A whetstone is a tool used to sharpen your knives – and a really good investment if you want to keep your knives sharp for life.
But if you're new to the world of whetstones, you can quickly become overwhelmed. You'll be introduced to different types of stones, sharpening angles, grain sizes and different methods. So to keep you on your feet, I'll guide you through everything you need to know.
In this article, I'll cover the following:
- What is a whetstone?
- What do the different grain sizes mean – and when should you use them?
- How do you sharpen knives with a whetstone?
- Why is the angle important when sharpening your knives?
With that out of the way, let's dive a little deeper into what whetstones actually are.
What is a whetstone?
A whetstone is, as the name suggests, a stone used to sharpen knives. They come in different materials and grain sizes.
All whetstones from Gastrotools are industrially manufactured. This means that they have a better and more uniform grain size than if they were made from natural stone.
Similar to sandpaper, there are different grades of how fine they grind. The lower the number (e.g. #500), the coarser the whetstone. The coarse stones are used to straighten the knife edge, and the fine stones are then used to sharpen the knives to a razor edge.
The sharpening stones at Gastrotools have two sides with different grain sizes.
If you have not sharpened your knives for a long time, it is recommended that you start with a coarse stone so that the knife edge is completely straightened out, and then work your way up to a finer and finer stone.
Are you using the right angle?
When using a sharpening stone, you must hold your knives at the correct angle. The angle depends on your knives.
All our knives at Gastrotools should be sharpened at approximately 15-20 degrees, depending on preference. If you have classic Western knives in your kitchen, they should typically be sharpened at 20 degrees, while Japanese knife types are often sharpened at a smaller angle.
How to sharpen knives on a whetstone
We have now talked about materials, angles and grain sizes - and now we come to the most interesting part of it all. How to use a whetstone.
Step 1: Place your whetstone in water
Before using your whetstone, first place it in a bowl of water for 5-10 minutes. The reason for this is to avoid generating heat when sharpening the knives, and to give the stone time to absorb the water.
Heat will cause the steel to soften and thus remain sharp for a shorter period of time. The hardening will be destroyed if you are not careful – if you send your knives out for sharpening, you should also opt for wet sharpening.
Step 2: Align the knife edge on the coarse side
Now take your wet whetstone and place the fine side down in the rubber base provided so that it stands firmly on the table.
Hold your chef's knife at an angle of 15-20 degrees, press lightly on the blade and pull it down over the whetstone.
Repeat this 10 times and do the same on the other side of the knife. When sharpening the knife on one side, you can often feel a burr when it has been sharpened properly on the opposite side. This feels like a slight unevenness if you carefully feel the edge with your thumb.
To remove the burr, finish by gently sharpening the knife once on each side of the blade before moving on to finer grits.
Step 3: Turn the whetstone over and finish on the fine side
Hold your chef's knife at an angle of 15-20 degrees, press lightly on the blade and pull it down over the whetstone 10 times. Do this on both sides. *
*You may notice a grey liquid on your whetstone. This is residue from the metal – and you should not remove it. It just helps to sharpen your knife further.
You can repeat this exercise on finer and finer whetstones if you want your knives to be as sharp as razor blades.
When you have finished sharpening your knives, rinse your whetstone, let it dry and pack it away for next time.
So which whetstone should you choose?
There are, of course, several options. If I were to go to a desert island where I could only take one whetstone for my knives, I would choose our 500/1000# whetstone. The coarse 500 would be perfect for straightening the knife edge, and the 1000# would be suitable for getting a sharp knife.
That said, if I wasn't going to a desert island, I would buy a set of three whetstones so that I always have the sharpest knives in my drawer.
