Testing Methodology
Testing Methodology
Every knife included in our ranking articles goes through the process described on this page. Publishing our test conditions in detail lets readers see exactly how our scores are produced.
01How we acquire knives
Knives reviewed in our ranking articles are purchased anonymously by our editors as ordinary consumers. Press samples sent directly by manufacturers are excluded from ranking coverage.
Why anonymous purchasing
Press samples can be hand-picked or specially prepared by manufacturers. Anonymous purchasing means we evaluate the same quality of knife an ordinary buyer would receive. When we do review a press sample (in non-ranking contexts), we always label it as such.
02Testing period
We use each knife for a minimum of four weeks before publishing. First-day sharpness alone says little about edge retention, sharpening behavior, or long-term handling.
- • Week 1: Out-of-box sharpness, initial feel, weight distribution, fit and finish.
- • Weeks 2–3: Daily use across home and semi-professional tasks; edge wear documented.
- • Week 4: Sharpening test on #1000 and #6000 whetstones; recovery and ease of resharpening assessed.
- • When possible, we record video of each test session.
03Cutting rubric (six tests)
We use a fixed set of foods and tasks so multiple knives can be compared on equal terms.
| Food | What we measure |
|---|---|
| Ripe tomato | Skin bite, thinnest clean slice possible |
| Onion (medium) | Food release on thin slices, clean cut through cell layers |
| Daikon (10 cm round) | Katsuramuki rotary peel possible, resistance on push cut |
| White fish (sea bream / sea bass) | Skin removal, hira-zukuri slice, pull cut smoothness |
| Herbs (parsley, shiso) | Damage at the cut surface, aroma retention |
| Chicken thigh | Tendon handling, work around bone |
In addition, a 30-minute continuous-use session tracks grip fatigue and how quickly the edge dulls.
04Scoring
For each test category, the six knives in a ranking session are ordered from 1st to 6th. 1st place earns 6 points, 2nd place 5 points, down to 1 point for 6th. No fractional or decimal scores are used.
Final ranking is the total across all categories. Ties are broken by the editor-in-chief's holistic judgment (balance, sharpening ease, price-to-performance).
05Hardware specs measured
HRC (Rockwell hardness)
Brand-disclosed values. We do not run our own destructive testing.
Edge angle
Visual inspection plus tape-angle measurement. Margin of error ±1°.
Weight
Digital scale, ±1g.
Blade length
Stainless ruler, ±1 mm.
Price
Based on purchase invoice. Quoted at the time of testing, tax-inclusive when sold in Japan.
Steel
Manufacturer disclosure. Labeled "undisclosed" when the brand does not publish the steel type.
06Standardized conditions
To isolate the difference between knives, we hold every other variable constant.
- • Cutting board: Hinoki cypress, 45×30×3 cm, the same board for every test.
- • Tester: The same editor (editor-in-chief) performs every cut.
- • Photography: Same 4K camera position, daylight plus 5500K LED.
- • Ambient: 22–25°C, 50–60% relative humidity.
- • Ingredients: Sourced from the same Tsukiji/Toyosu vendor on the same day, brought to room temperature before cutting.
07Excluded from scoring
Certain qualities are never part of our point totals. We may comment on them in the article body, but they do not affect ranking.
- • Aesthetic appearance and decorative finishing
- • Brand prestige or history
- • Packaging quality (wooden boxes, gift presentation)
- • Suitability as a gift item
These are valuable considerations but depend on subjective preference, so they don't belong in an objective ranking.