation is bedevilled by faults being reclassified as character.

Volatile acidity. Acetic acid, produced by acetobacter. Smells of vinegar or nail polish remover at higher levels. Small amounts add lift and complexity; the threshold above which it becomes unpleasant varies between people but it's real.

Brettanomyces. A yeast producing compounds that smell of farmyard, plaster, band-aid or horse. Some people are much more sensitive than others, which is why arguments about brett are so intractable. At low levels it can add savoury complexity. At high levels it strips fruit and everything tastes the same.

Mousiness. The distinctive natural wine fault. Caused by certain bacteria producing compounds that are undetectable on the nose but appear after swallowing as a lingering taste of stale grain or, unfortunately, mouse cage. It builds and doesn't fade. Not everybody can detect it — sensitivity varies with saliva pH — which causes genuine disagreements where one person is repulsed and another perceives nothing.

Refermentation. Residual sugar plus live yeast plus warmth equals a still wine that arrives slightly fizzy. Sometimes charming, usually not intended.

Excessive reduction. Sulphur compounds giving struck match, rubber or drain smells. Often blows off with air, sometimes doesn't.

Fault or feature?

My honest position, which annoys people on both sides.

Small amounts of these compounds can genuinely add interest. Wine is not supposed to be sterile, and the pursuit of technical perfection produced a lot of very clean, very boring wine in the late twentieth century. The natural movement was a necessary correction.

But a fault is a fault when it dominates. If every wine from a producer smells of the same farmyard note regardless of grape or site, that's not terroir — that's brett, and it's masking exactly the expression of place the philosophy claims to prioritise.

The test I use: does this wine taste of somewhere, or does it taste of a process? If several very different wines all taste the same way, the process has won.

What's genuinely good about it

I want to be clear that I'm broadly sympathetic, because the criticisms above can read otherwise.

The movement has revived obscure grape varieties that industrial viticulture had abandoned. It's brought serious attention to farming practices, which matter enormously and were neglected. It's produced wines with a directness and energy that conventional winemaking often smooths away. And it's made wine culture considerably less stuffy and more welcoming, which is not a small thing.

Some of the most memorable bottles I've had in the last decade have been low-intervention wines from small producers, and they didn't taste like anything else.

How to buy it

Practical advice, since the label won't help.

Find a retailer who tastes what they sell and trust them. This matters far more with natural wine than with conventional, because variation between producers is enormous.

Store it cold and drink it sooner rather than later.

Expect bottle variation and don't write off a producer on one bottle.

And if something smells wrong to you, trust yourself. The fact that a wine is fashionable does not oblige you to enjoy vinegar.