Collins tells Inside South Florida he had no idea who the Rolling in the Deep singer was when he first heard she wanted to work with him, but he agreed to join her in the studio after hearing her voice.
The Against All Odds star says: "I've just started to work with Adele. She contacted me to write together. I wasn't actually too aware (of her). I live in a cave.
"She's achieved an incredible amount and I really love her voice and I love some of that stuff she's done. So, to me, it's always an eye-opener. Educational."
Reports suggest Adele has been recording new material since last April, after stepping out of the spotlight to become a mum.