Pick up a chef's knife and try to slice a crusty sourdough. The blade skids across the crust, then dives through and squashes the crumb underneath. Now try a serrated bread knife and the same loaf gives up clean, even slices with almost no downward pressure. The difference is not sharpness. It is geometry, and the geometry most bread knives use today was worked out in Solingen, Germany, by Franz Güde in the 1930s.

This post covers how a serrated edge actually cuts, what makes the Güde version different from the scalloped edge on most bread knives, and how to choose the right length and handle for the way you bake and cook.

How a serrated edge cuts

A plain edge cuts by pressing a very thin wedge through the food. That works when the surface is soft enough to let the wedge in. A hard crust is not; it resists, the blade slides sideways, and by the time it breaks through, all the force you applied goes into the soft interior.

A serrated edge solves this by touching the crust at only a few points. Each tooth carries the full pressure of your hand on a tiny area, so it punctures the crust instead of sliding on it. Between the teeth, the recessed cutting edges are protected from the crust and stay keen for years. As you draw the knife back and forth, the teeth open the crust and the recessed edges slice the crumb. Little downward force is needed, which is why a good bread knife leaves a loaf's interior intact rather than compressed.

The same logic applies to anything with a hard skin and a soft interior: tomatoes, roasted squash, a crackling pork roast, a layered cake with a crisp top.

What Franz Güde changed

Serrated blades existed before Güde. What Franz Güde, son of founder Karl Güde, developed in the 1930s was the pointed-tooth serration: instead of rounded scallops, the edge is ground into sharp, pointed teeth with a recessed cutting edge set back behind them. The pointed tips bite into crust immediately, and because the cutting edge is set back, it never rubs on the board. Güde also introduced the back-set serration, in which the serrated section is ground so that the teeth work as the blade is drawn rather than pushed.

The manufactory still grinds this edge by hand in Solingen. Each Güde blade is drop-forged from a single bar of chrome-vanadium-molybdenum steel, ice-hardened, and passes through more than 40 manual operations before it is sharpened. The serration is not stamped or machine-scalloped; it is ground tooth by tooth, which is why a Güde bread knife's teeth are uniform along the whole blade and why the edge stays effective for a very long time without resharpening.

Why length matters more than you think

The most common mistake with a bread knife is buying one that is too short. A blade shorter than the loaf forces you to saw in several passes, and each pass tears a little.

• 8 inches (21 cm) handles baguettes, sandwich loaves and rolls. It is the size that fits most knife blocks and drawers.
• 10 to 10.5 inches (26 cm) covers most home-baked boules and bâtards in a single stroke and is the length most bakers settle on.
• 12 inches (32 cm) is the Franz Güde bread knife, the model the series is named for, also offered in the Alpha and SYNCHROS series. Its width and length let it walk through a large sourdough or a rye loaf in one or two draws, and the broad blade doubles as a server.

If you bake, or buy whole loaves from a bakery rather than pre-sliced bread, go longer than you think you need.

Choosing a handle

Every Güde bread knife carries the same forged blade and hand-ground edge. The series differ in the handle, and the handle decides how you care for the knife.

The Alpha series uses Hostaform, an acetal resin that is dishwasher-safe and unaffected by moisture, which makes it the practical choice for a knife that is used every morning. The Alpha Olive and Alpha Pear series use oiled fruitwood; Delta uses grenadilla, introduced for the manufactory's 2010 centenary; Barrel Oak handles are cut from wine-barrel staves more than 100 years old; the Franz Güde series carries an olive wood handle on its high-carbon blade; the bolsterless SYNCHROS uses smoked oak. All of the wood-handled knives are hand-wash only. The all-metal Kappa is seamless, dishwasher-safe, and was awarded a Red Dot for its design.

For a household that runs the dishwasher daily, Alpha or Kappa. For anyone who wants the knife to age with the kitchen, one of the wood series, wiped dry after use.

Caring for a serrated edge

A serrated edge needs less attention than a plain one, but not none. Wash it by hand with warm water and a soft cloth, dry it at once, and store it in a block, on a magnetic strip, or in a blade guard rather than loose in a drawer where the teeth can chip against other metal. Do not run a serrated blade over a sharpening steel; the steel is for plain edges. When a Güde serrated edge does eventually dull, after many years, a professional sharpener with a tapered ceramic rod can restore each tooth.

The short version

A serrated bread knife cuts crust by puncturing it rather than pushing through it, which keeps the crumb whole. The pointed-tooth edge on a Güde knife is the version Franz Güde developed in Solingen in the 1930s, hand-ground on a forged blade that will outlast most kitchens. Choose a blade at least as long as the loaves you cut, and choose the handle by how you wash your knives.

Browse the full range of Güde bread knives, from the 8-inch Alpha to the 12-inch Franz Güde, at Güde Shop USA. Orders over $69.95 ship free within the United States, and every knife carries a limited lifetime warranty.