Here's a discussion about a beer rinse:

It's a protein treatment. Just something else to try. I've tried it twice, though I feared for my hair smelling like beer and partially rinsed it out--my mistake. And it's easier than making the gelatin!
Wave Pattern: 2A
Hair Properties: Normal/Low Porosity, Medium Density, Medium Texture w/Fine Straight Underlayer
Co-wash: Suave Naturals, Cure Care
Low-poo: Renpure Brazilian Keratin
Rinse Out & Leave In: Tresemme Naturals
Gel: LA Looks Mega Mega Hold Gel, Garnier Fructis Spray Gel