A good bread knife for sourdough has a serrated blade about 10 in long, at least 2 in longer than the loaf is wide, so it can saw through a hard crust in long strokes without crushing the crumb. Wavy (scalloped) serrations cut cleanly and last; pointed ones bite hard crust faster.
Our pick: a 10 in wavy-edged bread knife such as the Mercer Millennia. Large boules over 9 in: a 10.25 to 12 in blade. Uneven slices? A slicing guide helps more than a new knife.
Best for most bakers
10 in wavy-edge blade
A long, wide wavy-edged blade with a grippy handle; used in many restaurant kitchens.
Hard-crust sourdough
10.2 in wavy-edge blade
A light 10.2 in wavy-edge blade that Victorinox says can go in the dishwasher; the rounded tip doubles as a spatula.
A long, thin Japanese blade for large boules and clean, thin slices.
Even slices
Adjustable slice width
Guides the knife straight for even sandwich slices.
How we know: weights and sizes are the makers' published figures, linked from each product page, and a dough range marked “our estimate” is our arithmetic on them. We do not perform hands-on testing. How we compare.
A knife needs to reach across the loaf with room to saw. A 900 g boule is usually 8 to 9 in across, so a 10 in blade is the minimum that slices it in full strokes. A shorter knife forces short, pressing strokes that tear the crumb. See how to slice sourdough.
Wavy (scalloped) serrations glide and leave fewer crumbs; they stay sharp for years because the points are rounded. Pointed serrations bite into a hard crust faster but can tear soft bread. For sourdough, either works; wavy is the safer all-round choice.
A taller blade or an offset handle keeps your knuckles off the board on the last cut. Check the handle is grippy when floury. For a left-handed baker, a symmetric serration (most wavy edges) cuts straighter than a one-sided one.
Hand wash and dry it at once; the dishwasher dulls and loosens handles. Store it in a sheath, block or on a magnetic strip, not loose in a drawer, and keep the loaf in a bread box or bag. Serrated knives stay sharp for years; when one finally drags, a sharpening service or a tapered ceramic rod restores it.
At least 10 in for a typical 8 to 9 in boule; 10.25 to 12 in for larger loaves.
Wavy serrations cut cleanly and stay sharp longer; pointed ones start through hard crust a little faster. Both suit sourdough.
Yes, with a tapered ceramic rod that fits each serration, or a professional sharpening service.
Keep what you own when it does the job. These are the other exact models we profile.
A serrated bread knife made by Thermohauser and sold by Central Milling, 15 in long overall with a plastic handle, short enough for a standard drawer.
