A. It is a natural dye derived from the annatto seed, and does not alter the taste of the cheese. In the summer the grass-fed cows produce a richer coloured milk (from the carotene present in fresh grass) In the winter the cows are fed hay which results in the production of a paler milk, slightly less rich in vitamins and flavour. Centuries ago this meant that the summer milk fetched a higher price on the market. Crafty farmers would put a very tiny amount of annatto into the winter milk before making the cheese to give it a creamy hue - the impression that the cheese was made with summer milk. This most probably simply got out of hand and over the years as red cheddar became a cheese in its own right. It is generally held that he finest Cheddar is undyed and has a protected designation of origin (PDO) in Somerset, Dorset, Devon or Cornwall. For more info on Somerset Cheddar, West Country see www.farmhousecheesemakers.com

Q. What causes milk to curdle, anyway?

A. Rennet. Rennet is a substance containing the enzyme ‘rennin’ which is taken from the stomach of the calf and when added to milk it curdles it, separating the solids from the liquid – for the calf to digest milk successfully, the milk it consumes needs to be separated into liquid and solids, i.e. curds and whey. This is simulated in the cheesemaking process.