Sharpen knives correctly - Instructions for sharpening & grinding
- Material and preparation
- Costs and prices at a glance
- Waterstone - fine cut
- Belgian chunks - high-quality grindstone
- Sharpening steel - temporary solution for in between
- Sharp and hard - high quality knives
- Grind knives - the manual
- Great guide as a video
Whether tomato, steak or the delicious fresh bread, they all want to be divided professionally. If the tomato has fallen victim to a blunt knife, it is only good for the soup. A steak that you can not cut also causes just frustration. So that you always have a sharp knife for the different treats, here we show you how to properly sharpen knives.
There are quick solutions and good solutions. This is the case with most of the work, as well as the grinding and whetting of knives. With the wrong method, a good knife can be finally ruined. With a little patience and effort you can turn the other way around even from inferior knives good cutting tools. How to proceed to grind a knife perfectly, we show you in the manual. In addition, we present you all possibilities with their advantages and disadvantages. In the future, you no longer have to destroy tomatoes and rolls when cutting and the steak is cut into bite-sized bites.
Material and preparation
You need this:
- Sharpening station
Costs and prices at a glance
There are many great grindstones that are gentle on the knife and not overly expensive. But you should pay attention to the size of the stone. With a tiny grindstone, the work gets fiddly, which is not a good idea, especially with a big knife. So look at the size of the stone very closely, because you want to grind larger knives with it.
- Waterstone japanese - 10 x 3 x 1, 5 cm - from 28, 00 Euro
- Waterstone - 15 x 5 x 2 cm - from 16, 00 Euro
- Combined stone from Belgian chunks and Pyrenees stone - 7 x 3 x 2 cm - from 20, 00 Euro
- Belgian chunks - extra fine - size 5 - about 10, 00 Euro
- Blue Belgian chunks - 10 x 5 x 2 cm - from 15, 00 Euro
Tip: If you want to buy a grindstone on the Internet, you should additionally check the ratings of other customers. There you will often find that there are actually some providers whose size specifications are given in square centimeters. There is then called a size of 19 to 22 cm², but in truth only a stone of 4 x 5 centimeters corresponds. This makes it hardly possible to sand a good knife.
Waterstone - fine cut
As a waterstone various very fine natural stones are called. They are very good for sanding. Although dark boulders often look just like a Belgian chunk, they can not be called that way unless they come from the special region in the Ardennes. Unfortunately, artificially made grindstones are often sold as waterstones, although they are actually much too coarse and can therefore cause scratches on the knife edge.
Belgian chunks - high-quality grindstone
There are a large number of different grindstones commercially available. Many offer two different grain sizes on both sides. However, a stone always stands out when it comes to high quality. This stone is even a part of gemstones. So he is repeatedly advertised as the finest grindstone in the world, we are talking about the Belgian Brocken. Even the ancient Romans are said to have sharpened their blades and knives with this whetstone from the Ardennes.
In a small area of the Ardennes is a deposit of Belgian chunks, which is about 480 million years old. Here at least since 1625, this type of slate has been proven to be mined for sale as a grindstone. But not only slate is contained in this grindstone, it is also still included volcanic ash. In addition, grenades are embedded in fine quantities in the Belgian chunks. As a result, this grindstone is used only minimally. If other pressed stones have already been completely sanded, you will have at most one barely visible hollow in a Belgian chunk.
- volcanic ash
The Belgian chunks do not need to be soaked or tanned long. He does not absorb water that much anyway. You just have to wet the stone with water to grind the knife.
Sharpening steel - temporary solution for in between
The sharpening steel may offer a quick fix and a slightly sharper knife. But the knives are not really sharper, only the softer part of the steel in the cutting edge is roughened. As a result, the knife cuts better again for a short time. In the long run, however, the cutting edge will be damaged and you will have more work to sharpen the edge again later. Above all, good and expensive knives should not be treated with a sharpening steel. Take the time and grind a high-quality knife regularly on a carefully selected grindstone by hand.
Tip: Sharpening stations, through which a knife edge is pulled wedge-shaped, should also be used only for cheap knives that you eventually dispose of anyway without much loss. The knives can warp during this treatment and the steel can get fine cracks. You will not notice these cracks until the knife breaks through.
Quick Start Guide - Use sharpening steel
We've all seen on TV, as the relevant chefs nimbly pull the knife over the sharpening steel. Unfortunately mostly wrong! If you are still inexperienced, you should support the sharpening steel, which also helps to keep the angle.
- the sharpening steel is supported with the tip on the worktop
- the knife is held against the steel at an angle of 15 to 20 degrees
- start with the end of the blade at the top of the sharpening steel
- Then pull the knife off with gentle pressure over the full length of the sharpening steel
- repeat this movement up to ten times
- then pull the knife over the other side of the sharpening steel
- The same number of sanding trains should be used
Sharp and hard - high quality knives
How sharp a knife becomes even with the best grinding method, but not only depends on the grinding. The quality of the steel also plays a major role. The high carbon in the steel ensures that it gets fine. But if the steel contains a lot of chrome, so that the knife does not rust so fast, the steel itself remains a bit coarser and the knife never gets as sharp as a comparable knife without the high chromium . However, these differences are hardly visible to our eyes.
The hardness of high-quality knives is given in HR hardness according to Rockwell. The particularly high-quality and sharp Japanese knives in the special trade have up to 64 Rockwell. Due to this high hardness, however, knives become relatively brittle, which makes them susceptible to breakage. Since the normal users handle but rather relentlessly with their knives and like to chop some vegetables with it, in Europe usually only high-quality knives are offered, which have between 56 and 58 HRC. For cheap knives, the manufacturers waive wisely on the indication of the HRC value. That should be far below 50 HRC.
Tip: If you want to buy a really high-quality knife for a higher price, you should pay attention to the HRC value and handle the cutting tool with care.
Grind knives - the manual
If you miss the hints for motorized grindstones you will not be happier. They do not cost too much and can be connected to any power outlet, the motorized grinders with the two round grindstones. But they damage a high-quality knife sustainable because the steel is too hot and anneals in the sequence. In addition, if you are not sharpening a knife on the electric grinder every day, the result of sanding over the blade is always a bit uneven.
Tip: When grinding, remember that you can only grind knives with a smooth blade. A toothed bread knife can not be sharpened on a grindstone so easily. For this you need special tools and skills.
- Water or moisten stone
Depending on which stone you use for grinding, it usually has to be completely immersed in water for some time. The grindstone then sucks with water and the air escapes from the inclusions in the stone. For about ten minutes, the stone should stay in the water. If there are still numerous air bubbles, you should wait a moment.
Tip: If the stone remains dry in the middle, it can easily break under heavy pressure. In addition, you should add more cold water more often with longer loops. This will prevent your knife from annealing or damaging the stone.
Water stones and Belgian chunks need only be wetted on the surface with water. However, you should pay more attention to the addition of cold water here during a longer grinding cycle, so that the knife does not get too hot.
- Find and hold the angles
The knife will create a kind of mud when sanding on the wet stone - this is normal and wanted. Many users who use a knife for the first time rinse off these abrasive particles, but this only lengthens the sanding process and wears out the stone. The angle at which you lay the knife on the grindstone during grinding is between 10 and 15 degrees. If you use grindstones with different grain sizes, always start with the coarsest grit and then work your way through the finer grits to polishing.
Tip: You can make the right angle by placing the knife on the grindstone yourself with a little help. Just put two 5-cent pieces or similar pieces of money on the grindstone. If the knife then rests on the coins with the back of the knife, you have approximately the right angle for a perfect finish. There are special clamps that you can push on the back of the knife to reach the right angle. A clothespin does it just as well and much cheaper.
Depending on the source, it is recommended either to pull the knife parallel over the grindstone or to pull it lengthwise along it. Which variant suits you better depends often on the size of the grindstone. The blade should be pressed down slightly with your thumb. If you have a longer knife, cut it piece by piece first on one side and then on the other side. Always start at the top of the knife. Keep the angle at which you move the blade as evenly as possible.
Tip: Look well after some time on the cutting edge. If necessary, take a magnifying glass with you for grinding. There at the cutting edge will form a fine ridge, which is difficult to see. You can feel it with your finger, but you should be careful not to cut yourself. Whenever the grade has come, you can move on to the next section.
Do not forget to moisten the stone again and again and not to remove the grinding mud. If you use differently grained stones, you should first completely machine the knife from both sides with the coarse grain. With the finer grain, the knife is then removed completely in the next step.
In the last step, the blade is reground with a fine grain. The burr is then completely sanded off. However, if you use one of the fine water stones or a Belgian chunks, the blade is now only once again finely reground to sharpen the blade evenly. Only when you are completely finished with the grinding, the grinding sludge is rinsed off.
Tip: Knife and stone should now be thoroughly cleaned of the grinding sludge. However, you should never apply soap or other cleaning products to the stone. Also, grinding oil, which may be useful in other work, you should not let come on the stones.
Great guide as a video
Tips for quick readers
- Check the quality of the knife
- short-term help with the sharpening steel
- do not use grinding stations or rapid grinders
- do not use electric grinders
- Select the grinding stone
- Water the stone or moisten it with water
- Place knife at the correct angle
- Pull blade parallel or lengthwise over whetstone
- Press the thumb lightly on the blade side
- Rinse knife and stone temporarily
- Gradually grind knives in sections
- Do not remove grinding sludge
- then grind second side
- Finely grind the knife and deburr
- only now rinse off the grinding sludge