I also start my custom foods with the type of food first, then a description, a brand and then what the serving size is that I'm doing. For example:
Sauce, Tomato and Basil, Newman's Own, 1/4 C or
Bread, Whole Wheat, Kroger, 1 slice
It makes finding things so much easier because like you said they stay grouped together. That being said, my list is also getting quite long and scrolling is still a pain. I would really love it if at the top of the page you could click on a letter of the alphabet and it would take you to the listings that start with that letter.
Just my 2 cents.