How do I select the correct coffee grinder?

A coffee grinder may well be the single most important piece of equipment you are going to buy in your endeavours to making great coffee. An excellent grinder can often compensate for a lesser espresso machine but even the best espresso machine cannot compensate adequately for a poor quality grinder. 

It is always important to have a good grinder but is absolutely essential when making espresso. Due to the fact that an espresso is such a concentrated beverage any faults in the process are magnified and are significantly more noticeable than for example in filter or plunger coffee.

So which grinder do I buy? It is a generally accepted standard that you should buy the very best grinder that you can just not afford. I guess what we are saying stretch yourself as far as you can when buying a grinder for espresso.

Different types of grinders:

The two most common and significantly different types of grinders are Conical Burr (LH Image) grinders and flat burr(RH Image) grinders. (Blade grinders also known as spice grinders is not considered to be an option)

Conical Burr Grinders.

Conical burr grinders tend be quieter, grind cooler and have less grind retention that flat burr grinders. They are often more compact than flat burr grinders.

Conical burr grinders are often used in automatic coffee machines(due to their compact size) and also in lower to mid-range home grinders. This not always true but is generally the case. The Baratza Sette grinder is one of the exceptions being a fairly expensive home grinder with conical burrs.

Good quality shop grinders with conical burr sets tend to be much more expensive than comparative flat burr grinders. 

Flat Burr grinders.

These grinders tend to be more noisy than their conical counterparts, often have more grind retention and heat up quicker. They do normally have better grind uniformity than conical burrs. Large flat burr grinders tend to be less pricey than the equivalent conical burr models. Flat burr grinders are by far the most common type found in coffee shops.

Flat burr grinders can range from very cheap (and fairly nasty) to very expensive high end shop grinders. You can buy flat burr home grinders from as little as R1300 to R15 000 and maybe even more. Shop grinders can be in excess of R40 000 depending on size and features(grind by time, grind by weight, built in cooling fans, temperature control , motor power, burr size etc) all play a big roll in the final price of the grinder.

Doser vs. On-demand grinders.

A doser grinder typically has a fairly large chamber mounted to the front of the grinder into which the ground coffee is dispensed as it exists the grinding chamber. The coffee will then typically stay in the dosing chamber until it is required. The coffee is dispensed by pulling on the dosing lever which will the dispense a fixed(but normally adjustable) volume of coffee.

On-demand grinders does not have a dosing chamber and the coffee is dispensed directly into the portafilter (or other container) as it exists the grinding chamber.

 On demand grinders are increasing in popularity due to the better accuracy and the “always freshly ground” benefit. High end On-demand grinders are now very fast which also helps to improve  the speed delivery of beverages.

The latest improvement available from some manufacturers is the “grind by weight” function. Most electronic on-demand grinders use grind time to deliver the correct dose of coffee. The disadvantage of this is that you have to reprogram the grinder every time the grind coarseness is adjusted. Grind retention can also affect the accuracy of the dose. The “grind by weight” function eliminates these problems(at a cost!).

See the table below for some grinders to consider when shopping for a grinder.