Here's one fun use: replacing egg whites in shaken cocktails. Particularly useful for vegan friends (or anyone who feels squeamish about raw egg as an ingredient).
As long as you have good shaking technique, the foam and mouthfeel get pretty close to egg-based methods.
> or anyone who feels squeamish about raw egg as an ingredient
I still use chickpea juice in cocktails to mix it up. But the chance of a salmonella poisoning from eggs in the modern US supply chain is astronomically low. You're at much higher risk from most produce.
If you're really risk-averse, you can always sous vide your eggs at 132 F for 60 minutes. This will pasteurize the surface (where any bacteria live), yet preserve the raw egg texture. (Egg whites and yols typically don't change form until around 140 F)
In my experience it's not people that are worried about getting sick. It's that they just don't like eggs that much and raw eggs are even worse. So the idea of plopping an egg white into a delicious whiskey sour makes them want to gag.
I have one convert so far, but he didn't see me make the drinks, just the final result.
I'll have to try chickpea juice though since it seems logistically easier than dealing with an egg for a drink.
Being from Europe I actually wondered how much of a difference there can be between US and EU when it comes to that issue, and this[0] StackExchange message was particularly interesting to see EU cases being much more prevalent than US ones.
I grew up with unwashed eggs and never gave it much thought, but now I guess that's one more thing to keep in mind (although I live in North America these days)
Somehow a little (probably incorrect) part of me likes to think that the unwashed eggs are more "authentic" and lead to better food - it's not rational thinking at all, and I'm not waiting for salmonella to hit me before I work at changing my mind about that :)
The big downside with washed eggs is the shelf life from what I understand, I happily keep unwashed eggs at room temp for ~a month, whereas I from what I understand eggs in the USA would need to be refrigerated and still wouldn't keep as long.
I get 3 weeks with my (refrigerated, American) eggs no problem. I think our American fridges probably tend to be larger than European ones, so space in it isn't at a premium.
The one thing I'd love to see however is whether we'd find the same proportions of nutrients in a more scientific breakdown too. Humans aren't necessarily able to know purely from the experience itself if something is healthier than something else for them, we're more wired to detect if something is problematic or not and also prone to a whole lot of suggestion. While the tasting test seems to show that the immediate experience isn't conclusively discernible, it doesn't tell us anything about long-term health effects (understandably so, they're not egg-researchers dedicating decade-long funding to figure that one out!).
In the UK eggs are unwashed and unrefrigerated by law, but as that other StackExchange answer says, eggs sold in supermarkets are all from vaccinated chickens, so salmonella from eggs is basically non-existent. The NHS even says it's fine for pregnant women to eat raw eggs.
> or anyone who feels squeamish about raw egg as an ingredient
I'm weird but I feel more squeamish about using the juice from a can of beans than I do using raw egg! Not because I think there's anything dangerous in there, just because it's unpleasant to me on some odd level :)
PSA: You don't want to eat uncooked soaked dried bean residue (especially red kidney beans). Uncooked it contains phytohaemagglutinin (plant lectin) which is toxic to humans. After cooking via boiling or pressure cooking it reduces the toxin to safe levels. Do not slow cook.
Acidic foods are not good for metal. Also, there's the possibility of metallic taste being transferred to the food so cans are often lined with plastic.
It's actually a far superior mouthfeel! The eggwhite foam can have a texture that's hard to describe...dry? coarse? But the aquafaba is smooth (and no, no chickpea taste even though I was pretty worried about that the first time I tried).
In my experience, egg white foams are thicker and more stable than those made with aquafaba, and the egg white has a softening effect on booze. Whether this is desirable depends on the cocktail, the booze, and your personal preference. For instance, I don't think a whiskey sour tastes quite the same with aquafaba (it's a bit harsher and the flavors don't quite marry as well), but I don't notice a difference in a sour made with a clear spirit like pisco. On the other hand, I actually prefer aquafaba in a Ramos Gin Fizz; I find the egg white foam to be too thick, to the point where it just floats on top of the drink and you can't really sip through it.
Pro tip: Instead of doing a dry shake with the egg white, as is traditionally done, try blending it into the cocktail before adding ice. (I use an immersion blender for quicker setup and easier cleanup.) I've found the texture of the foam to be smoother if you do this.
Interesting, scary. My partner has peanut anaphylaxis, epipen, never once reacted to aquafaba which I used in hummous to loosen the mixture if there is enough lemon-juice sourness and it's too thick. We eat a LOT of chickpea. She's never had anything approaching throat constriction or mouth swelling.
From the little bit of reading I just did, it sounds like only some people with peanut allergies will also experience reactions to other legumes - my brother being one of the unlucky few. I do not believe it was contamination as it was behind a bar vs a kitchen, but no one knows for sure.
I've been doing a lot of cocktails lately (gee, wonder why). And I do enjoy a flip. I don't make them simply because I don't want to deal with leftover egg yolks. But I tend to throw away aquafaba. Next time I have it, I'll try a flip made with it.
Recipes for sweet things usually include some salt because it enhances the flavor. If you've got salty chickpea juice, just consider reducing the other salt.
Traditional whiskey sours (or any other "sour"), among other classic cocktails, are made using an egg white. When shaken well, it creates a foamy layer on top of the drink that is quite stable and offers a pleasant texture (IMO), somewhat similar to the foam you get on top of a freshly poured beer. On top of that, there is some sort of chemical reaction that happens with the egg and alcohol, especially oak-aged spirits—apparently the egg white "softens" the booze, which is nice for higher-proof whiskeys and such.[0]
You can take this even further, too: I make a variation of the Mai Tai that's topped with a foam made by blending egg white with passion fruit puree. The foam is the first thing you taste, so you immediately get hit with the sharp, sweet-tart flavor of the passion fruit, before the rest of the (more subtle) flavors kick in. It's delicious.
(I've done it with aquafaba and it works almost as well, although I've only used canned, which generally contains salt. I don't mind it, but it doesn't work in every cocktail.)
[0]: If you're interested in this stuff, I highly recommend the book Liquid Intelligence by Dave Arnold.
As long as you have good shaking technique, the foam and mouthfeel get pretty close to egg-based methods.