How do I stop my Japanese knife from rusting?

Hand-wash and dry the blade immediately after use, never leave it wet or soaking, and wipe carbon-steel blades with a thin film of food-safe mineral oil between uses. A grey patina on carbon steel is normal and protective; active orange rust is the thing you are preventing.

How do I remove rust or stains from a carbon-steel knife?

Light surface rust and stains lift with a polishing paste — we stock Koyo Sunlite Polishing Paste (Blue for Steel) for exactly this. Work it gently along the blade, then wash, dry and re-oil. A stable grey patina, by contrast, is best left alone rather than polished away.

Rust, Patina & Knife Care

Q: 我要怎麼防止生鏽並保養碳鋼刀？

清洗後立刻把刀擦乾，處理酸性食材時中途也要擦拭，收納前薄薄上油。灰色養色屬正常現象；橘色活性鏽點才是問題。

How to prevent rust, why a patina is normal on carbon steel, and the mineral oil and polishing paste we stock for routine care.

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From the Knives and Stones workshop

Our own sharpening and care tutorials — tap to play.

DIY Board Wax (Butter) with Beeswax, Mineral Oil and Coconut Oil

HOW TO USE: Koyo Sunlite Polishing Paste (Blue for Steel)

Questions about this

我要怎麼防止生鏽並保養碳鋼刀？

碳鋼會與水分、酸與食物反應，所以最重要的習慣就是：每次洗完立刻把刀徹底擦乾，切檸檬、番茄、洋蔥等酸性食材時，中途也要隨手擦拭。絕對不要把刀泡在水裡或丟在濕的水槽裡。

隨著使用累積的灰藍色養色是正常甚至具有保護性的；真正要預防的是活性橘色鏽斑。如果刀會一段時間不用，收納前在刀身上擦一層極薄的食品級油。

我們的 K&S 建議，只談目前有現貨的：日常防鏽使用醫療級 Kitchen Knife / Cutting Board Mineral Oil，若要去除輕微浮鏽或刷新表面，則用 Koyo Sunlite Polishing Paste（Blue for Steel）。我們沒有販售山茶油或 Tsubaki 油，因此會改推薦礦物油作為替代。

✓ Verified by Knives and Stones · 張志豪 · Reviewed 3 Jun 2026

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