The SLIPA Sharpening Guide

Your free guide to sharp knives with SLIPA PRO. Everything below takes about ten minutes to read and will save you hours at the chopping board.

1. Is my knife dull? The tomato test

Rest the blade on a ripe tomato without pressing. If it sinks into the skin under its own weight, the edge is fine. If it slides off or squashes the tomato, it's time to sharpen. A sheet of printer paper works too: a sharp knife slices it cleanly from top to bottom without snagging.

2. Pick the right angle

  • 15° for Japanese knives (santoku, gyuto, nakiri) and thin, hard steels such as Damascus or high-carbon blades. A finer, more precise edge.
  • 20° for European knives (most chef's knives, utility and paring knives). A tougher edge that lasts through daily use.
  • Not sure? Use 20°. It is the safe choice for most knives.

Always sharpen the same knife at the same angle, so you build on the existing edge instead of grinding a new one.

3. Sharpen in five steps

  1. Wipe the blade clean and dry. Place the angle block on a flat, stable surface.
  2. Rest the flat of the blade against the magnetic face of the block, spine up, edge just above the worktop.
  3. Fit the coarse 400 disc facing the blade and roll the SLIPA roller back and forth along the whole edge, 15 to 20 strokes, with no extra pressure: the roller's own weight is enough.
  4. Turn the knife over and repeat on the other side.
  5. Swap to the fine 1000 disc and repeat on both sides, 10 to 15 strokes each, to refine and polish the edge.

Very dull knife? Spend longer on the coarse disc first. You should feel a tiny burr along the opposite side of the edge before you switch to the fine disc.

4. How often

If you cook every day, sharpen every 2 to 3 weeks. If you cook a few times a week, once a month is plenty. A few strokes on the fine disc between sharpenings keeps the edge crisp.

5. Keep the edge longer

  • Cut on wood or plastic boards, never on glass, stone or plates.
  • Hand-wash and dry your knives; the dishwasher dulls edges fast.
  • Store knives in a block, on a magnetic strip or in a sheath, not loose in a drawer.
  • Wipe the diamond discs with a dry cloth after use.

6. What SLIPA PRO is not for

Serrated knives (bread knives), ceramic knives and single-bevel blades need a different tool. Everything else in a normal kitchen drawer is fair game.

Questions? Email loominouscontact@gmail.com and we'll help.

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