Checking a bottle before you buy it.

A great label is a claim, not a guarantee. Between the estate and your table a bottle may have crossed three owners, two warehouses and a summer in a hot container. None of that appears on the front label, and all of it decides what is in the glass.

Five checks catch most of the trouble. A serious merchant will answer all five without being pushed. If they cannot, that is the answer.

1. Fill level. Wine seeps past a cork over decades, and heat accelerates it. For Bordeaux, into-neck or top-shoulder is normal up to roughly twenty years. Mid-shoulder on a wine that should still be young is a heat story, not an age story. Burgundy fills are read differently because the bottle shape differs, so compare like with like.

2. The capsule. Look for seepage staining beneath it and for a capsule that turns freely. A capsule that spins is usually fine. One that is stuck to dried wine is not. A capsule that looks newer than the label deserves a question.

3. The label. Cellar-damp labels with lifted corners and light mould are a good sign, not a bad one, because they suggest a cool humid cellar. A pristine label on a forty-year-old wine is worth asking about. Bin-soiled and nicked is honest. Uniformly perfect is sometimes reconditioned.

4. The paperwork. Ask where the wine has been stored, for how long, and whether it moved under temperature control. Ask whether it came from a single source or was assembled from several. Bonded warehouse records, an auction lot number, or an original purchase invoice all count. A shrug does not.

5. The seller's own terms. Read what happens if the bottle is faulty. A merchant confident in the provenance will take back a corked or maderised bottle. One who sells strictly as-is on wines above a certain value is telling you something about their own confidence.

What this costs you. Roughly one email. The reason to do it is not paranoia about fakes, which are rare outside the very top names. It is that heat damage is common, invisible from the front label, and unrecoverable. A wine that spent a month at thirty-five degrees is not a bargain at any price.

The same discipline applies when you sell or pass on wine yourself. Keep your purchase invoices, keep the storage records, and the next owner will pay for the certainty.