When shopping, you can choose between Melitta®'s natural brown or white filter papers®. There is no difference in terms of filtering properties between brown and white filter paper from Melitta®.
To ensure optimum coffee preparation, the filter paper must be moulded to fit the shape of the filter exactly. This is done by folding over the two crimped edges. The filter paper then nestles perfectly with the edge of the filter and sits deep in the filter insert. This good fit means that the paper will not fold in on itself during the brewing process.
When filter papers were in their infancy, there were no coffee makers - in those days, coffee was brewed by hand. To do this, filters and filter paper sizes 100, 102® etc. - depending on the number of cups required - had to have water poured over them several times over. It was only possible to estimate how much coffee would then finally end up in the pot.
During the 1960s, Melitta® invented the "1x filters system". Depending on the size selected, only "1x" amount of water needed to be poured over the coffee with these new filters and filter papers (i.e. 1x2 filter paper poured over 1x = 2 cups of coffee, 1x4® filter paper poured over 1x = 4 cups, etc.) and offered the correct number of cups - a boon for coffee lovers. For a long time, both the 100x series and the 1x series existed in parallel, since households still had filter bodies for both types.
Nowadays, virtually all machines use "1x4®" filter papers, because they offer the perfect size for the quantity of water and coffee required in the main 8-10-cup appliance sector.
Filter paper has two seams that are not glued together, but are rather crimped together. In other words, it is this crimping that keeps the filter paper intact.
All in all, there are seven different sizes of filter paper available in shops. The various sizes have arisen over time for various reasons (see: "What exactly does "1x4®" mean in terms of filter paper?").
Indications on the correct size of filter paper can be found in the operating instructions for your coffee machine, or on the filter itself. The right size is particularly important, since otherwise there is a risk of the filter tearing or folding over.
Brown and white Melitta® filter paper is manufactured in an eco-friendly process and can be disposed of as bio-waste. There is just a small difference in the manufacturing process: white coffe filters are bleached using environmentally-friendly oxygen (not chlorine), while brown filter paper is not bleached.
"Strong" filter papers® from Melitta® have a special, dense-pored paper structure that extends the coffee's brewing time. In the lower section, the special coffee filters are made from stiff, less porous filter paper ("pre-brewing zone"). During brewing, the water thus remains in the filter for longer and can mingle more intensively with the coffee powder. The coffee can develop its full aroma.
"Mild" filter papers® from Melitta® shorten the brewing time thanks to their wide-pored paper structure. This makes the coffee aroma particularly fine.