Ever since our 2-year-old son, Angus, stopped breast-feeding, my wife and I have served him milk in sippy cups. Now and then, we leave one in the bottom of a bag or the back seat of our car, only to find the receptacle days—or, in several memorable cases, weeks—later, the contents curdled and foul. A run through the dishwasher takes care of the cup, but when there's a leak, we're tempted to declare Angus lactose-intolerant and put him on a strict water diet. (For the record, it's impossible to completely eliminate the odor of rancid milk from car upholstery.)
But I hear calcium is good for the bones. So after an especially nasty cleanup, I quelled the desire to deprive my son of milk from here on out and scoured the marketplace for a truly leakproof cup for kids.
Most modern sippy cups consist of three parts: the cup itself, a lid that screws on to the threaded top, and a plastic or rubber valve that fits on the inside of the lid and controls the flow of both the liquid going out and the air coming in. Beyond this basic design, however, there's plenty of variation.
To start, I surveyed a bunch of experts—namely, the parents of young children—to find out what mattered to them most when shopping for sippy cups. By a long shot, leakproofness was the top concern. Second on the list was ease of care and assembly. A close third was ease of use—both for the child and for the adult. Most of the parents also mentioned that the style and appearance of the sippy cup played some role in their decision.
My poll of 22 parents was split down the middle on the issue of bisphenol A, a chemical used in the production of some sippy cups. In certain conditions—say, after multiple runs through the dishwasher—BPA can leach out from the cup and seep into the drink it contains. Some parents were alarmed by a slew of recent studies that have shown the ingestion of BPA to be potentially dangerous. (As the Washington Post reported last year, BPA has been "linked to breast and prostate cancer, behavioral disorders and reproductive health problems in laboratory animals.") Other parents pointed out that BPA has been used in food containers for decades—seemingly without harm. Good point, but I decided to play it safe and test only BPA-free cups.
Next, I convened a small panel of parents and asked them to put a dozen or so half-filled sippy cups to the test. They gripped them, shook them, turned them upside down, dropped them on the floor, pulled them apart, put them back together, and even sipped from them. Keeping in mind their children's likes and dislikes, they evaluated each cup on the following criteria:
Leakproofness (20 points): It has to keep the milk in the cup.
Ease of care(12 points): The fewer parts to dissemble and reassemble, the better.
Ease of use(12 points): Is it easy to transport, hold, drink from, and refill?
Style (6 points): Was the cup designed with a child's visual sensibility in mind? Or does it look like it belongs in a hospital?
The results, from upholstery-wrecking to hermetically sealed:
TODAY IN SLATE
Slate Plus Early Read: The Self-Made Man
The story of America’s most pliable, pernicious, irrepressible myth.
Rehtaeh Parsons Was the Most Famous Victim in Canada. Now, Journalists Can’t Even Say Her Name.
Mitt Romney May Be Weighing a 2016 Run. That Would Be a Big Mistake.
Amazing Photos From Hong Kong’s Umbrella Revolution
Transparent Is the Fall’s Only Great New Show
Rehtaeh Parsons Was the Most Famous Victim in Canada
Now, journalists can't even say her name.
Lena Dunham, the Book
More shtick than honesty in Not That Kind of Girl.