Does the blender harm the collagen? I vaguely remember hearing Dave say he stirs it in at the end but I'm not sure...
I blend it at the end on slow speed for around 5 seconds
I blend mine. I'm not sure it's the most optimal way to do it, but it saves me time when adding it to stuff like smoothies. On the other hand, if I'm making a hot drink, I stir it in.
"I know how to despise mere cool intelligence. What I want is intelligence matched by pure, physical existence, like a statue." --Yukio Mishima
Let's be friends on MyFitnessPal!
Blend the crap out of your coffee + butter and oils. I've heard Dave say 1-2 minutes, but I personally think that's a bit ridiculous. I usually blend mine for 15-20 seconds, which seems like a long time to me (and my blender is LOUD). Longer blending will help micellize the fats for better absorption, in theory.
Then add the collagen, only blend for a few seconds. When I do that I usually just blend for 1 second so that everything mixes up properly. Or I'll put the collagen in my coffee cup and then pour the blended coffee into the cup - the pouring causes everything to be mixed up (mostly).
Blending for long periods can POTENTIALLY damage proteins, whether it's collagen powder or any other protein shake. I don't know how much could be damaged in 20 seconds... but since it's such a small adjustment to behavior to avoid the potential risk - I blend in two steps.