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The Science of Jello Shots
[Photograph: George M. Groutas]
Almost everyone has had a bad experience with those brightly colored jello shots synonymous with bad booze and worse ideas. But modern mixologists have reimagined these slurpable solids, creating new textures and beautiful presentations. Are they worth revisiting?
First, the basics
Why do jello shots get such a bad rap? Because it's just so easy to use cheap hooch and handy powdered mixes to make them. The sugar in these mixes helps to mask the taste of alcohol, and when you tie alcohol up in solid form, it doesn't dissolve as much on your tongue, which means you can't taste the alcohol as much. That means that you can easily get a little too drunk without realizing it.
What makes Jell-O or other gelatin turn into a solid? Well, technically, they aren't solids—they're gels. And gels are neither solid nor liquid: actually, they're both. As my friend Naveen Sinha, former head teaching fellow of Harvard's Science and Cooking Class explains:
"A gel is a material that is mostly liquid by weight, but behaves like a solid. Adding really long molecules, called polymers, or really small particles, called colloids, to a liquid can thicken it. By causing the polymers and colloids to stick together—a process called cross-linking—they can no longer flow past each other, so the liquid behaves like a solid."
In jello shots, the liquid portion is water and alcohol, while gelatin provides the polymers and colloids needed for structure.
What is gelatin, exactly? Gelatin is derived from collagen, a tough, flexible protein that plays a primary role in all of an animal's connective and protective tissues, including tendons and ligaments, skin, and bones. Heat it in the presence of water, and you get gelatin, a material that is equally versatile, with applications in everything from panna cotta to body armor.
What you really want to know: How to make ridiculously strong jello shots
First, let me skip straight to an important takeaway: extra-strong jello shots are just plain nasty and there's almost no good reason to make them.
So why am I explaining how to make jello shots stronger? Because understanding the limits of what's possible helps make you a more informed cook.
First, know your bloom strength. The water-binding power of gelatin is measured in something called bloom. The term sounds like it has something to do with "blooming" gelatin in water, but it actually is named for a scientist named Oscar T. Bloom who developed a test for measuring the strength of gels. Weaker gelatin might get a lower bloom rating around 50 while a bloom of 200 is considered pretty strong. As David Lebovitz shares, standard grocery-store Knox brand gelatin is plenty strong, clocking in at 225 bloom. To make strong gels, make sure to use strong gelatin. If bloom strength isn't listed on your generic gelatin, that may be the source of gelling problems.
Hydrate in two steps. To make strong gels, you're going to need every ounce of gelling power in your gelatin. Powdered gelatin comes comes in tiny granules that have to be filled with water before their polymers and colloids will spread out and cross-link into a gel. To hydrate gelatin, first let it sit in some warm water until you have a slurry. This first step ensures that no dry gelatin gets trapped within a protective outer bubble of hydrated gelatin. Then heat the slurry until the whole thing turns into a thick liquid of even consistency.
Yes, if you boil the gelatin in water for enough time, it will eventually hydrate and you can skip the slurry step. The hydration step helps for recipes when you don't want to bring your liquid to a full boil.
That's great, but how about some exact recipes and ratios? You know I love you and I would gladly
waste invest gallons of vodka and exhaust my pantry of gelatin in the name of developing the perfect jello shot. Luckily, though, other enterprising scientists have already tested every imaginable jelly shot strength and documented their results in meticulous detail.
Their key takeaways:
- A standard recipe made with 3 ounces of Jell-O powder calls for 5 ounces of 80-proof vodka and 11 ounces of water, but this results in a shot that tastes watered-down.
- To make a stronger shot, use just 4 ounces of water and between 8 and 14 ounces of vodka (to taste)
- A shot will gel at even higher alcohol concentrations, but taste and texture will suffer.
Improving Your Jello Shots
If extra-strong jello shots are crappy, is there any way to make ones worth drink-eating?
The structure and mouthfeel of gelatin depends on the crosslinking of polymers and colloids to form a gel. As it turns out, you can create a huge range of textures and mouthfeels by using different gelling agents.
For example, to make vegetarian/vegan jelly shots, you can use agar-agar, a seaweed-derived gelling agent often used in Asian candies. Unfortunately, agar has more "crumble" and less "chewiness" than traditional gelatin. And that's not a subjective statement—scientists actually measure this stuff (see fig. 5).
Digging through our archives, I found out we've already played with recipes from the Jelly Shot Test Kitchen—a book that creates beautiful and delicious jellies using just plain-old gelatin. The beautiful image above (of Pimm's No.1 jelly shots) comes from that book.
To take texture up to eleven, though, requires some special ingredients.
These carbonated Mojito spheres are thickened with a corn-based thickener called xanthan gum often used in gluten free-cooking. The gellified outer coat is created using sodium alginate, a seaweed-derived gelling agent. Inside, a totally liquid cocktail awaits. It bursts open when you bite down on the sphere.
The original idea is credited to Chef Jose Andres of Minibar (and more relevant to our discussion, Barmini) and was recreated by the team at Molecular Recipes.
Molecular Recipes also documents this recipe for pisco sour marshmallows from famed author/pastry chef David Lebovitz. The recipe does use gelatin as a gelling agent, but also incorporates corn syrup and egg whites to give the finished product that puffy texture. But, be careful: although the original recipe claims that much of the alcohol boils off during the cooking process, the network of corn syrups and egg whites used for the marshmallows may inhibit evaporation, so I suspect a good bit of alcohol remains. Either way, they look delicious.
And here's one last fun variation on jello shots: these whisky gums do use gelatin for structure, but the addition of corn syrup makes the candies chewable and helps them stay intact at room temperature.
So, are jello shots worth giving another... shot? What's the best jello shot or gellified cocktail you've ever tried?
About the author:Kevin Liu likes to drink science and study cocktails. Wait, that's backward. Ask him geeky food and booze questions on twitter @kevinkliu. While you're at it, check out his book about cocktail science.