S-Grinds, what are they and are they worth it?

We look at what is an s-grind and does the it actually make a big enough difference in performance for the time and effort it takes to do?

The S-grind is a modern application of the age-old technique of fullering, as applied specifically to kitchen cutlery, in order to improve food release or put another way, reduce food striction (food items sticking to the blade).

Food striction is most notable when cutting vegetables like potatoes, onions, courgettes, and the like. The slices tend to stick and stack up on the side of the blade, which is annoying, takes time to clear, and reduces the precision of cuts.

Most production knives are fully flat ground, which food just loves to stick to. To solve this the production knife industry (Wusthof, Shun, etc) has been marketing “Graton” or scalloped bevels. These are the scalloped dimples you would have seen on the side of the blade, which aims to create an air pocket between the food item and the blade, thus breaking the surface tension and allowing the newly cut food item to fall away. While functional it does reduce the life span of the knife because as you sharpen the knife, you’ll eventually raise the edge up into the scalloped area of the blade.

Enter the S-Grind:

The s-grind was arguably popularised by Robin Dalman of Stockholm, Sweden in or around 2015 and has since taken over the world of high-end custom chef knives, especially knives by western makers. The Japanese makers Takeda and Kohetsu are well known for forging in wide s-grinds to their knives as well.

Choil picture of Robin Dalman's gyuto showing double s-grind.

Some makers were using this before Robin but he certainly thrust it into the limelight. Mareko Maumasi, Salem Straub, and Alec Steele (to name but a few) have also used the grind to good effect in their knives.

diagrame break down of an s-grind for kitchen knives

Essentially the s-grid facilitates a blade that is both lightweight and strong, as well as producing great food release. The blade is convex ground and then has two hollow grinds running the length of the blade (one on each side) to help release food from sticking to the blade. The hollows are typically inlaid with a 36″ / 1.5m equivalent radiused platen.

If you’ve seen swords being made on forged in fire, you’ll notice that some have fullers ground the length of the blade to reduce weight and maintain strength. The s-grind could in fact be considered, shallow fullers on a chef knife. Thus incorporating an age-old technique to modern kitchen knives.

Benefits:

The s-grind promises excellent food release, low striction when cutting food items. This does need to be fined tuned to perform at its best, as the hollow doesn’t guarantee all food will magically fall to the board. The cutting technique also plays a key role in popping the food off the blade as well.

Another benefit that is also found in convex grinds is the ease of cutting or in other words, minimalising wedging in harder food items like carrots, or butternut. Full flat grinds tend to wedge and then crack the food apart and you can definitely hear, feel and see this in action. By purposefully providing relief to the initial cutting edge, convex and s-grinds allow the blade to keep cutting all the way through the food. It almost drops through without any effort.

A good chef knife will be tapered both from the handle to the tip (distal taper) and from the spine to the edge. Knives that are considered “laser” class are gound incredibly thin for increased cutting performance. This can introduce a bit more flex than you may like. By having the hollow in the blade, the resultant peak creates a stiffening ridge that allows the thin blades to be both light and stiff.

The first s-grind I attempted was in 2019 for a custom-ordered santoku chef knife. A little bit of testing in the kitchen confirmed most of what I read and heard from other makers. My knives usually surprise people who pick them up at the show for how light they are and that’s just because of how thin I can grind them, along with the distal tapers. In combination with the s-grind, I can use thicker stock and still achieve excellent cutting performance and feel.

I have a custom-made 2-meter equivalent radiused platen which produces very subtle hollows on my already laser thin blades. It allows me not to grind through the middle of the blade and to “blend” the hollow during the final hand polishing phase.

In Conclusion:

Yes, the s-grind is worth having. It certainly takes more effort and time to make, but the results are worth it.

You’ll notice a big difference, especially if all your current knives are full flat grinds.

The main thing to look for in a high-end kitchen knife that has an s-grind is the thinness behind the edge. That thinness combined with the s-grind will translate into a fabulous cutting tool that you simply can’t buy outside of the custom knife world.