Air holes

Air holes in handles, grips and lids

Porcelain items with a solid handles, grips and knob or even lid knobs usually have a small, barely noticeable hole. The air which is created in a hollow chamber of the porcelain is removed through such an opening during the firing process. Without this air outlet opening it is not possible to produce hollow parts in porcelain. There are suppliers who subsequently close such openings by using plastics, silicones or other foreign materials. However, we at Holst Porzellan have not yet found any such possibility that fully complies with the Foodstuffs Commodities Ordinance. Apart from this, ceramic bodies and plastics are subject to very different corrosion behaviour.

In earlier times, today only with very expensive white goods or decorated porcelain, such openings are subsequently closed with porcelain slurry and fired a second time. In this process, the risk of deformation of the knob causes further rejects. If the handle were to be produced without a hole, it would have to be made virtually solid - which is also not possible from a production point of view. In the end it would be so heavy that it would simply fall off during the firing process.

We at Holst Porzellan therefore make every effort to make this "must-hole" as discreetly as possible and to keep it as small as possible. Apart from the purely optical perception, the hole should be so small that no solid foreign matter can penetrate. Any residual water that may accumulate in small quantities in the hollow body during rinsing should not run into the contact surface of food and drink.

For this reason, such an opening is not regarded as a production fault, but is rather a necessity due to the nature of the goods. Incidentally, the penetration of rinsing water can be reduced by setting the body at an angle and thus not exposing it directly to the rinsing nozzles. Any remaining residual water dries or evaporates in the natural process. If unwanted residual moisture should escape during commercial use - e.g. in the bumper-to-bumper business - we recommend placing the porcelain article in the microwave for a few seconds after rinsing or before refilling.