Here is a quick guide to the different types for grinders available and their uses and limitations.
A Blade grinder is basically a small blender, a spinning blade cuts up the coffee beans, the longer you grind for the finer the coffee. Blade grinders are ok for french press but are no use for espresso as there is no consistency of grind, and an espresso machine loves consistency!
Hand burr grinders
A burr grinder is basically a pepper/salt grinder but much more accurate. It has two burrs which can be brought closer together to achieve a finer grind. the advantages of a burr grinder is that it gives a very uniform particle (grind) size and as less heat is produced it affects the oils coffee less maintaining the flavour. A hand burr grinder is a great way to get started if you want to grind for espresso, just bear in ming it does take some time to grind enough coffee for a double shot! You can pick up a hand grinder capable for riding for espresso for around £20-£40 the Hario mini mill is a good starting point and has ceramic burrs.
A motorised burr grinder is what all coffee shops use, there are hundreds to choose from and you will need a motorised Burr grinder if you want to make more than a cup a day. They vary in size, quality, functions and ultimately grind consistancy. We will be adding Coffee grinder reviews to the grind&brew website over the coming months to help you make the decision.