But to be honest, when I first read your question, I had a few immediate thoughts that didn’t have anything to do with infusing eggs with flavor through the shells.
My first thought was: what about aquafaba?
This is the water that’s left over when you strain a can of chickpeas, and most bars use aqua faba as a vegan or labor-saving alternative to real egg whites. You can use it in similar proportions to an egg white in cocktails, and it produces very similar effects, minus the initial viscosity.
But egg whites themselves are about 90% water, so whichever route you decide to go keep this one central rule in mind: water is known as “the universal solvent,” but it’s only good at dissolving and taking on the flavors of “water soluble compounds.”
This means that oils and certain volatile aromatics are not going to infuse well into a water- and protein-based media like aqua faba or egg whites. And that also goes for the oils in the lemon zest you grated into your egg whites, Danny. That’s why you had to do it in the moment, and plus, as you mentioned, you’ve got a textural issue now with all that lemon zest swimming around the foam in your drink.
Your best bets for flavoring egg whites are going to be hydrosols, like rose water or orange blossom water – which are created as bi-products of the essential oil making process. They’re more delicate than essential oils, but they are still extremely powerful, so use in moderation. Most popularly, we see the use of orange blossom water in the Ramos Gin Fizz – the one drink in the classic cocktail canon most notorious for its foamy head – so you can pretty much trust hydrosols for in-the-shaker infusion and possibly pre-service infusions into egg whites or aqua faba.
Otherwise, you can certainly mess around with infusing fresh herbs into your egg whites, and similarly, you could see what berries and non-acidic fruit will yield – but make sure you’re not dropping a whole bunch of acid into your protein-rich solution because that could have some unintended textural consequences when it comes time to make the drink.
In the end, Danny, egg whites are all about texture, which is why you see most people using infused spirits and outside hydrosols and flavor extracts to do the heavy lifting. It’s usually way easier and more effective to infuse your vodka with a handful of basil overnight than to try and balance both flavor and texture in egg whites.
I know this long-winded answer might not have been what you were hoping for, but the important thing is this: you saw an opportunity, you got curious and did some research, and you didn’t stop trying when no easy answer presented itself. This sort of curiosity and persistence is exactly what leads to breakthroughs in our industry, so just because infused egg whites are tricky and expensive to execute doesn’t mean there aren’t other frontiers out there. What about trying to color your egg whites? What about playing around with stencils so that you can create designs on the finished drinks? There’s a lot to do out there, and we hope you keep us posted with updates as you continue along your bartending journey.
Thanks for writing in.