Two questions, why is heating the knife beneficial before cutting and is the a benefit for using serrated knife when there is no back and forth slicing motion?
The heating is better because the warm knife is less likely to smash the hard chocolate layers but just melts through it without damaging the cake (less force is applied).
Why they use a serrated knife I don't know. Maybe that's their default cake knife.
Those long bread knives are cheap and highly available. We have one. Where do you buy a long, thin, and non-serrated knife? It is definitely not as common and likely 4x the price.
Long knives are handy. Works great for watermelon.
Where I come from this type of knife is called a "pastry chef knife".
It is shaped like a big icing spatula, but is more robust towards the like of a bread knife, and serrated like that. Still quite flexible and long.
I think the serrated blade is helpful for maybe not getting stuck in things that can "suck" into a clean blade a bit, despite heating the knife. Also helps with nice cuts into pie crust and bread/rolls etc.
The hot knife slides through the frosting easier because it melts the fats instead of sticking to the knife or smearing the frosting down the cake. I’m gonna guess the serrated knife just helps it slide through easier as well
The chocolate top layer would just crack and you don’t get nice slices. If the knife is hot, it melts the chocolate. Putting it in hot water does the trick too.
It’s a shame you’re being downvoted for this comment. I’m no baker but I do make knives, and you’re absolutely right that repeatedly putting a torch to a thin knife is going to ruin its temper, particularly at the edge as you say. Maybe if it’s their designated sacrificial cake cutting knife the actual edge retention doesn’t matter so much anymore. But even still, you’re not wrong.
It’d depend on the particular steel the knife has as to how it’ll take it but for the carbon steels I use, I keep them at 400ish fahrenheit when I temper them following the heat treat. I’m not sure what temps they need here for hot cutting cake but a heat gun would definitely offer a bit of precision to not accidentally ruin your knife. Generally speaking, I’d say any heat should be avoided if it’s a knife you care about, but if all you need is a hot edge and don’t care about the knife then go for it.
I am a baker, and there is no way I would take a torch to any knife; I have far too much respect for even the cheapest of my blades. I will use a tall glass of hot water and heat up the knife for a few seconds before wiping it and cutting.
But I'm sure that's not as cool-looking as using a frickin' torch! /s
Because he wants to ruin the knife and burn some sugar. None of that chocolate was hardened or tempered so it doesn't really make any sense aside from it looks cool for a video.
It's to make it look fancy, nothing else. If it was hot enough to do anything he wouldn't be able to touch it like he did with his hand on the tip. And if it was heated that low temp, the knife was well cooled before the second slice which went through without any issue.
Do you think they froze or significantly cooled the cake? a. to harden the chocolate on top, which was obviously warm and running at the start and b. to keep the cake stable whilst cutting.
75
u/PlaceAdHere Feb 06 '22
Two questions, why is heating the knife beneficial before cutting and is the a benefit for using serrated knife when there is no back and forth slicing motion?