As with whole spices, coffee beans contain volatile flavours that literally vanish into thin air soon after they're ground. So, no matter how you make your coffee, it's better to buy whole beans and grind them as you go.

A mill also gives you a chance to experiment with different varieties and blends of bean, in order to discover which works best for your favourite brewing method.

There are two types of electric mill: one fitted with blades, the other with grinding plates - sometimes called a burr mill.

The blade mill suits most people's budget. It's simple to use: you control the consistency of grind by pressing the switch for shorter or longer bursts.

Keen cooks might want two of these: one for coffee and one for spices. You can also use it to quickly chop nuts or make breadcrumbs.

If you have just one mill, clean it thoroughly between different ingredients by blitzing a bit of white bread in it. You don't want your coffee flavoured with garam masala! (And remember that used coffee grounds can go straight on your compost heap and they're also thought to deter slugs.)

Serious coffee connoisseurs will prefer the precision of the burr mill. Depending on the model, these mills have between 10 and 40 different grind settings, one of which will be just right for a particular type of brew.

Perfection comes at a price however: a burr mill can cost well over £100. They also tend to be quite noisy and can take up a fair amount of space.