Sharpening stones, also known as whetstones, are a type of stone used to sharpen knives. Sharpening stones include water stones (whetstones used with water) and oil stones (whetstones used with oil). Water and oil provide a lubricant on the surface to eliminate any extraneous friction, improve sharpening power, and prevent damage to the stone itself.
Many chefs prefer a water stone to an oil stone – water is more convenient and facilitates a faster knife sharpening. For this guide, we will be referring to water stones when using the term "whetstone."
How Do I Use a Whetstone?
Whetstones come in different types of materials and coarseness. Coarse grit stones can be used on duller knives that need significantly more upkeep. Fine grit stones fine-tune the knives for greater precision and polishing. We recommend purchasing both a coarse and fine grit whetstone.
First, you will soak your whetstone in water. Fine grit whetstones only need a few minutes of soaking; some chefs do not soak their fine grit stones to prevent any risk of cracking. Coarse grit whetstones should soak for 15 to 20 minutes.
Once soaked, place a coarse grit whetstone on top of a kitchen towel. Drag your knife towards you with a firm, even pressure at a 15 to 20-degree angle. Keep in mind that these angles may vary slightly depending on the type of blade you have. Continue repeating these strokes about ten times, then turn the blade over and sharpen the other side. Note that Japanese single beveled knives require sharpening on one side only.
Repeat the same process with the finer grit whetstone. The most challenging aspect of sharpening with a whetstone is maintaining the correct angle. When starting, it can be helpful to use angle guides to ensure you're sharpening correctly. (You’ll see I’m using one in the photos!)
The Pros and Cons of Whetstones
Compared to other forms of knife sharpening, whetstones have a few benefits.
- Whetstones offer significantly more control over the exact angle and sharpness of your knives.
- Their sharpening mechanism is more delicate, shaving off less metal than, say, an electric knife sharpener.
- Whetstones are less likely to damage your knives.
- Whetstones require a steeper learning curve to get used to. A little practice goes a long way.
- Whetstones require some setup and maintenance. Many stones need a soak before use.
What Kind of Whetstone Should I Purchase?
We cover the best sharpening stores in this article here: The Best Sharpening Stones in 2021. Consider purchasing both a coarse and fine grit stone (either a two-sided stone or two separate stones).
How to Use a Whetstone (Step-by-Step Instructions)
Because all whetstones are a little different, you should use these instructions as a guideline. Be sure to read your own instruction manual to supplement this information.
1. Assess the current state of your knives. Duller knives will need coarse and fine grit sharpening, while sharpener knives will only need fine grit sharpening.
2. Soak the whetstone: Soak your coarse grit whetstone for 15 to 20 minutes. Soak your fine grit whetstone for 5 minutes.
3. Remove the whetstone and set on a towel: After soaking, place your whetstone in the center of a kitchen towel. If desired, place an angle guides in the bottom center of the whetstone to ensure you're sharpening correctly.
4. Begin sharpening by dragging the tip towards you: Place your knife diagonally on the whetstone, such that the tip of your knife is at the top-left corner of the whetstone. The heel of the knife should be at the bottom-left corner, jutting off the whetstone, as demonstrated in the photo.
Place two fingers at the tip and hold your knife at a 20-degree angle. With firm, even pressure, drag the tip towards you.
5. Release the pressure and repeat: Release the pressure as you move your knife back up towards the top-left corner and repeat the previous step to drag the blade with firm, even pressure.
As you continue repeating the strokes, move your two fingers down the length of the blade. For example, the first stroke focused on sharpening the knife's tip, so by placing pressure on the middle of the knife, you can begin sharpening the middle.
6. Repeat the sharpening strokes: Repeat the sharpening strokes at least ten times on one side or as much as 40 to 50 strokes for duller knives. When sharpened sufficiently on a coarse grit stone, you should be able to feel a burr on the edge of the knife.
7. Flip the knife and repeat: Flip the knife and repeat on the other side to remove the burr and finish the sharpening process. This time, you will arrange the tip of the knife on the bottom right corner of the stone and drag the knife away from you. Gently release the knife towards you and repeat. Always ensure you are maintaining the same angle as you drag the knife away from you.
8. Repeat the sharpening strokes Repeat this method with your finer grit stone.
9. Wash and dry your knife: Wash and dry your knife thoroughly to remove any silty water. Test that the knife is sharp enough by slicing a tomato or cutting through a piece of paper.
If you have any questions on this method, I highly recommend watching this video on how to sharpen a knife using a whetstone by a Japanese master knife sharpener.
How to Store and Care for Whetstones
To clean a water stone, run it under water to remove any sediment. Dry with a paper towel, then let fully air dry before storing. Keep away from extreme temperatures, preferably in a dry location away from light.
Alternatives to Using Whetstones
Whetstones can be an excellent option for home cooks, but there are a few other alternatives:
- Electric knife sharpeners are easy to use, generate a sharp blade, and do the job quickly. To learn more about this tool, head to this guide on How to Sharpen a Knife with an Electric Knife Sharpener.
- Professional service: Local kitchen stores and bladesmiths often offer knife sharpening services, typically ranging from a $5 a knife to $20 a knife.