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Updated August 2026 · 6 min read · UK Japanese knife specialists
A whetstone is the best way to bring a dull knife back to life, but before you start sharpening there's one question that trips almost everyone up: how long do you soak the stone? Get it wrong and the stone either dries out mid-sharpen or, at the other extreme, sits in water so long you start to worry you've ruined it.
The good news is the answer is simple, and a stone is much harder to over-soak than you'd think. Here's exactly how long to soak a water whetstone, when you can skip soaking altogether, and how to store the stone so it's ready next time.
In short
Soak a water whetstone for 15–20 minutes before sharpening — until it stops releasing air bubbles. It can't really over-soak (it only holds so much water), but many splash-and-go and combination stones need no soaking at all, so check the maker's guidance. Never soak an oil stone. Keep a spray bottle handy to top the surface up as you work.
Do you even need to soak a whetstone?
The word "whet" is old English for sharpening — it has nothing to do with water — so not every whetstone actually needs soaking. There are three broad types, and they behave very differently:
Water stones are the classic Japanese sharpening stone. They're porous and are lubricated with water, which floats away the metal slurry as you sharpen and keeps the surface cutting cleanly. Most benefit from a soak first. Splash-and-go stones (including many modern combination stones) only need a splash of water on the surface — soaking them can actually cause problems, so always check. Oil stones are lubricated with honing oil and must never be soaked in water — water will stop them cutting properly.
Soaking a true water stone matters because a dry stone wears faster, cuts less efficiently, and lets the slurry clog the surface. A well-soaked stone glides, lasts longer, and does a better job — which is why we always recommend a proper water whetstone for maintaining hard Japanese-steel knives.
How long to soak — by stone type
| Stone type | Soak time | Notes |
|---|---|---|
| Splash-and-go / combination | None | Just wet the surface as you work |
| Standard water stone | 10–15 min | Soak until bubbles stop rising |
| Coarse / thirsty stone | 15–20 min | Low grits drink more water |
| Oil stone | Never | Use honing oil, not water |
The simplest test: drop the stone in water and watch for air bubbles. While bubbles rise, the stone is still drinking. When they stop — usually around 15 minutes for a standard stone — it's fully saturated and ready. You'll likely top the surface up once or twice mid-sharpen; a spray bottle makes that quick and mess-free.
Can you over-soak a whetstone?
For the most part, no. Think of the stone like a sponge — once it's full, it simply can't take on any more water, so leaving it in a little longer than planned does no harm. Where it can matter is leaving a stone submerged permanently, or in freezing conditions, which is a different question.
Can you leave a whetstone in water between uses?
It's tempting — leave it soaking and it's always ready. Some stones are fine with this; others aren't, so check the manufacturer's guidance. The risks with a permanently-soaked stone are:
✓ Degradation — some synthetic stones slowly break down when kept submerged.
✓ Cracking — if the water freezes, it expands inside the stone and can crack it.
✓ Mould and smell — still water grows mould, which is unhygienic near food.
If you do store a stone in water because you sharpen daily, change the water regularly and add a single drop of washing-up liquid to keep it clean. Otherwise, it's safer to soak before each session.
Drying and storing your stone
If you'd rather store your stone dry, let it dry slowly and evenly — drying too fast can cause a stone to crack, and putting it away while the inside is still damp can lead to mould. Allow at least 24 hours before boxing it up. Some premium stones aren't designed to dry out completely, so again, follow the maker's instructions.
Stone not staying wet? Take it off any towel (the towel wicks the water away), and if it's brand new, lightly flatten the surface with a flattening stone to remove the factory glaze that can stop it absorbing.
Need a stone that just works?
Our Whetstone Sharpening Stones (400/1000 · 3000/8000) are a complete two-stone system for taking a hard Japanese edge from repair to razor-sharp — £59.99, rated 4.86 from 117 reviews.
View the whetstone →Not sure which grit you need? Our guide to what grade of whetstone to buy breaks it down, and how to sharpen a knife on a whetstone walks through the technique once your stone is soaked.
Frequently asked questions
How long do you soak a whetstone?
Soak a standard water whetstone for 15–20 minutes, or until the air bubbles stop rising. Coarser low-grit stones can take the full 20 minutes; finer stones need less.
Do all whetstones need soaking?
No. Splash-and-go and many combination stones only need water on the surface. Traditional water stones benefit from a soak. Oil stones must never be soaked in water.
Can you over-soak a whetstone?
Not really — a stone only holds so much water, like a full sponge, so leaving it a little longer does no harm. The exception is storing it permanently submerged, which some stones don't tolerate.
Can you leave a whetstone in water permanently?
Only some stones. Permanent soaking risks degradation, cracking if the water freezes, and mould. If you do it, change the water often and add a drop of washing-up liquid. Check the maker's guidance first.
Should you soak an oil stone?
No. Oil stones are lubricated with honing oil, not water. Soaking one in water will stop it cutting properly.
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