knife to cut fresh/soft bagel
German serrated bread knife is not cutting too well. What should I get? Japanese? ceramic? I think "soft" bagel is "different" from hard bread.
Chances are your serrated knife is getting dull.
That said, I'd use a knife that is:
b) at least a bit longer than the bagel is wide
Any sharp 8+ inch chefs knife would do, though I prefer Japanese myself. I don't much care for ceramics due to the difficulty of sharpening them, their tendency to be short-ish, and their generally poor geometry, In any case, cut with a long but gentle stroke. If the knife is sharp enough, it will do the work for you without massacring the bagel.
I assume it is the same difference as soft bread vs hard crust bread.
What is the problem of using your German serrated bread knife? Do the bagels get torn/ripped apart or crushed/collapsed? What is the symptoms?
Chance is that your serrated bread knife is no longer sharp.
Do you have a sharp Chef's knife?
Try to use the tip of your Chef's knife to poke into your bagels and then start cutting. See if this help.
think of the method not the tool.
just cut the thing across the diameter and then split the U halves that balance on the board. ok so my lox is on several quarters rather than two circumferential halves, my world is over.
Like other have suggested, you want a knife that is sharp, thin, and longer than the diameter of the bagel. With really really soft bread, I find serrated knives tear more than cut--even when sharp.
It can be sharpened, though it is difficult and time consuming (you have to sharpen each individual "scoop" or "serration" which each change angles along the curve) and will inevitably result in the wearing down of the tips of the "teeth" of the serrations.
You could use a small spinning grinder (like a dremel with a special attachment) but this is pretty easy to mess up even for a skilled sharpener. A long, thin, conical rod coated in diamonds and mounted on a device spinning at a few hundred RPM would probably work pretty well once you got the technique down. Still, you'd run into many of the same problems as above.
I've done it before, but I'd be extremely hesitant to ever do it again. I sharpen knives for many of my friends and family, but always refuse to do sharpen serrated knives. Just not worth the effort.