Why shouldn’t I consume mixed Collagen Powder if left longer than 4 hours?Updated 7 months ago

This is because it can tend to get too thick and clumpy, and also to separate. Over time collagen protein in the solution will start to denature (which occurs when proteins unravel and lose their structure) and there is also a slight risk that microbes that may have been introduced from other ingredients or surfaces, could start growing. Refrigerating your shake will help preserve the structure of the protein, preventing unwanted clumping or separation, and also slow down the growth of any microbes. Freezing will stop any micro growth and preserve the structure of the protein for a much longer period. If you're cooking with collagen powder, you don't need to worry about this.