Wie man einen Topf aus Kupfer macht | SWR Handwerkskunst

A pot of copper, a handmade piece of craftsmanship for hobby chefs. The red metal is still hand-pressed today. A pot for generations, almost indestructible if you know how to handle it. No other material conducts heat so quickly and can therefore also be perfectly regulated on the stove. It's just a nice material that you can work with excellently and a bit of the jewellery in the kitchen. It's just an object that you never put away. If you want to cook in a special way, you also need special materials. There is still a copper manufacture in Germany, which is still delivering tools. It works together with various specialists. Here in Ludwigsburg at the company Wahl, the pot body is produced in small series, in different sizes and shapes. Today there are jam pots on it. Mark Weyersberg sets the equipment for the metal business. Among other things, the so-called press form. Here they have specialised in hand-pressing, very old-fashioned, as it was 100 years ago. This makes manufacturing more flexible and therefore cheaper. It does have its necessity. The necessity is actually that hand-pressed copper takes much less setting time than a CNC machine. With 150 to 100 pieces, we have set up the machine in 20 minutes and can start immediately. The small number of pieces makes the craft attractive again. For the copper manufacture, Martin Mittermann presses once a month. Pressing pots by hand is not everyday for me, that is always very special. I like to do that because it just reminds me of the old days. With the copper pots, the special thing is that each part can be unique. There are certain basic measures that you have to adhere to, of course, but it is not so tightly tolerated and you already have a bit of leeway and can move more freely, I would say. The pure copper comes into the house as a sheet in a dimension of one to two metres. A valuable raw material, not just for cooking utensils. It is also installed in telephones, cars or computers and is an essential part of its function. Martin Mittermann needs one day for the pots he orders. The master in metal pressing first cuts his work material. He first cuts it into strips, each 40 centimetres wide. This is now a so-called table saw or impact saw. Simple, it's like a scissor, it's two knives that cut it off. And the sheet is just pushed through and comes to the stop at the back, which I set to measure before. And then it cuts down the strip by strip. One tonne of copper costs around 12,000 euros in the wholesale market, the trend is increasing. The plates are two millimetres thick, so as thick as a one-euro coin. A sheet of metal weighs around 37 kilograms. He now makes squares from the strips, also with the impact saw. From one sheet of metal he gets ten square pieces. Now we have to make our round cut, because we need sheet plates for press parts and pots. For this we have our electric circular saw here. So we now have a 40 centimetre square. That means I now have to set the stops to 40 centimetres. And we need a disc of 39 centimetres. Then I drive here to 39 centimetres. With us we normally speak of millimetres, 390 millimetres. And now I take the square and put it into the machine. I now have to lift the stop. Now you can see the impacts, how they come out. The circular saw tensions the sheet metal. It rotates. And then we have the two knives on the sides. They cut it through like a can opener, in principle. And then we get the disc. The rest of the square is collected. Every bit of it is reused. Copper is almost 100% recyclable. This means that Germany covers 50% of its demand on red gold. Each round later results in a pot. That's what the disc is called in the technical jargon. Next, the machine is prepared. The pressing bench is equipped with the supplied tools of the copper manufacturer. The 100 kg heavy press form is made of steel and serves as a blue pause for the marmalade pot. I'm now tightening our press form. For our press bench, on which we will then press the marmalade bowls. You could say that the press form is the negative contour. That is, the inside of our pot. The inside shape. With each press part, I have to adjust the machine individually. That means, I always have the shape. And then I have the hand rest, on which I then work with my tools. Of course, I have to adjust and position it individually every time. Depending on the size, distance and work area that I need. Now we need the so-called wooden template. This is a pre-setter that we clamp on the press bench. So that's screwed on here. This way I can fix my sheet metal. It is clamped firmly. It can't fall out. And the ground remains straight. When it's fixed, I can close it here. And clamp my sheet metal in there. Now I need my press tool. It consists of a so-called scissors. This is the lever with which I then dose the force. And the press rollers. This is the scissors. And a thicker press roller. I need a thicker one so that I don't weaken the material too much. And it ensures a smooth surface on the part due to the large area. So I'll start with this one. And to express the corner more sharply, I have a slightly thinner radius, a little smaller. I need it here to express the corner as sharply as it should be. Now I can clamp the sheet metal. First just roughly. Then I can align it to the press. Then I take my press roller. Hang it on and look. The working area for the beginning will also be enough for the end. Then I can put it aside. Then we fix the whole thing here with the wrench. Of course, you have to tighten it well so that it doesn't slip. I also have a screw here as a countermeasure that holds it in place. I tighten something. Now, as a rule, nothing can slip anymore. I'll straighten it out roughly. And I'll do the rest with the wood. And that's called a press rod. It only takes a few seconds to center the round. The disc should move evenly around the templates when pressing. Now I also need oil for lubricating. Because the roll is spinning, but there is still a certain friction due to the force. And that's why I lubricate the whole thing. When pressing, I now speed up the speed a little so that it can be worked cleanly. From the round, a span and seamless rolling will form in just a few minutes. Transforming a disc into a rolling body, that's the art of metal pressing. When pressing, it is important to always keep an even curve. If the sheet metal is still straight at the beginning, then you have to dose the pressure evenly at the beginning to shape the curve, which you then have to maintain in the further moves. If that doesn't fit, if the curve isn't right, then you get wrinkles quickly. The so-called folds are felt by Martin Wittermann in the material. They make the surface uneven. He gets the curve with the right pressing technique and a lot of feel for the copper. How the metal reacts, how much force he needs in his hands to shape it well, he gives the answers himself right after the first press. Even with almost 20 years of experience, every new workpiece is always a touch-up and a test. The first attempt was okay. I could have done it a little better and driven a little slower, so that the surface becomes finer and smoother. But the rough one was already very good. There are certain similarities to the potter's wheel. The material stretches when pressing. In the middle area, where I do the most, it becomes thinner and longer. The bottom is untouched, it is still 2 mm. From here it gets thinner to the middle and to the edge it is thicker again. It is simply because there the least is stretched out. When he has the twist out, he shapes jam pots in three-minute intervals. Copper and jam, proven for generations. And some hobby cooks swear on it, because the sweet bread on which it is made probably tastes more fruity, the color brightens and goes much faster than, for example, in a stainless steel pot. The pressing bench on which he forms them is from 1955, with the prediction of preservation. It states that the workpiece can still be worked on, although it does not correspond to today's work safety. Pressing on it requires a strong portion of muscle strength, especially with a 2 mm thick disc. You can feel the pressure, of course, I feel the resistance, the strength I need to shape it. If the sheet tends to fold, you can feel it, then there is a slight unrest, then you know, okay, now I can no longer go over it more strongly in the area. Now you have to get it a little softer again, and then you can press it further again. Reforming at room temperature is also called cold pressing. The soft metal tends to fold especially in the middle or become wavy, i.e. where the surface is processed and stretched the most. You can feel a lot with your hands, you are right on it, you notice it when you are standing on it, even if you don't hear it yet, but you can feel the resistance and you can also feel a certain unrest in the sheet. And of course, if you have the experience, you notice it all the more, and then you can already see how the sheet is standing, how it moves down. The second pot is also fold-free and well done. Folds or waves in the copper are not a defect, they just do more work. With heat, the metal presser gets them out again. I have a part here where the material structure has hardened a bit. This happens, for example, when you go over the material very often, when it comes to its limits, or when you were too coarse, it can also happen that waves come in. And now I'm just going to heat the material with a burner, soft-glue. The material structure is grid-shaped, let's say, and that narrows when it hardens. And when I heat it, the grid structure comes apart again and the material becomes soft and can be processed well. And that's what I achieve here with the burning, and then I can easily work out these unevenness in the material again. So now I have the part on this chamotte stone, which keeps the heat very well. And now I'm going to heat it from the inside with the burner. And in doing so, the material makes different color gradients through color stages, these are the temperature stages. And it goes from greenish, bluish to reddish at first. So when it turns reddish, dark red, then the material is soft. When it turns light red, then there is already the melting point, then you must not heat it so much. Five minutes under the flame of a burner is enough, and the grid structure of the copper is heated to around 500 ° C and thus again soft and supple. So the material was now glowed in between, so glowed red. When it gets cold, of course, it gets dark straight away, and then there is also this spark on the surface. You can see that right away. I'm going to take it now, of course, because it's very hot with the pliers, dive into the water, and in the water it cools down very quickly. Copper is very sensitive to temperature, and you can then touch it directly with your bare hand. I'm going to do that now. And now I would take it, I would maybe rub it off a bit beforehand with the pliers, lubricate it again and press it. So, the pot is now ready. This is just as good as the others. This dark one will be sanded later, the edge will still be turned, and then you can use it just as well as the others. So, the contour is now ready. Now it's about the edge processing, and the pot must have an outer diameter of 31.5 cm. We have our so-called cutting device on the bench, or it is also called lever support. There I have the option, I can clamp a lathe, and then I can use the lever to turn the pot to the desired size by turning the edge smaller. Cutting is a technical term among us metal printers. You can also just consider it as turning, like with a lathe, the same principle. With a lathe that cuts in a span, while it rotates, it cuts the part, i.e. the sheet metal, to the desired diameter. Now I have turned the part to size, and I have the sharp edges here. I will now simply pull off this ridge with this pull blade or hand straightener. You just pull it along the edges, and it makes a very light phase at the edge of the sheet metal, and so the whole thing becomes blunt. No one can get hurt, and the rest is fine-tuning. Now it is smooth. And the bowl is almost ready. Only the bottom is missing. It is still being made concave. With the deep-drawer press, it gets a slight curve inward, so that the pot bottom remains flat in the heat. For Martin Mittermann, this is the third and last act on the cookware. For the finishing, the rawlings go on to colleagues. They are specialized in the next steps on the pot. Germany's only copper manufacture is located in the Neckartal near Tübingen. In the side wing, in the castle of the Weidenburg, the founder of the manufacture is tinkering and marketing his dishes. Since 2009, Mark Weyersberg has specialized in copper. He is constantly trying new variants, because the metal is sensitive, but can also do a lot. It directs the heat immediately, so that it can be cooked precisely. A few seconds on the stove top are enough, and the pot and the content are hot. Someone who works with copper should already have a certain sense of the material. Concavity is essential in copper, because copper expands as a soft metal in heat. And because of this slight concavity, it can expand enough in heat, so that it is actually flat at the highest heat. And that is actually the prerequisite that you have good cooking results with copper. While chutney, polenta or egg white succeed in the uncoated copper pot, it is necessary to avoid acidic dishes. Under the microscope, he examines other materials. Copper in pure form is mainly used for sweet dishes. Copper is also very relevant when cooking jam, because the copper ions react with the fruit, the gelation process is improved, and on the other hand, the strongly decaying effect of copper. With other ingredients, the reddish metal acts toxic. If I, for example, would react with goulash, i.e. with a piece of meat, the copper ions would contribute that the meat tastes like copper. In this case, the copper ions have a rather negative effect. So we then decided with the most modern German surface technology to coat very different surfaces on the copper, so that there is no immediate reaction with the copper, but intermediate reactions that have a special anti-adhesion effect, which have very good roasting properties, or simply the function that the pot becomes induction-capable, because it is not induction-capable from copper per saldo. Ceramic, for example, is a good surface for the anti-adhesion effect. In order for the copper to perform on an induction stove, it binds a so-called ferromagnetic element. This makes the pot magnetic. Compared to pure stainless steel, copper is 20 times faster. It heats up to 200 ° C in a few seconds. This is not achieved by any other material in such a short time. Cooking with copper also saves energy. Here you can see the whitish discoloration on the left. This is a sign that the water is seeding in the copper pot. Slow seed traces in the stainless steel pot. However, the handle on the copperware also heats up quickly. Sustainable waste management creates pots. If you take the nostalgic handles, the brass handles, bronze handles or cast iron handles, no matter which handle you choose, it will always be warm, because copper conducts so extremely. Because of the heat conversion, the heat reaches everywhere and also in the handle. Speaking of handles, they are still missing from the jam pot. Mark Weyersberg puts the material back here. Now Jan Schneider takes over from the Hebisch company in Tirol. For the jam bowl, we use brass handles. These are our largest handles. They are welded to the jam bowl as side handles. But before welding, the grinding is done first. Due to the grinding dust on the copper, you get very dirty and the power goes in everywhere. To protect against this, I prefer to wear a suit. Jan Schneider grinds on a specially converted press bench. We have a vacuum pump for this. A pneumatic hose holds the pot in the vacuum and you can work anywhere on the pot without having to clamp. The clamping form on the press bench is made of plastic and acts like a suction cup. The 50-year-old needs two tools on the press bench. Grinding cloth and a compressed air grinder. This removes a total of 0.1 mm from the copper surface. So that the grinding cloth doesn't add up, we clean it with petroleum. For the entire grinding process, it takes between 2 and 5 minutes per pot. Now I grind the surface with the air grinder so that I can remove the grinding cloth better. Due to the production of transport, we always have small grooves or scratches in it and we have to remove them completely. I now take different grinding cloth grains, once 40 grams. The coarser the grain, the more I can remove. For example, if I have grooves in it, they are between 0.05 and 0.1 mm deep. That's why I take the coarser grain, so that it is easier to remove. It doesn't look nice, so I have to rework it with a finer grain. What looks so light and refined is also a combination of technology and a sense for the material. As soon as I get to the head surface it has a braking force and I want to pull it. That's why I have to hold it back with the other hand, because otherwise the pressure will pull me. That's why you always have to lift it with both hands to reduce the pressure. Because of the friction, it gets extremely hot. If I wanted to work at high speed, I would burn my hands. That's why I start with a slow speed and at the end with a high speed. There is not so much friction, so I work at a faster speed. You have to build up pressure, but you don't feel it with your fingertips. They are always on the head, but physically it is exhausting. When I have sanded everything, I take the oil and oil the surface so that it does not oxidize. Without oil, the copper would react with the oxygen and moisture from the air immediately. The consequences? A run-on pot. The oil forms a protective film. When Jan Schneider changes the tensile shape, the outside is ready. It goes on to the inside of the pot. The same grinding and protection procedure is carried out. The longer it stays in the air, depending on the humidity, it can be. After two days, the material is pretty worn out. Then it is very time-consuming to remove it. That's why we always want them to be ready as soon as possible. Then it's time to weld the point. From now on, gloves are mandatory. I have to put them on now so that I don't oxidize the pots. But if I put them on without gloves, it may be that after two days they start to get green spots. I have an angle of attack. With this angle of attack, I can mark the middle of the pot so that I can put on two side handles so that they are exactly opposite. I put the pot with the marked direction to me so that I can put my device on it. When I make it myself, it's practically the same handle that I then reassemble with a larger drill. I put it exactly in the middle with the marking. Then I can put the first bolt and that's how it's welded together. The bolt has a small leaf at the front, which is turned to it. As the current comes on it, it explodes and then both surfaces are liquidized and welded together. The rust also starts to oxidize immediately because the oil layer, which is applied as protection, is then evaporated. Because of that, we have to wet it again with oil so that you don't notice it immediately, but after a day or two it will oxidize. After welding, it's over for today. Tomorrow it's the turn of the handles. The trained tool maker applies the handles with the help of the so-called workshop press. The stamp on top has such a curve. And through this curve, the handle and the bolt are pressed together so that they don't come apart. You can imagine it like a mushroom. We put a mushroom on top with this curve so that the handle can no longer come loose through the bolt. Handles like bolts are made of brass, a copper-zinc compound. With 300 kilograms, the machine presses the two individual parts together. In the technical jargon, this process is called rounding or pressing. The handles are on and carry a load of 10 kilograms. Three out of four steps are done. The last one starts with the handles again. Some of them sit crookedly on the pot. This happens when rounding. With the measurement unit Pi times thumb, they can be easily adjusted again. It's a manual job. It has to look nice by eye. I don't care about the dimensions. This pressure point is created because the copper is softer than the brass. Copper gives in immediately. It can't be prevented. Don't prevent it, but the pressure marks can be hidden with fleece. To make the marmalade pots shine in the copper manufacture, there is one last oiling. A pot like this is worth almost 300 euros. You can still grease the metal if you want, but you don't have to, if you don't mind the worn surface. Here they are safe again. The pot is packed airtight at the end. The copper dishes are distributed exclusively via the specialist store. Cooking in copper requires a manual, e.g. never fry food in it hot or cook for a long time over high heat. If I know which rules I have to follow, that I never add too much heat, and that I'm more enthusiastic, then I have something for life and a wonderful heirloom for several generations. Another rule is, for example, to always heat the pot with content. Copper is a bit like the Formula 1 car in the kitchen. And since it's so fast, you should always have something in the pot before you heat it up, so that the bottom does not plop due to the spontaneous heat development. Or stay on the pot while cooking. Now I put the sugar in. Now 200 grams of sugar is mixed with natural apple extract. And from now on it is important that you stay stirring. Otherwise the sugar caramelizes on the bottom. What I would not recommend with copper is to cook for a long time, over 24 hours. What should you do in stainless steel vessels and only cook the final solidification process in copper? Because otherwise too many copper ions enrich the fruit and then a too high concentration of copper is created in the food. You can slowly notice how the gelation is initiated. Now we can do the so-called gelation test. Then I basically check the consistency. And if the fruit moves slightly back and forth when it is slightly cooled, then it is gelated. You can already see that it becomes much more viscous. I would give it another minute and then we have reached the gelation process. In addition, the short cooking times. Within just 5 minutes, the fruit is gelated to the jam on the gas stove. Tasty results in the copper pot are also a question of the right temperatures. With moderate heat, it can be cooked in advance and quickly. In the kitchen, the pots made of the special metal are now versatile, because the manufacturer has coated the surface appropriately. It has partly packed the reddish metal into a steel alloy. This makes it induction-capable and equally resistant to temperatures up to 200 ° C. These are necessary for crispy roasts and a crispy skin. As is well known, taste can be disputed, but not the ability of copper. It conducts heat quickly, precisely and seems to be germ-free. In addition, the piece of property remains for generations. A diva in terms of care. Copper is a living material. Deoxidation is a completely natural process. It can oxidize in all rainbow colors due to the development of heat in connection with moisture and oxygen. But it has no functional limitations. On the contrary, it gives the pot a wonderful patina. It changes visually, but there are no limitations in terms of use. Are you fascinated by craftsmanship just like us? 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