Things Worth Living For: Salt-fired German Beer Humpens

Here's a fluffy, Feel-Good, non-confrontational post to lull you into the weekend, it's about mugs.

I honestly can't remember how I ended up buying my first German beer stein. It might have been after going down a deep, dark rabbit hole about traditional European high salt fired ceramics. I do, after all, have a university degree in the ceramic arts. Not the tiddly-winks basket weaving kind of a degree, but rather one that involved, among other things, building kilns from dumpster scraps, welding, formulating experimental purpose specific clay bodies, mold building, slip casting and using the ashes of specific hardwood trees to replicate a 2000 year old Chinese glaze. An engineering/chemistry/materials science/playing-with-fire degree or a sort that I abandoned in the end to make giant color field paintings, but I digress.

Firstly, what makes these mugs interesting, to me anyway, is that the way they are made. They begin as a slug of grey clay that is then swaged into the distinctive sort of bullet shape inside a die with the help of a plunger being pressed in at many thousands of PSI. (Ironically, this is exactly how the copper jackets of rifle and pistol bullets are made so the bullet shape may not be a coincidence.) The newly formed mug body is then trimmed and cleaned up by hand using a metal tool like a lemon zester and a damp natural sponge. On the mug on the right you can actually see the remains of the sponge mark at the bottom in the center, which I find un-endingly charming.

Next they're taken to a room where they sit and dry out for a day or two (this step cannot be rushed and, in fact, should be as slow as possible to prevent the clay from cracking because of the differential between the density of mechanical water in the thicker base versus the thinner lip. If these forces become to extreme you will have a shearing effect that will form a nearly perfect circular stress-riser around the circumference of the mug and the top 3/4s of the mug will just pop off. This is avoided by slowing the drying process with high humidity and giving the clay time to equalize. A process not unlike the salt equilibrium period when you are curing prosciutto, jamon serrano or country hams. Looks like that degree paid off after all...)

After drying to "leather hard" they are taken to an actual human who forms and attaches the handle by hand. And I mean "by hand". See that handle shape? it was formed by squeezing and drawing a piece of clay between the inside of the thumb and the knuckle of the forefinger knuckle area of the palm of some German guy. It's literally the outline of his hand. Once the handle is drawn it is then attached by smooshing the clay of the handle into the clay of the mug. Again, check the top of the mug on the right. You can see the thumb marks! Again, very charming but also very functional as the portion of your hand, when gripping the mug, is exactly the same portion of hand used to form the handle!

Ergonomics, people! These things, despite being fairly heavy and full of a half liter of beer (that's a pint), feel weirdly light in the hand because of this thoughtful and ingenious process.

A vision of the future me

Lastly, the mugs are taken to a series of two kilns. One is the low temperature bisque firing that removes all the mechanical water (as opposed to the water that is bonded, chemically) from the clay, pretty boring, and the second is the high salt firing, where things get exciting.

So once the kiln reaches around Cone 9 (2300' f), the neighborhood where the various minerals in the clay begin to vitrify (or fuse together to form, essentially, artificial stone) there is a massive injection of rock salt mixed with a bit of water through ports in the sides of the kiln. Because of the high temperatures inside the kiln the salt explodes and atomizes, turning into a vapor that coats the mugs. Then something really interesting happens: everywhere the salt vapor touches, the clay becomes molten in a thin layer of the outside. Yeah, like fucking LAVA, molten. The salt acts as a Flux that chemically lowers the melting point of the surface of the clay. This forms the glaze, or glassy surface, of the mug making it suitable to put beer or in my case, herbal tea in. Without the glaze the stoneware would be porous allowing millions of little crevices for bacteria to hang out and be gross in, an undesirable trait in a beer stein.

Well, that's it, your Friday beer themed fluff post has been served. Have a great weekend.

Yes, they come in Liters too.