Steel, titanium or ceramic? Differences in grinding stones

Well-ground coffee beans are the basis for espresso and filter coffee. It is this good grind that is the proof of the grinder's quality. Inside such grinders are grinding stones. It is the most important part of the grinders. Between them, the roasted coffee beans are crushed so that they can be further used in the preparation of coffee. For making coffee by any method, the uniformity of the ground coffee particles - the consistency of the grind - is important. A proper grind is a consistent grind of a certain degree of coarseness, which is determined by the method and style of coffee preparation.

The size of the stones is determined by the space and technical design of a particular type of grinder. Smaller grinding stones are common in smaller and cheaper types of household grinders. The larger surface area of the stones means that such a grinder can cope with a higher load of traffic without negatively affecting the grinding and the coffee inside the grinder.

TWO TYPES OF GRINDING STONES

The differences in grinding quality between flat and conical stones are almost minimal. Conicalgrinding stones havethe advantage of alonger sharpening time than flat stones. On the other hand, conical grinding stones have to be replaced, whereas flat stones can be reground. Often the choice of the type of stones to be produced in a particular company is derived from the tradition of production of that type. However, conical stones are more space-saving due to the technology of assembling the stones 'into each other' and also the coffee is supposed tomove better inside the grinding mechanism, which is predetermined by the slant of the stones.

The type and size of the stones are factors that mainly influence the technical design of the grinder itself, its size and recommended use. You can grind quality coffee in flat or conical stones of any size, as long as they are well seated and you use the grinder in accordance with its characteristics.

DIFFERENCES IN MATERIALS

Thegrinding result is then most influenced by the material from which thegrinding stones are made. Ceramic or metal is used to make the grinding stones . Each of these materials has its own specific characteristicsthat determine the best way to use them and which should be takeninto account when choosing a grinder .

CERAMIC GRINDING STONES

Ceramic grinding stones are great for hand grinders. They are also often used in them. Ceramic grinding stones are popular in hand grinders, for example by the Japanese company Hario, whose products are so popular among baristas. An excellent candidate for a reliable hand grinder is the Hario Skerton Pro. Its ceramic stones grind coffee gently and if you prevent damage, for example by impact, you will be perfectly happy with it for a long time.

CERAMIC GRINDING STONES

Positives:

the sharpness of the stones
long service life
heat conduction
fuller coffee body

Negatives:

fragility of the material
lower durability
need for careful grinding

METAL GRINDING STONES

Compared to ceramic grinding stones, metal ones have the undeniable advantage of the durability of the material itself. The hard metal can withstand rough handling, but its durability and the sharpness of the teeth on the grinding stones weaken. It is necessary to keep an eye on their sharpness and, depending on the amount of coffee ground, send the grinder to a service centre for regrinding or replacement of worn grinding stones.

METAL GRINDING STONES

Positives:

high durability
handles heavy loads
suitable for catering and industrial use
Variations according to metal type

Negatives:

heating and heat retention in the metal stones affect the coffee inside the grinder
keep an eye on wear and tear and re-sharpen or replace the stones

STEEL COMPOSITION AND COFFEE TASTE

The method of hardening and refinement of the steel from which the stones are made affects the resulting taste of coffee. The companies that manufacture grinding stones for coffee grinders monitor the quality and composition of the materials used to make them. Mahlköniggrinders are particularly popular with the best professional baristas, and the exact material composition of the grinding stones is also a company secret when producing these grinders.

DURABLE GRINDING WITH TITANIUM STONES

Longer service life can be achieved with metal grinding stones made of titanium. These are basically steel grinding stones. They are coated with titanium nitride. You can recognise them at first glance thanks to their golden colour. In addition to their golden appearance , titanium stones give you up to 6 times longer life than conventional steel stones. You will appreciate this feature especially in grinders in a busy café.

Not only the lifetime and overall durability of titanium stones is higher. Therefore, they can also cope very well with lighter roast coffees. Roasting reduces the density of the coffee bean. The darker the roast, the more fragile the coffee. On the other hand, coffee that is roasted lighter is more interesting in terms of flavour, can be prepared to its full potential, including the subtlest flavour nuances and aromas, and is undoubtedly healthier, but such light-roasted beans have a higher density. They are therefore harder for the grinder to grind. This increases the stress on the grinding stones and reduces their life. The use of titanium stones will help solve this problem.

STONE SHARPNESS AND GRINDING QUALITY

The material used to make the stones therefore has a major influence on their sharpness and durability. The basis of good coffee - a consistent grind - can only be achieved with sharp stones. New grinders with freshly sharpened stones may therefore seem the most advantageous for making the best coffee. With these new pieces, however, you have to carefully watch and readjust the coarseness of the grind before the grinder gets "stuck".

The life of the grinding stones is in the hundreds of kilograms for professional grinders. For manual ones, it will be tens of kilograms due to the smaller size of the stones, which wear out. If the grinder grinds inconsistently and the coffee changes flavour, we recommend replacing the stones.

REGULAR CARE OF THE GRINDER

You can ensure a longer life for the stones and the grinder by proper and regular care. Cleanyour grinder every day to prevent the build-up of old coffee. This would get into the batch of newly ground coffee during the next grind and adversely affect its quality and taste. Uncleaned grinder builds up deposits which, over time, develop mould and bacteria. Coffee from a grinder that is not cleaned endangers the health of all those who drink it.

Supplementdaily mechanical cleaning, preferably using a brush and vacuum cleaner, with regular thorough cleaning of the grinding unit using special chemicals. This is sold in the form of grinder tablets. The tablets are washed to rid the grinder of oils from the roasted coffee. The old oils tend to go rancid and apart from the unpleasant smell and taste in the coffee, such coffee becomes unhealthy.