Wasn’t me but it’s a popular thing to do.
In fact last trip to the store I got some frozen concentrate to experiment with but haven’t yet.
I’m very, very,very leery of bottle bombs...
The FReeper mentioned he mixed three cans of the frozen concentrate with water to make a gallon then mixed it into his five gallons of cider. I wanted to ask why he didn’t just add the defrosted concentrate to his five gallons of cider? I bought some concentrate but am not expecting to add it in for a few months. I will bottle in PET bottles.