Bean compartment capacity
The maximum number of coffee beans that the grinder can hold and process at one time, without "refilling". Note that we are talking about the maximum capacity — a smaller amount of coffee can be loaded into the grinder.
The standard portion of coffee per cup is 5-7 g, and the capacity of a pack of coffee is 100 g. Accordingly, it is worth choosing a model according to capacity, taking into account how much coffee you need to grind at a time. For domestic use, a capacity of 100-200 g is considered quite sufficient, but in professional models designed for coffee shops, bars, etc., this value can reach 1.5 kg or even more. There are coffee grinders that allow you to grind only part of the coffee loaded into them.
Power
The maximum power consumed by the device during operation. In coffee grinders, productivity is primarily associated with this parameter: the higher the power, the faster the grinder handles with the task (ceteris paribus). The suitability of the coffee grinder for working with solid products also depends on the power — more powerful models are better suited for these purposes.
Buying powerful models for everyday use in life is hardly justified: they are expensive, and the time savings are small. But in the professional sphere (for example, in a cafe), where the speed of preparation is crucial, high-power coffee grinders are very useful.
Number of grinding levels
The number of grinding levels provided in the coffee grinder.
For different cases may require different degrees of grind, see “Adjusting the grind” for more on this. The same parameter determines how many fixed settings are provided in the coffee grinder. The more of them, the wider the capabilities of this device, the more accurately you can choose the option for a particular situation.
Note that this characteristic is given only for models with millstones (see "Grinding system") — it is not relevant for knife devices. In the most advanced models, the number of grinding degrees can be in the dozens.
The volume of the compartment for ground coffee
The capacity of the ground coffee compartment provided in the coffee grinder.
About such a compartment, see above. On the one hand, capacity affects the amount of coffee that can be ground in one go before filling the compartment, on the other hand, on the dimensions of the compartment and, accordingly, the entire device. With this in mind, in most models this figure is from 100 to 200 g — this is the optimal value in terms by the ratio of capacity and size. At the same time, for domestic use, you can choose a model with a smaller capacity; and coffee grinders with capacious tanks are convenient, for example, for specialty stores where coffee beans can be ground in the presence of a buyer.