Why It Works
- High concentrations of milkfat and sugar interfere with ice crystal formation and keep the texture creamy and smooth.
- A combination of large and small cookie crumbs along with fresh lime zest adds color and texture.
- The popsicle-in-a-bag formula makes it ideal for eating on the go or packing in a cooler.
Growing up in Ohio, I never had the good fortune to try a boli―a large Mexican ice pop encased in a clear plastic bag—when I was a kid. For me, cold treats came in a pint at the grocery store or from a Dairy Queen. But for my partner, who is Mexican, Dairy Queen and similar fast food chains that peddled frozen desserts were something special. When he would ask for American soft-serve, his parents gave him a boli: a small let-down at the time, but now a nostalgic reminder of his childhood.
Where we now live in steamy Mazatlán, Sinaloa, frozen treats are plentiful: there’s traditional nieve de garrafa, hand-churned ice creams and sorbets with flavors like leche quemada (cooked milk), passionfruit, and sweet corn; paletas (popsicles); and bolis, creamy milk- or fruity water-based ice pops frozen inside neat plastic bags. This recipe is for one of my favorite milk bolis (also known as bolis de leche), key lime pie. It’s tangy, creamy, and sweet, and tastes just like the classic pie.
Making the bolis is relatively straightforward: I process whole milk, sweetened condensed milk, cream cheese, and sugar in a blender. The condensed milk helps produce that classic key lime pie flavor, while the addition of whole milk and cream cheese increases the milk fat content of the mixture, which inhibits the formation of ice crystals and keeps the texture smooth and soft. For the limes, I tested with both key limes and Persian limes and found that, in terms of flavor, they're not that different. My hypothesis is that the frozen boli is so cold that the slight flavor difference and the variation in acidity isn't that noticeable. I suggest you use whatever is available to you that’s of good quality. Just make sure to dial back the amount of zest if you’re using Persian limes so that it doesn’t overwhelm the other flavors.
One of the most alluring aspects of bolis is the thought and creativity that some people put into the experience of eating them. For ones flavored with jocote (a small, acidic fruit with a plum-like flavor, sometimes known as ciruela), you might find a stone with some of the tart fruit still attached at the bottom of your boli, perfect for chasing the sweetness. A mango boli may have a swirl of spicy red chamoy sauce that you can mix with the fruit or enjoy as a burst of intensity at the end. Then, there are milk bolis that reveal pieces of cookies or Gansitos, a chocolate-dipped snack cake, as you eat them.
For this recipe, I tried to incorporate some interesting textural elements. My early attempts to incorporate small segments of key lime or candied lime slices fell flat: the former were too intense and the latter were too large and tough to chew. Instead, I settled on incorporating galletas Marías (crisp vanilla cookies that can be found in Latin markets), broken into various sizes, and lime zest. To get the cookie’s flavor into the boli, I blend a few cookies at the end, along with the zest. Then, for larger cookie chunks and more texture, I like to add broken up galletas Marías directly to each boli bag. The result is an ice cream-like treat with pockets of tender, cream-soaked cookies.
When it’s time to freeze the bolis, you’ll need plastic boli bags. Searching for “boli bags” or “ice pop bags” will turn up a number of options you can order online, but it’s worth checking your local Latin supermarket first. I used 2 3/4- by 10-inch bags, which is a standard boli size. Once you have the bags, then comes the tricky part: getting the viscous mixture into a flimsy plastic bag. The method that works best for me is to prop the boli bag up in a cup, hold the mouth of the bag open with one hand, and very slowly pour in the mixture with the other hand. The bag will settle and move slightly as it fills up, and pouring slowly means you can stop the flow if the bag falls over or closes iin on itself. Fill each bag up about halfway, then gently mush the bottom of the bag around so that the larger cookie chunks incorporate into the mix and aren’t left dry at the bottom, pinch the bag close at the fill level to get the air out, and tie a quick overhand knot to seal it off.
Once your bolis are frozen, bite or cut off a corner of a boli bag and dig in. You might have to gently bite through the bag to extract the first bits of the boli, but as it softens, you can start to squeeze it out of the bag. If you’re new to bolis, it'll take a little experimentation, but you'll figure it out.