Washed-rind cheeses are those that have a brine-washed rind. The technique involves moistening or curing of the rind in a solution of saltwater brine and/or mould-bearing agents that may include beer, wine, brandy or spices, making the surface amenable to a class of bacteria known as b. linens (the reddish-orange 'smear bacteria') that impart pungent aromas and distinctive flavours and produce a firm, flavourful (and usually reddish-orange) rind. Some cheesemakers include b. linens directly in their brine, while others introduce it to the milk prior to cheese-making. The process requires regular washings, particularly in the early stages of production, making it quite labour-intensive compared to other techniques.

Washed rind cheese with a high moisture content gets broken down by these bacteria, ripening inwards like those with white moulds, but resulting in a creamy cheese that becomes oozier with age (in as little as a few months). By comparison, low moisture washed rind cheeses (like Gruyère and others traditionally made in the Swiss and French Alps) become firmer and drier as they age.

Washed-rind cheeses are usually soft in character (such as Limburger), although there are some that are semi-hard or even hard (e.g. Appenzeller).

The same bacteria can also have some impact on cheeses that are simply ripened in humid conditions.