Soaking knives in the sink

After cooking, many people place cutting boards, dishes, pots, pans, silverware, and other utensils into a sink filled with soapy water for soaking. This practice diminishes the quality and effectiveness of knives, leading to corrosion, rust, and collisions with other items, which can cause chipping, scratching, or warping.

Knives with wooden handles or other absorbent materials, when soaked for too long, can swell, crack, and loosen the joint between the handle and the blade, potentially leading to complete damage.

The U.S. Consumer Product Safety Commission (CPSC) also warns that knives submerged in soapy water become difficult to see, increasing the risk of cuts when reaching into the sink.

Placing knives in the dishwasher

Renowned knife manufacturers Wüsthof and Zwilling J.A. Henckels advise against exposing knife blades to the dishwasher environment. Strong alkaline dishwasher powders or tablets, combined with high temperatures and water pressure, destroy the chromium oxide layer on stainless steel. This process promotes pitting corrosion, reduces sharpness, and causes rust, especially when chloride is present in the detergent.

The Culinary Institute of America (CIA), a culinary training organization in the U.S., also prohibits this practice due to the risk of mechanical collisions. Sharp knife blades can strike other utensils in the wash basket, causing damage.

Storing knives in a drawer with other utensils

Placing knives in a drawer alongside spoons, forks, and scissors causes blades to collide, leading to scratches, dents, and reduced quality. Experts from the American Culinary Federation (ACF) state that each time a drawer is opened and closed, knives can impact other metal objects dozens of times. Even minor collisions can chip a blade.

A test by knife sharpening expert Carter Fujiwara revealed that carbon steel knives stored loosely in a shared drawer developed dozens of small chips after three months, causing the knives to tear food instead of cutting smoothly.

Concurrently, according to the U.S. Consumer Product Safety Commission (CPSC), over 137,000 Americans annually require emergency treatment for kitchen knife cuts, with approximately 40% of these incidents occurring when users' hands come into contact with knives in a cluttered drawer.

Using the knife blade to scrape food

Many individuals use the knife blade to scrape food into a pan after chopping vegetables, a practice that can easily damage the knife. A blade is designed to cut in a vertical direction, where force is evenly distributed across both sides, ensuring durability. Scraping horizontally concentrates all force onto the thin blade edge, less than 0,1 mm, causing chips.

Research by The Cutlery and Allied Trades Research Association (CATRA) in the UK indicates that just 50-80 horizontal scrapes can reduce a knife's sharpness by 70%, equivalent to several thousands of normal cuts.

A test by American chef Chad Ward on Serious Eats demonstrated that a Shun knife used daily for scraping food required complete resharpening after four months. He advises that to maintain a knife's sharpness for five to ten years, one should only use the spine of the knife or a separate plastic or wooden scraper, avoiding the sharp edge for scraping.

Ngoc Ngan (Via Yahoo Life)