Soak, Splash or Diamond: How to Choose the Best Whetstone

A busy taquería line goes through knife edges fast. Onions for every order of tacos, a crate of tomatoes for pico de gallo, bunches of cilantro, limes by the case and grilled steak sliced thin for fajitas all wear an edge down in a single service. A whetstone is the oldest and still the most controllable way to bring that edge back, and it is gentler on a good knife than most machines.

The trouble is the choice. There are water stones that need soaking and others that only want a splash, diamond plates that never wear hollow, oil stones in a rotating tray, and grit numbers that run from a few hundred to many thousands. This guide explains what those differences mean, what each maker says about soaking and flattening, and which stones are worth buying for a home kitchen.

Julia’s earns a commission on purchases made through links on this page, at no cost to you. Recommendations are based on what a restaurant kitchen looks for in a whetstone, the makers’ own specifications and the details on each Amazon listing.

Quick verdict: which whetstone to buy

The rest of this page explains how these stones differ, which grit you actually need, and how to keep a stone flat so it keeps giving a straight edge.

Five whetstones side by side

Our five standout stones, one for each kind of cook, with the grit and preparation each maker or listing states. All eight stones are reviewed in full below.

Product images from Amazon. Soaking and preparation are as stated by each maker or, where noted, by retailers that sell the stone; check the instructions that come with yours.

Our picks for the best whetstone

These nine stones cover every kind of sharpening surface a home cook is likely to want: combination water stones that handle repair and routine work in one block, single stones that need no soaking, a medium stone with its own case, a finishing stone for a polished edge, two diamond plates and an oil stone system. Each pick explains who it suits, what the maker says about preparation, and one honest reason to skip it.

Grit numbers, explained

The number on a whetstone tells you how coarse its abrasive is. Lower numbers remove metal fast; higher numbers remove very little and polish what is there. Japanese stones are usually graded on the JIS scale, which is what Zwilling cites for its finishing stone. Diamond plates are often described in microns or mesh instead, and Western oil stones by names such as coarse, medium and fine. The scales are not identical, so treat cross-comparisons as rough.

For most home cooks, a stone around 1000 is the one that matters. Add a coarse stone if your knives get chipped, and a finishing stone if you enjoy the process and want a smoother edge. Our knife sharpener vs whetstone comparison explains when a stone is worth the learning curve at all.

Soak, splash or oil: what the makers say

The single most confusing thing about whetstones is the preparation, and the honest answer is that it depends on the stone, so read the maker’s instructions. Here is what the makers and sellers of the stones on this page say:

• Soaking stones. Shun’s listing says to soak its 300/1000 stone before use. Korin warns that soaking finishing stones of about 3000 grit and finer can crack them.
• Splash-and-go stones. Zwilling says its Twin Pro 250/1000 needs no pre-soaking, just a few drops of water.
• Diamond plates. DMT’s listing says its stones work dry or with water, with no oil needed.
• Oil stones. Norton’s IM313 keeps its stones in an oil bath. Keep an oil stone to oil; a water stone is used with water.

Whichever type you use, keep the surface wet (or oiled) while you sharpen, rinse the stone afterwards, and let water stones dry slowly in the air before you put them away.

Keeping a stone flat

Water stones wear fastest where the blade passes most, usually the middle, so over time the surface dishes. A dished stone sharpens a slight curve into the edge, and the knife stops meeting the cutting board along its whole length. That shows up as onion slices that stay joined at the bottom.

The fix takes two minutes. Draw a pencil grid across the wet stone, rub it on a flattening plate such as the DMT DuoSharp coarse plate or another coarse diamond plate until the pencil marks are gone, then rinse. Soft soaking stones need this most often; harder splash-and-go stones less so; diamond plates never. Many cooks flatten every few sessions, before the dish becomes visible.

How to choose a whetstone for home use

Start with a stone around 1000 grit. It does most of the work. A combination stone with a coarse side, like the Zwilling 250/1000, also covers repairs.

Decide how much waiting you will tolerate. Soaking stones need a few minutes in water first; splash-and-go stones and diamond plates are ready at once. If you sharpen on impulse, choose a stone that does not need soaking.

Match the stone to your knives. Very hard Japanese steels sharpen well on fine stones and diamond plates; softer German knives sharpen quickly on almost anything. See our guides to the best Japanese knife and the best chef’s knife for the steels each maker uses, and check the maker’s recommended angle, such as the 16 degrees Shun gives for its double-bevel knives.

Choose a full-length stone. About 8 inches long and 2.5 to 3 inches wide is standard; a short stone works but makes long blades slower to sharpen.

Plan for a base and flattening. A stone that slides is dangerous. Choose one with a base or holder, or set it on a damp towel, and budget for a flattening plate if you buy water stones.

How we chose these eight stones

We began with what a kitchen that cuts onions, chiles, tomatoes, citrus and grilled beef every day needs from a stone: a dependable edge, sensible grits, a stable base and upkeep a home cook will actually do. We then looked for stones sold on Amazon in the United States from identifiable makers, across every main type, and checked each one’s stock with Amazon’s product data before writing. Grits, sizes and preparation come from the maker’s own pages where we could reach them and otherwise from the Amazon listing or named retailers; where none of them states a figure, we say “not stated”. We left out stones that were down to their last few units when we checked, including several Naniwa, Suehiro, King and Shapton stones, and unbranded kits whose listings promise more than they document. We did not sharpen knives with these stones for this guide, and we have not cited published equipment reviews, because we did not read them for this page.

Whetstone questions, answered

What is the best type of whetstone for a beginner?

A combination water stone with a 1000 side, ideally one that does not need soaking, such as the Zwilling Twin Pro 250/1000. It covers routine sharpening and the occasional repair, and it is ready with a few drops of water.

Which whetstone brands are worth trusting?

Shapton, King, Naniwa and Suehiro are long-standing Japanese stone makers. Knife makers such as Zwilling, Wüsthof and Shun sell stones designed around their own knives. DMT and Atoma are known for diamond plates, and Norton for oil stones. Be cautious with unbranded kits that bundle many accessories but publish few specifications.

Do I need to soak my whetstone?

Only if its maker says so. Some water stones must soak until the bubbles stop; others are splash-and-go; diamond plates never need it; and oil stones use oil, not water. Soaking a stone that is not meant to be soaked, especially a fine finishing stone, can crack it.

What grit whetstone do I need for kitchen knives?

A stone around 1000 grit handles most sharpening. Add something around 200 to 400 for chips and very dull blades, and 3000 or finer for a smoother finish.

Is a diamond plate better than a water stone?

Neither is better for everyone. A diamond plate is always flat and always ready, and it cuts hard steel fast. A water stone gives more feedback and a smoother edge at higher grits, but it needs flattening.

Should I still use a honing rod if I own a whetstone?

Yes. A rod realigns the edge between sharpenings, so you visit the stone less often and remove less metal over the life of the knife.

Our final pick for a sharp edge

Buy the Zwilling Twin Pro 250/1000 if you want one stone that rescues dull knives and keeps sharp ones working, with no soaking. Choose the Norton Tri-Stone if you prefer oil, the KAI Seki Magoroku 1000 if you want a medium stone with a storage case, and the DMT diamond stone if you never want to flatten anything. Add the DMT DuoSharp coarse plate the day you own more than one water stone.

If you would rather have a machine do the work, our best knife sharpener guide covers electric, pull-through and guided sharpeners. For the knives themselves, see the best knife set, and keep the edge longer on a good cutting board. The rest of the kit is in Mexican cooking tools.

A good stone pairs with regular honing between sharpenings; see the best honing steel and, for harder Japanese blades, the best honing steel for Japanese knives.

Starting from scratch? Our guide to the best whetstone kits covers sets with several grits, a base and a flattening stone.

On a budget? See our guide to the best cheap whetstones.

Related guide: Best whetstone for beginners.

And if you would rather someone else did the slicing tonight, see the menu or call to order.