siegfriedw, I bought my CHR Hansen Brand of
powdered crystallized rennet off of eBay USA. I don't know the lineage or how well it was stored so I won't buy it off of eBay again, and actually I've never seen it on eBay since. I did contact CHR Hansen and they said they only sell small retail size packages in the Brazil market, so that could be where it came from.
As far as I've seen, I think I'm the only one here using powdered crystallized rennet, most use liquid and I have no idea of the advantages/disadvantages.
That said I did notice that Austrian rennet maker
Hundsbichler makes dried powdered product called BioRen. Details page says it's particularly good for long aged cheeses as 97% chymosin.
Also, there is a post here about
Valirin brand powdered rennet.