MATERIAL & COATING
Non-stick, Teflon®, ceramic, aluminium
Cookware is much more complex than it appears at first glance. There are many factors that influence the quality and service life of pots and pans! What makes the difference are not only the materials we use, but also our expertise and experience. All this, combined with our high quality standards, defines each one of our products. Over its long corporate history, BERNDES has not only acquired know-how, but also developed many innovations. That is why BERNDES is today a leading specialist in non-stick-coated cast aluminium cookware.
Before you buy a new item of cookware, it is a good idea to find out a few facts so that you can choose the best products for your needs! Here is some more detailed information to help you make your decision.
The raw materials for cookware
Over the ages, humankind has used many different materials for cookware. Each material has different requirements and properties. Apart from clay vessels, copper kettles or uncoated aluminium cookware, above all cast steel pots and pans have been used in more recent human history. Ever higher requirements relating to cooking and cleaning triggered the development of stainless steel, aluminium and cast aluminium cookware as well as non-stick coatings. Today, BERNDES focuses on cookware made of stainless steel, aluminium and cast aluminium.
The starting point for stainless steel products is a stainless steel blank (flat disc). This is greased, placed in a hydraulic drawing press and shaped over a so-called deep-drawing die. Next, the edge of the raw body is punched so that the finished cookware has a clean pouring edge. For better heat conduction, stainless steel bodies are fitted with a capsule base. Aluminium is integrated in the capsule base to optimise the absorption and transfer of heat.
A circular aluminium disc (blank) is used for the pan or frying pan. BERNDES uses discs between 3 and 5 mm thick. We use two different production methods and exclusively process aluminium alloys approved for contact with food.
Similar to stainless steel processing, the aluminium blank is greased and placed into a hydraulic drawing press where it is shaped over a deep-drawing die. Depending on the product size and blank thickness, a weight of up to 200 tons is applied for this forming process. The advantage of deep-drawn parts is an even thickness of base and walls. This ensures good heat conductivity.
Impressing die forging (also called closed-die forging)
Again, this involves forming an aluminium disc. The press works with two dies (top and bottom tools) which it slams together, applying pressing forces of up to 4,000 tons. The finished cookware produced in this way has an almost identical appearance to cast parts (see Cast aluminium), however, the two types differ in heat conductivity and heat retention.
Aluminium has only been used for about 200 years. That may seem a long time, but compared to the above materials it is a very young addition! What makes cast aluminium ideal for cookware is its optimal heat conductivity und heat retention as well as its light weight. The casting process involves injecting liquid aluminium into a pre-shaped casting mould under vacuum. This ensures there are no air bubbles. The advantage of this process is that even complex shapes are possible which can not be made from aluminium blanks, e.g. frying pans with grilling ridges, rectangular shapes or deep casseroles with cast-on handles. The result is perfect material distribution for every product.
There are distinct advantages of coated cookware which we would like to explain to you below. We also want to explain the clear differences in the properties. You should choose the right coating for the intended purpose, e.g. a high non-stick effect for fat-free cooking of pancakes and other egg-based dishes.
BERNDES usually uses strong triple-layer coatings comprising the following layers: primer, middle layer and top layer. Non-stick coating is based on a plastic, more precisely polytetrafluorethylene (PTFE). Since its discovery about 40 years ago, there have been no signs of health risks from its processing or use. This PTFE can be used up to a maximum sustained temperature of 260 °C/500 °F. That's much too hot for cooking foods, and most fats and oils burn off well below this temperature.
We won't go into PFOA or PFOS because we don't use either of these hazardous substances in our coatings.
After the coating is applied to the cookware, it is fused on in a sintering furnace at approx. 430 °C/806°F. This process must be very precise because the temperature control in the furnace is a decisive factor for the quality of the finished article. First, slow heating ensures the water in the coating evaporates before the start of the high-temperature drying and hardening process. The properties of the middle and top layers (hardness and non-stick effect) combine during the drying process. In this way, BERNDES guarantees:
- High non-stick properties
- Long life with correct care
- High and lasting colour-fastness
- Hardwearing quality in practical use
This kind of coating has only been in use for a few years and is currently very popular because it can be used for white or coloured surfaces. Like PFTE non-stick coatings, this type of coating is also safe to health. In contrast to non-stick coating, ceramic coating is extremely hard and scratch-resistant. However, similar to enamel, the hard coating is vulnerable to impacts, especially on the edges of pots and pans! If you use an induction or gas cooker, you will benefit from the high heat-resistance. Ceramic coatings usually consist of several components blended together. They are burned on at a temperature of 220 °C/428 °F, which triggers a chemical process that produces the final hardness. You should know the following about ceramic-coated cookware from BERNDES:
- The production process produces extremely hard and scratch-resistant coating and non-stick properties, however these decline over time and are not comparable with the non-stick properties of a PTFE coating.
- CAUTION: Although other manufacturers suggest in their marketing that you can fry fat-free in ceramic-coated cookware, this is not true. Many customers believe these claims and have been disappointed.
The sustained heat resistance is much higher at 400 °C/752 F, and overheating does not cause any risk to health. However, this property is actually irrelevant because nobody should work with temperatures above 200 °C/392 °F when most oils and fats have already burned away.
- The sustained heat resistance is much higher at 400 °C/752 F, and overheating does not cause any risk to health. However, this property is actually irrelevant because nobody should work with temperatures above 200 °C/392 °F when most oils and fats have already burned away.
- The BERNDES ceramic coating is ideal for searing or browning e.g. fried potatoes, steaks, turkey strips and other meat
- Easy to clean
- No PFOA is used in the manufacturing process
- Almost all colours are possible
BERNDES also supplies non-coated cookware with stainless steel as the basic material, which is also safe to health. There are no limits to its heat resistance, similar to ceramic coatings. However, high temperatures are not really useful because oils and fat burn away from temperatures of 210-220 °C/410-428 °F. Stainless steel itself is a poor heat conductor. That's why stainless steel cookware often features a capsule base with a copper or aluminium plate inside (see Cookware bases). Stainless steel does not come with non-stick properties, so food can burn on at high temperatures and is difficult to clean off afterwards. For this reason, when you use stainless steel cookware, always add oil or fat for frying or water for boiling. This prevents the food from sticking. It is important to add salt to the water only when it is boiling, otherwise salt deposited on the bottom of the pan can cause pitting of the stainless steel surface. Any blue stains may be caused by minerals in the food and are completely safe. You can remove them with a little citric acid.
Different bases for different cooker types
Cookware needs to function on as many types of cooker as possible. Induction cookers, which are becoming more and more popular, are a special case. All our products are suitable for electric, gas and glass-ceramic hobs. For induction cookers, the base must have a ferro-magnetic layer. We always indicate on our products what types of cooker they are suitable for.
What's special about this base is that after it has been ground flat it receives a light texturing that allows it to expand towards the hob plate when hot so it sits on the hob plate perfectly flat. No energy is wasted heating air and the cookware rests firmly on the cooker. Another advantage is that the base heats up evenly, something which is incidentally true of all BERNDES cookware! These bases are regularly tested in our lab according to DIN 44 094 and DIN EN 12 983-1. This involves heating the empty product to 200 °C/392 °F then immersing it in cold water up to 50 times. The base must retain its shape without any deformation!
Induction capsule base
This kind of base is used very commonly for stainless steel cookware. Today, pan bodies are usually made of chrome-nickel-steel and the bases consist of ferritic stainless steel that reacts to magnetic force and is therefore suitable for induction cookers. Stainless steel itself is a poor heat conductor. That is why a material with good heat conducting qualities such as aluminium or copper is integrated in the base.
Pressed induction bases
A magnetisable plate is pressed onto the aluminium body on a press applying a force of up to 3,000 tons. The energy applied here fuses the two materials together. To ensure a long service life, we advise you not to use a dishwasher because aggressive cleaning agents wash out the aluminium and the plate eventually comes loose. Please also note our care instructions
In 2009 we upgraded the cast aluminium products in our PROFESSIONAL series with a special premium induction base featuring a unique non-distorting, smooth and very hard surface. In a cold gas injection process, we spray ferritic stainless steel powder at high kinetic force onto the aluminium base. This micro-welds the fine particles to the base. That's why the bases in the PROFESSIONAL series are extremely durable and do not scratch the cooker surface. Furthermore, these products are suitable for all types of cooker!