Most recipes provided by manufacturers produce a yield of one or two pints, depending on the capacity of the machine. To produce our two bases for five times the yield of ice cream/sorbet for our tests, Karla quadrupled the batch of chocolate sorbet mix.
Making enough of the ice cream base was trickier, because it’s very difficult to get that much liquid to the right temperature to thicken well, then cool it down quickly before it overcooks and curdles.
Doing separate batches for each machine would not be fair, as any slight variation in the base texture could influence our judgment of each machine’s performance. So Karla made four separate batches of the original 1.5 pint yield recipe, quickly chilled each individually in ice baths, combined them into one large batch to ensure consistency of flavor and thickness. , chilled overnight, then split it into five portions to test each machine. Karla now owes a vacation and maybe some gems.
Following the machines (and recipe) instructions, we made sure to properly chill each batch in the refrigerator overnight, which is especially important for models that use pre-frozen cylinders. (Adding liquid that is not sufficiently chilled in these machines will result in incompletely frozen end products.) For the Ninja, we froze the two pint containers provided by the manufacturer with the liquid inside.
The next day, we cleaned all the surfaces in our kitchen and started the ice cream factory, revving, churning the machines and, in the Ninja’s case, violently attacking the mix. We first did the test with the sorbet.
Then, because the Cuisinart and Amazon Basics cylinders need to be cooled again before we can make another batch, we refrozen them, then broke down the kitchen again the next day and ran through the vanilla. We also timed each machine by how long it took to make both the sorbet and the ice cream.
We sampled the results as they came out of the machines, focusing on texture more than flavor (which, with identical ingredients, didn’t vary). The best machines produced a smooth, dense structure that we associate with “richness”. We resampled them 24 hours later, after freezing all the batches overnight, on the theory that you’ll probably want to make ice cream ahead of time and slowly eat the product of your labor on subsequent days.
We gave higher marks to machines that made ice cream that stayed smooth after spending a night in the freezer, without becoming grainy or forming ice crystals. We also considered ease of use and ease of cleaning in our rating.