Vivront founder Joseph Rueter joined KARE 11 to talk about kitchen knife safety, sharpness, and how a good edge can completely change the way you cook. As cooler weather brings on soup and stew season, Joseph shared why dull knives can make cooking harder and more dangerous—and how keeping them sharp helps you cook more often and with confidence.
Watch the segment
Interview Transcript:
HOST: The cooler temperatures are finally here, and that means soup season and stew season. But before you start chopping up all those veggies, you’ll want to make sure your knives are up to shape. This is something most kitchens don’t pay enough attention to, and it makes a world of difference when you actually get them sharpened.
Joseph Rueter is with Vivront in Edina. He’s got some tips on how to make the process safe and easy. I’ve had such a good time talking with you before the show about the science of knives. I didn’t realize certain knives have different concavities and why. We’ll get into that in a second, but first, what do you want people at home to know about knife quality and sharpness, and how it affects their cooking?
JOSEPH: Thanks for asking. When you’re working with harder vegetables, dull knives really persuade you not to cook at all.
HOST: It’s dangerous, too.
JOSEPH: It is. Dull knives bounce. Instead of slicing, they smush and tear. Sharp knives slice cleanly, and it makes such a difference.
HOST: So much more fun, too.
JOSEPH: Dull knives are just hard to use. They bounce right off your food.
HOST: Especially stuff like squash and pumpkins. That’s when it becomes dangerous because those skins are so rigid and tough.
JOSEPH: That’s right.
HOST: Unless you have a super sharp knife, it completely changes the job.
JOSEPH: Exactly. Sharp, and thinner helps too. This one here is by a local maker, Hall Made, from his Origin series.
HOST: And that’s a Japanese style?
JOSEPH: More broadly Asian in style. They’re flatter toward the heel, thinner overall. Not great for side-to-side chopping, but excellent for slicing. If you’re cutting acorn squash, maybe adding a little brown sugar and happiness.
HOST: (laughs) And some butter. I like happiness.
JOSEPH: Stay away from the stems when you cut and you’ll have a much easier time.
HOST: And they’ll cook more evenly, too.
JOSEPH: Exactly. Even cuts cook evenly.
HOST: Okay, you’re in the knife sharpening business, and of course you want to make money, which is understandable. But what’s the real difference between sharpening at home and getting it done professionally?
JOSEPH: Great question. As a knife dulls, the metal actually pushes to one side. Right-handers push it one way, left-handers the other. You can use that honing rod in your knife block, the one most people never touch, to push that bent metal back straight as long as the metal is still there.
Once it’s rounded and that edge is gone, you need to recraft it, and that’s sharpening. Some pull-through gadgets grind away too much metal, changing the shape of the blade. That affects how it feels and how well it cuts, especially with herbs or fine ingredients.
HOST: So how do you do it?
JOSEPH: We use a series of abrasives depending on the knife. Japanese knives, for example, often have a single bevel, so we treat them differently. We’re pretty good at knowing what each knife needs for its best edge.
HOST: So it’s not just the tip that matters. You’re shaping the metal itself, then finishing it super thin at the end?
JOSEPH: Exactly. If we’re going full knife nerd here, we’re talking about a primary bevel, a secondary bevel, sometimes even a tertiary bevel. Knife makers have their own steps in that process. The bevel is that angle at the end where the two sides meet. That point is the apex, and that’s what determines sharpness. What happens behind the edge is what lets the knife slide cleanly through food, and we manage that carefully.
HOST: Can you fix something like this? I have a Japanese-style knife at home. It’s super sharp but has a few chips in it.
JOSEPH: Absolutely. We’ll look at the profile, the shape, and restore it as close as possible to the maker’s original design. We can fix chips, rounded tips, broken points, all of it. Then we sharpen it properly.
HOST: You should take a food truck and go around neighborhoods sharpening knives.
JOSEPH: (laughs) We actually have one.
HOST: No way. Alright, Bobby requested that you toss a tomato. Can we try it?
JOSEPH: Let’s do it.
HOST: I’m not cutting, just holding. Ready? Go. (laughs) That’s pretty good.
JOSEPH: I should’ve thrown it higher. Gravity would’ve helped us out.
BOBBY (off-screen): How long will a sharpened knife like that stay sharp?
JOSEPH: Great question. It’s kind of like shoes. Knives are made for different uses. Pros who cook all day might need sharpening every two weeks. For most home cooks, once or twice a year is plenty. It really depends on how often you use them.
HOST: Awesome. Thank you so much, Joseph.
JOSEPH: Pleasure.
HOST: You can check out Vivront on France Avenue South in Edina. We’ve got more details at KARE11.com. I told you we’d nerd out, Joseph. Thanks again, and we’d love to have you back.
JOSEPH: Thanks so much. Pleasure being here.