Honing Rods

Since I’d never used a honing rod, I read the instructions (though some arrived without any) and practiced. The test kitchen’s preferred technique is to plant the tip of the rod on a cutting board, hold it straight, and slide the knife from heel to tip down each side of the rod at about a 15-degree angle, maintaining light, consistent pressure. While you could hone in the air, like my holiday host, we find this less reliable because you have two moving pieces, which makes it harder to keep a consistent angle. Happily, I discovered that honing is not that scary or difficult. You get a feel for it after several minutes’ practice. 

I dulled the cutting edges of nine new chef’s knives on that hard glass cutting board by chopping until the blade failed to cut smoothly through paper. This accelerated the typical effects of much longer use on more forgiving wood or plastic boards. I assigned one knife to each rod and started to hone.

Before honing and again after every few swipes, I tried to slice paper to help me gauge whether the blades’ sharpness had improved. Then, since nobody slices up paper for dinner, I used the newly honed knives to slice tomatoes, knowing that sharp knives would glide through tough tomato skin, while dull ones would squash it, making oozing slices. Next, I asked five testers with varying levels of honing experience to repeat my tests. Finally, I took the honing rods and the corresponding blades to a lab at MIT to examine them under a high-powered microscope. The results were revealing.

All the rods very quickly improved the knives’ cutting edges, usually within a half-dozen swipes on each side of a blade, but not all the rods produced equally improved edges. Our testers gave higher performance scores to the rods whose knives sliced paper and tomatoes most smoothly and effortlessly. Also, not all rods were equally easy to use.

The rods’ textures affected both comfort and performance. The roughest diamond-coated rod made a hideous scraping sound that testers hated as it scratched the knives’ blades. Another, more finely textured diamond-coated rod also roughed up our knives, but to a lesser extent. Both appeared to remove more metal from the blades than smoother rods, and we could see gray streaks when we wiped the blades on white dish towels. “I’d worry that if I got the angle wrong with these, I’d really damage my knife,” one tester said. Under the microscope, these impressions were proven: The rod that felt roughest was covered with bigger, more irregular diamond grains, while the rod that felt finer-textured actually was. While we like diamond-coated steel as the sharpening medium in our favorite electric and manual sharpeners, those tools have multiple sharpening slots that offer a progression of coarser-to-finer grit, ending with the gentlest finishing slot, but these diamond honing rods offered only one grit—a rough one. 

More moderately textured rods, such as those with ridges running vertically along their entire length, hit a middle ground, appealing to some testers who felt that the ridges provided a certain amount of “grippiness” that helped control angle and speed as we swiped blades along them. They were effective in restoring the knife edge with less scratching than diamond-coated rods. Under the microscope, we noticed that ridged rods differed in the number, proportion, and uniformity of their ridges. The ridges on one highly ranked model were more abundant, fine, and uniform than those on lower-ranked models with ridges. 

In the end, though, testers gave top marks to rods with smooth surfaces and rods with combinations of smooth plus lightly ridged textures, choosing them over the rods that were ridged all over. Like fine-grit whetstones, smooth-surfaced rods restored sharpness and left our blades with polished edges. On rods with dual textures, we usually started with a few swipes on the textured sides and then turned the rods 90 degrees to use the smooth sides for finishing the edges.

Contrary to conventional wisdom, even the smoothest rod still removes metal. We saw gray streaks—metal from the blades—all over our white ceramic rods. Experts warn that this hard-to-remove residue eventually builds up on ceramic rods, filling the surface pores and making them less effective at honing (see “A Neat Trick for Cleaning Ceramic Honing Rods”).

The length of a rod also mattered. The rods (minus handles) ranged from 8 to 12 inches long, and most testers agreed that longer lengths made it easier to keep the knife angle consistent and to run the entire blades down the rods. While we could shorten the stroke for a short rod, it took more effort; plus, we often found ourselves swiping the blade at a too‑wide angle on one side when we reached under the hand we used to hold the rod in place. Angle consistency is hard enough to achieve without obstacles.

One of the shortest rods also tapered sharply at the tip, a feature that testers disliked; rods of more consistent thickness helped us make predictably consistent knife swipes. We preferred thicker rods, too: These ranged from 3 to 5 centimeters in circumference at their centers; highly rated rods were among the thickest. Testers said that thicker rods made them feel more secure in controlling the movement of the knife. At the extreme, we especially liked one model’s unique flattened-oval shape; typically, honing rods are round.

And while they seem like minor factors, certain handle and tip designs made rods much easier or harder to use. Handles came in a variety of materials, but material didn’t significantly influence our preferences. What did matter was the shape of the handle where it attached to the rod: We preferred handles that didn’t flare out too broadly. Big, protective guards got in the way when honing with the tip of the rod planted on a cutting board. They forced us into a wider approach angle that wasn’t correct for our knife or made us start sliding the knife lower on the rod. A few handles came with “angle guides” built in to help us achieve a 15-degree angle, but in practice these were confusing to follow and often launched us in an odd direction, almost chopping into the rod. It’s important to try to swipe the blade at a consistent, narrow angle (as close as possible to 15 degrees to match the angle of our winning chef’s knife) along both sides of the rod, and this simply was easier to do when there was nothing in the way.

Tips were a minor but important part of the rod. Some rods came with rubbery or pointed tips meant to help them stay planted securely on the cutting board, but often these failed and let the rod slide around as we worked. We didn’t rely on them; instead, we used an old test kitchen trick, placing the tip on a folded, slightly dampened dish towel, which worked like a charm.

After hours of dulling and honing knives, we found our favorite: the Bob Kramer Double-Cut Sharpening Steel. We were surprised at how quickly it restored a sharper, polished edge. This rod made it easy to maintain a consistent knife angle because it was one of the longest and widest in our lineup. This is a steel rod with dual surfaces, two finely textured and two smooth, which helped gently align and touch up blades without apparent damage or removing excessive metal and gave us two stages for restoring the blade edge. (Generally you’d start with the textured sides and then move to the smooth sides, but both may not be necessary every time; it depends on how dull your knife feels). We tested this rod on our favorite carbon-steel chef’s knives and 12" slicing knife with equally good results. Since it’s a bit pricey at nearly $50, we also chose a Best Buy: the Idahone Fine Ceramic Sharpening Rod, 12", which costs about $35. Like our top-rated model, this rod is also 12 inches long and comfortable to use, and its smooth white ceramic surface was comparatively gentle while still effectively touching up the knife’s edge.