potato cut. Is convex the real ultimate?

I made some foodie-magazine-photo-shootout mashed potato today.

There would be nothing worth mentioning, but after peeling my almond potatoes, i would slice them with a knife. :spiteful:

Now, I used very popular brand of cheapo knife. When slicing with the heel area, the potato would stick as hell, i would use certain amount of force to unstick it out, BUT when I used thin piece around the tip there would be no sticking at all. There was still enough steel to cover whole cut, but the blade was significantly thinner.

How is that possible?
Is thickness matters more than the actual grind? Cause thats what it looked like?

My thick Mizunos are great potato cutters.

It's possible the distal part of the knife had more contour.

bieniek said:

How is that possible?
Is thickness matters more than the actual grind? Cause thats what it looked like?

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Yes, because the geometry/convexity promotes food separation by pushing the pieces away.

My Sakai Yusuke western was perfect for potatoes because of its subtle convex grind and distal taper - with a push, the slices would just gently fall away to the side with a 'plop'.

The Victorinox Forschner 10cm utility is also excellent because it's a thin and narrow stamped knife with no geometry or convexity whatsoever - it just flies through the potatoes with no resistance or sticking whatsoever.

Im still not satisfied. The old thick german killer is great on potato also, because its breaking potato in two rather than cutting

This is a good question here... Can't think of a reason why it wouldn't stick on the tip if that part of the knife covers all the potato being cut too... I would be inclined to think its a matter of technique being used or some factor you didn't notice.

Anyone have a clue on this one?

It was just about the same up down move, might be slightly different but nothing much!

Salty dog said:

My thick Mizunos are great potato cutters.

It's possible the distal part of the knife had more contour.

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Indeed. It's pretty uniform up to the belly, but after that, things get funky, geometrically speaking. Could make it harder to find a plane to stick to.

+1 Eamon
I've more sticking with some very thin Japanese than with a fat almost German stainless Sabatier...
Convexity is sure a factor, but the cutting angle as well. With the asymmetric Japanese blades most will not hold their knives purely perpendiculary, but somewhat twisted clockwise - just a few degrees.
The blade's finish seems to have some role as well.

The Ealy is a great potato chopper.

Like I give a crap?

I've noticed on some hand ground knives the distal part of the blade sometimes is more convex because of the shorter height and grinding on a slack belt.

And a certain amount of wedging isn't a bad thing.

i gave my kagayaki vg10 wa-hale the convex love(2hrs with a #1000 stone) then a round of my 4k stone, and a 8k superstone to snug that suker up...dind't fell "safe" gave it a run on the basla + softwoood- ****t this give me a 240mmm gyuto with close to 100% less "stickgin". and a hairsplitting
)

and to separate confusion and twistington
drukness <--- not for "real". :O

The surface area vs the weight of the slice is also important. With knives with pointy tip areas (short edge to spine distance) there is less surface area and thus less sticking (unless you're cutting VERY small potatoes. You get the same effect with sujis. If you use a suji as an all arounder, you will get less sticking on the large objects independent of convexity. Pettys, of course are the same way. In one example, I had the same model, same maker with the same steel. One was flatter at the tip than the other and a little less pointy. The one with the flatter, larger tip was MUCH worse. It was no comparison.

tk59 said:

You get the same effect with sujis. If you use a suji as an all arounder, you will get less sticking on the large objects independent of convexity.

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Yessir! I fly through potatoes with no sticking because of the narrow blades.

Benuser said:

+1 Eamon
....The blade's finish seems to have some role as well.

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I believe that's an even bigger factor than geometry, at least in my experience.

ecchef said:

I believe that's an even bigger factor than geometry, at least in my experience.

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But then there is Salty and his army of mirror polished honeys that separate just fine.