Lasagna – Pasticcio vs Lasagna: Differences and Similarities

Like Bob said, surely boiling some noodles is way less of a bother than breaking out the pasta machine?

If you really want to make fresh pasta, I don't see any reason you couldn't use it for lasagna without boiling it - the reason one boils dry noodles is because it's hard to get them to soften in the time it takes to bake the lasagna. But just like when cooking fresh noodles, you need to be careful not to overcook it, so make sure all your fillings are fully cooked before you start layering. It also should be perfectly fine to not cut the noodles into strips - the reason dried noodles come that way is for easier handling.

It is possible to make lasagna using dried lasagna noodles without boiling them first, but you need to add more water and bake it longer. A search for "no-boil lasagna" will turn up scores of recipes.

Scum is the correct answer here, even though it sounds strange to modern ears. Originally, it is a cooking term, which denotes the stuff which floats on something you cook (protein in stock, the foamy stuff in jam) and can be gathered and removed with a skimming spoon if one wants to.

The derogatory use is more common in general conversation, and it is related, it probably arose as a metaphor. But in cooking jargon, it clearly has this meaning. It does have a little bit of a negative association, in the sense that you want to remove that scum, but I think there is no purely neutral word for it, since people who care about this kind of detail usually prefer it gone.