It's funny that I was thinking about the issue today. Specially talking about proteins and how they can be countable and uncountable actually meaning different things.
1) There aren't many proteins
2) There isn't much protein
1) means that there aren't many different kinds of proteins. Let's say only protein A and B, but you can have a ton of each.
2) means that the total amount of protein (regardless of variety) is low, i.e. you can have proteins A through Z but the total amount is little.
What about 1 spoonfull or 2 spoonfulls? or spoons-full?
On the other hand I was thinking about plural forms of different drinks. Maragaritas are easy, but what about Tequila Sunrise or Sex on the Beach?