[Yardstick]

"Freezing food required cutting-edge technology in 17th Century England, so these ices were seen as great luxuries."

I'd like to know more about this cutting edge technology. How would they have frozen something in the 17th century apart from naturally occuring ice shipped in from somewhere and some salt. Did they have refrigeration of some sort back then?

[TheOldLady]

They didn’t have refrigeration, but they did know how to use insulation.

[Moonman62]

Putt the vessell that hath the chocolate in it, into a jaraffa (carafe) of snow stirred together with some salt

Salted snow.