Most recipes provided by the manufacturers produce one or two pints depending on the machine’s capacity. To produce our two bases for a yield of five times as much ice cream/sorbet for our evaluations, Karla made a quadrupled batch of the chocolate sorbet mix.
Making enough of the ice cream base was more complicated because it’s very difficult to get that much liquid to exactly the right temperature to thicken nicely and then cool it down rapidly before it overcooks and curdles.
Making separate batches for each machine would not be fair because any slight variable in base texture might influence our judgment of how each machine performed. So Karla made four separate batches of the original 1.5-pint-yield recipe, rapidly cooled each down individually in ice baths, combined them into one large batch to ensure consistency in flavor and thickness, cooled that overnight, then divided it into five portions to evaluate each machine.
As per the instructions for the machines (and the recipes), we made sure to chill each batch properly in the refrigerator overnight, which is especially important for the models that use frozen cylinders. (Adding liquid that isn’t sufficiently chilled in those machines will result in incompletely frozen final products.) For the Ninja, we froze the two manufacturer-provided pint containers with the liquid inside.
The next day, we cleared every surface in our kitchen and began the ice cream factory, getting the machines whirring, churning, and in the case of the Ninja, violently attacking the mix. We ran the evaluation with the sorbet first.
Then, because the cylinders for the Cuisinart had to be chilled again before we could fairly make another batch, we refroze them and then broke down the kitchen again the next day and ran through the vanilla. We timed each machine, too, for how long it took to make the sorbet and the ice cream.
We sampled the results right out of the machines, focusing on texture. The better machines delivered a smooth, dense structure that we associated with “richness.” We tasted them again 24 hours later, after freezing all batches overnight, on the theory that you’re likely to want to make ice cream in advance and slowly eat the product of your labor in subsequent days.
We gave higher marks to machines that made ice cream that remained smooth after spending a night in the freezer, without becoming grainy or forming ice crystals. We also factored ease of use and ease of cleaning into our evaluation.
