After the Craft Day ice cream came out closer to sorbet, Pamala was motivated to do some reading about milk, cream and half & half online; she pointed me to this list of dairy products and their fat content.

The blackberry ice cream recipe calls for 2½ cups of heavy cream and 1¼ cups of milk (unspecified type). This yields a mixture that’s 23-26% milkfat. We used half & half alone, which is just 12% milkfat. That definitely explains why our ice cream was more like sorbet. Definitely not a failure, but lesson learned.