Those gleaming knife sets spread out in alluring arcs in department store displays and catalogs have us enraptured — until we see the price tags. That instant "ouch!" we feel doesn’t require contact with a blade.

How many knives does a humble home cook need, anyway? And what kinds? How do you use them? Turns out these are common questions, and chef Grant Sato of Kapiolani Community College is the go-to guy when it comes to kitchen knives. His noncredit knife class, offered several times a year, is so popular that people practically camp out to sign up. (For information on the class, call chef Frank Gonzales, noncredit culinary coordinator, at 734-9441.)

For the benefit of those who can’t attend, Sato shares tips here about that most essential of kitchen tools. It turns out every kitchen requires just three types of knives.

Selecting a knife

In general, knife handles should correlate with hand size. Big hands might find big, blocky wooden handles most comfortable. Those with petite hands can improvise, using a 6-inch paring knife as a chef’s knife.

A key point to consider is weight: Does the knife feel heavy? If you can cut without tension, it’s fine. A guideline: The pressure when holding the handle of a knife should be the same pressure you use to hold a raw egg. (See "Slicing and Dicing Tips.")

"There’s no one knife for everyone," says Sato. "Find a knife that allows free range of motion so that it’s not burdensome to cook."

Blade thickness

The spine of a knife can tell you what it’s best used for.

A thick spine indicates a chopping knife, meaning the metal of the blade is wide enough that when the blade goes into the food, it causes it to snap. Think dicing carrots or chopping through bones.

A thin spine indicates a slicer, meaning the knife goes through the food with ease. There’s not much pushing apart of the food.

Knife handles

Sato calls the handle the most important part of a knife.

In fact, most knife companies make three lines of knives, and it’s not the blade that dictates price.

"The blades are all the same," Sato says. "It’s the material of the handles that are different."

Knife handles are usually made of polyurethane, wood and metal.

Polyurethane-handled knives are inexpensive, starting at 99 cents. They’re also useful for color-coding to avert cross-contamination of food.

But polyurethane handles are attached to the blade with epoxy that can loosen if the knife is left too close to a heat source. Also, the groove by the base of the blade, where the handle and metal meet, is wide, making it a receptacle for bacteria.

Polyurethane-handled knives last about five years.

Wood handles last a "generation" — about 20 years. Wood is not only a forgiving material that makes it easy on the hands, but it also has a natural antibacterial agent that hinders proliferation of germs. Prices start at about $30.

Metal handles are trendy, says Sato, but they’re impractical and pricey, costing hundreds of dollars. Because metal is a conductor of heat, knives left too close to heat can burn a hand; in cold climates they can be as chilly as an ice cube.

Some knife handles are shaped for left- or right-hand grips, making them comfortable but not universal.

Slicing and dicing tips

Handling a knife safely comes down to good technique.

» Technique starts with a good knife grip. Grab the handle of the knife with the last three fingers of your hand, then with the pointer and thumb, firmly hold the base of the blade. This anchors the knife and allows for flexibility in the wrist. The grip on the handle should be light, the same pressure used when holding a raw egg.

The other hand serves as a guide for the knife. Fingers should be placed perpendicular to the product and bent at the first joint, while the blade rests against the knuckles as the knife is moved in a rocking motion that goes down and forward, utilizing the natural curve of the knife.

The knife should never be raised higher than the knuckle. This prevents cutting the hand.

Place products near the heel of the knife. This enables you to cut with the flat portion of the knife for ease.

» When slicing vegetables with tough skin, such as cucumber, tomato or bell pepper, cut with the skin side down so the knife can easily and cleanly penetrate the food. Slicing skin side first can crush the flesh and shorten shelf life.

» To cut multiple items safely, do not stack. Stacking makes it easy for food to move and cause the fingers to slide under the knife. Rather, shingle pieces so each piece is anchored to the cutting board.

Sharpening your knife

Keeping knives in top shape requires two tools: a sharpening steel and a whetstone.

The steel is used to hone the knife; this maintenance should be done before every major cutting job, defined as cutting for more than 20 minutes.

To use the whetstone, move the knife against the stone (or vice versa) at a 45-degree angle with an even amount of pressure and strokes on both sides of the blade. Sato recommends doing three sets of three strokes on each side.

European knives are made of dense steel that is extremely difficult to sharpen on your own. It’s best to send these knives away for mechanical sharpening. The upside is that with honing, these blades can stay sharp for five to seven years.

Japanese and Chinese knives, in contrast, are made with high-carbon steel that is softer and thus well suited for the whetstone. These blades can stay sharp for three to five years with maintenance.

Selecting whetstones: Sharpening requires two whetstones of varying grades. For initial sharpening, run knives against a stone with a grit rated between 300 and 1,000 (the lower the number, the rougher the grit). Then, finish off the sharpening with a stone rated between 1,000 and 3,000.

Sanitizing your knives

Who knew that knives need to be sanitized? Turns out knives are no different from cutting boards or countertops. In fact, Sato says knives can cross-contaminate food, just as cutting boards do. One way around that is to use knives with colored polyurethane handles, to color-code the function of each knife (red for red meat, white for fruits and veggies, etc.).

Sato recommends two methods to sanitize: chemicals or heat.

"You can wash knives in a dishwasher that reaches 180 degrees or use a chemical sanitizer of 1 capful of Clorox to 1 gallon of water. Spray everything down with a water bottle or dunk a towel in the solution and wipe it down," he says. "It’s safe. The solution is lower than the chlorine in a swimming pool."