How to Sharpen a Mandoline Blade on Whetstones
When you think of a mandoline slicer, you likely think of injured fingers. While I know many, many, many folks who have lost a fingertip to a mandoline, it was almost always because they were fighting with a dull one and slipped. Much like your kitchen knives, sharp mandolines are safer mandolines. Here’s how to sharpen your mandoline blade and keep your digits intact!
If you can, watch this video. I’ll do my best to explain the process, but it’s best explained through the visual medium. Otherwise, scroll down for the lowdown!
Equipment:
- Dull mandoline blade.
- Coarse grit whetstone, around 220 or 400 grit.
- Medium grit whetstone, around 1,000 grit.
- Fine grit whetstone, 3,000 - 4,000 grit.
- Leather strop.
You can get away with the first two stones, but you’ll get a much better edge with all three. Additionally, ensure you have some kind of stone holder to keep your stones stable and a truing stone to flatten your stones. Otherwise, you won’t get a straight edge on your mandoline.
How to Sharpen a Mandoline Blade on Whetstones
If you’ve ever sharpened a traditional Japanese single-bevel knife, sharpening a mandoline blade is very similar, but much easier! Essenitally, you’re sharpening one edge by raising a burr, then cleaning it off on the other side, and progressing onto the next stone until you finish on your fine stone. If you’ve never sharpened a knife before, I highly recommend starting here and getting familiar with basic knife sharpening before you sharpen your mandoline blade. In these instructions, I’ll be using a couple of bits of sharpener’s jargon, all of which are explained in that article.
First, make sure all of your stones are as flat as can be. Starting on your coarse stone, lay the blade flat on the stone, bevel side down, with the edge facing towards you. With the fingers of your non-dominant hand, press down just above the edge of the blade so it rocks up onto the bevel. Grip the back of the blade in your dominant hand, but don’t raise the blade at all. This is the angle you’ll be sharpening at (see below).
Keeping the edge on the stone, rotate the blade to run diagonally across it, allowing the entire edge to contact the stone at once (pictured at the top of the page). With light pressure along the edge, glide the blade gently along the length of the stone, wetting the stone as needed. Stop periodically and check for a burr along the edge of the non-bevelled side of the blade. Once you’ve raised a burr along the full length of the edge, switch over to your fine stone. Lay the blade flat on the non-bevelled side and gently run the blade along the stone until the burr is removed from that side. This prevents the blade from wearing too much, as it would if you removed the burr on the coarse stone.
Move up to your medium stone and repeat the process of sharpening the bevel. This time, the burr your raise will be smaller. Again, remove the burr on the fine stone and proceed to polishing the bevel on the fine stone. You won’t raise a noticeable burr, so I like to do a visual inspection. Check your bevel before polishing on the fine stone so you know what to look for. It’ll look noticeably scuffed on the medium stone, and very shiny once you’ve finished on the fine stone. Once you feel confident in the polish, subtly increase your sharpening angle fifteen degrees or so. Sharpen gently for a minute or two, you may notice a burr. Remove the burr as usual!
This final increased angle is called a ‘koba’, and it’s something you do to finish a regular Japanese knife. It reinforces the super-thin edge, allowing it to cut tough root vegetables without dulling or chipping easily. Finally, give your blade a strop at 15 degrees on the bevelled side and 0 degrees on the other side, to remove any residual burrs and make the edge silky smooth.
Excellent work, you’ve now sharpened your first mandoline blade! If you ever need help or ask questions, don’t hesitate to message us online or visit our shops in Toronto, Ottawa, Calgary, Edmonton, or Vancouver and we’d love to help.
