Hilbith poured the wine slowly, cautiously,
taking care not to let sediment fall into the glass.

You may have noticed sediment-like residue at the bottom of your wine glass and carefully tried not to consume it or avoid it by pouring your drink into another glass or carafe. Although these substances look unappealing and no one is willing to consume them, the sediment, or lees, as it is called, is completely normal and does not pose any kind of risk to our drink’s taste or to our wellbeing.

These lees swimming around in your glass, or just sitting there on the bottom, are just a normal result of a living red wine. Some of them are created during the vinification process and others during the aging process.

Sediment forming during wine production

The first case during which sediment is likely to form in your wine is that of wine production. It is created by dead yeast cells, proteins, stems, and other solids that have settled to the bottom of the fermentation tanks during vinification and are called ‘lees’.
Wine lees remain with the wine for a period of time causing it to develop a complex character. During the transfer of the wine in fermentation tanks, the lees are separated from it and it is during that process that other sediments can be created.

Sediment inside the bottle

The second case of sedimentation can occur during the aging of red wine in the bottle. This sediment comes from complex polyphenols that gradually fall to the bottom of the bottle. Polyphenols, which are characterised as beneficial and antioxidant for the body, are divided into two categories: anthocyanins (which are primarily responsible for the colour of red wine) and tannins (which have ‘bitterness’ and are astringent).

In any case, these sediments don’t destroy the taste of a wine, nor are they an indication of chemical compounds. The only reason they are carefully removed from the bottle through the transfusion process is mainly an aesthetic one.

How to remove it

Aged red wine probably has sediments inside the bottle. Lift it sideways in the direction of light and, if the glass of the bottle allows it, look inside. If you spot residue, place the bottle in an upright position for a few days to allow all the sediment to settle to the bottom of the bottle. When you decide to enjoy your wine, open it and carefully transfuse it into a carafe using a strainer, just like Ian Rankin’s hero Hilbith.

Sediment: ‘quality indication’

Sediments are generally found in wines that come from wineries which employ traditional production methods, i.e. minimal interventions. The difference lies in the fact that modern winemaking technology has now introduced new techniques, such as cold stabilisation and fine filtration that can remove tartaric acid. However, many wine lovers – especially of the Old World – consider sediments to be a sign of quality winemaking; this speculation isn’t really true, as a wine produced either by traditional or modern methods can be just as good.