Building a high protein pasta sauce sounds like a formulation footnote until you try it, because protein and simmered tomato sauce don't naturally get along. Protein powders and isolates tend to fight a sauce's texture: whey can seize or form a skin under sustained heat, isolates can turn a smooth sauce grainy or chalky, and some proteins shift color or turn a bright marinara dull. Then there's flavor — most people know the taste of "protein powder" the instant it shows up somewhere it doesn't belong, and a red sauce is an unforgiving place to hide it.
Acid compounds the problem. Tomato sauce is naturally acidic, and acid plus sustained heat is exactly the environment that can cause certain proteins to denature unpredictably — clumping, separating, or breaking the sauce's consistency instead of staying suspended in it. Solving for 20 grams a jar means choosing protein sources that are heat- and acid-stable to begin with, which is a real part of why collagen and bone broth work here: both have a long culinary history of being simmered, reduced, and cooked into sauces and stocks without falling apart.
The rest is ratio and balance — enough protein to hit a meaningful gram count without pushing the sauce toward pudding-thick, and enough attention to salt and acid that nothing curdles or separates on the stovetop or in the jar. Getting there isn't a single decision, it's iteration — testing how much of each protein a sauce can hold before viscosity changes, at what temperature and cook time proteins start to behave badly, and how salt and acid levels interact with each addition. A version that hits 20 grams of protein but breaks on reheating, or separates after a day in the fridge, doesn't count as solved. The bar is a sauce that behaves like sauce, every time it's heated, not just on the first try in a test kitchen.
It's a genuine food-science problem, not a marketing one: most attempts to add protein to a sauce make the sauce worse before anyone worries about whether it makes the eater healthier.