Dry Shaking
So you've been shaking your cocktails and you're not getting fluffed up heads like you see at your favorite bar or on the Instagrams. Instead you get a waifish layer of bubbles with no staying power? You can't figure out what's so special about a fizz even though you gave yourself tennis elbow?
Well here's the deal. Water (a.k.a, dissolved ice) is necessary to create a foam. Too much water and you inhibit creating and sustaining a foam. Somehow, you have to balance appropriately chilling and diluting your drink while building a foam.
There are three options here:
- Just keep shaking. You tried that and you want something better. Your culprit here is probably too much dilution.
- Make an egg white meringue toupee. Why not whip up some egg white separately and just slap it on top? I reckon you could, but it wouldn't be very integrated with the rest of the drink. It would lack the fragrant nose of an incorporated egg white. And if you try to fold it into the drink in the vessel you're asking for trouble and half-ass integration. Not too mention that this is just inefficient - there are better ways!
- Only do some of the shake with the ice. Whoa ho! That's a great idea! So good, the cocktail spirits have divined us plebs with two techniques: dry shaking and reverse dry shaking.
I didn't name these but yeah, they both seem like appropriate names for a thing you do when playing one handed couch hockey.
With drink mixing, a normal shake is a wet shake. Not because you have liquid ingredients in your shaker, but because of the ice. The longer you shake, the wetter, or more dissolved, your ice gets. Exclude the ice and you have a set of ingredients that won't get more wet (more filters diluted) as you shake. Thus, the dry shakes.
In this article, we'll address the regular ol' dry shake. These two techniques are not equal, nor is one better. They are definitely situational. From my experience, dry shaking produces a great, foamy head. Reverse dry shaking gets more volume, which isn't always desired. So on to the dry shake!
Why dry shake
Typically, your foaming agent will be an egg white, but there are plenty of other options, from cream to pineapple juice to aquafaba. Anytime you see an egg white in a recipe, or another foaming agent, you should think about dry shaking.
What you’ll need
You’ll need a shaker or mixing tins. I prefer mixing tins, specifically 
How to dry shake
With a dry shake, you start by pouring your ingredients into the shaker, then you do not add ice. Keep the ice in the freezer. Now, if you're using shaking tins or a Boston shaker, you're going to seal your shaker differently than you normally do. With a regular shake, you tip the top part of the shaker at an angle which helps you to break the seal when you're done. That works great when you have ice in your shaker to suck that top down tight as the ingredients get chilly cold. Without ice, you will not get a strong seal and your shaker will leak and become messy. Solve that by aligning your shaker top straight up and down. It doesn't have to be perfect, but you'll get a better seal the closer the top's rim matches the inner, circular edge of the bottom.
Then you shake. Hold the shaker carefully to ensure the seal doesn't pop. Shake for 15 seconds and you should have a good head and texture. If you're making a fizz, shake longer.
Once you're done shaking, open up that shaker and add your ice. Seal it and shake for another 10-12 seconds to chill and dilute.
Crack it open, strain into a glass, and serve the drink. You'll have achieved a good head, but even then, it won't last forever, especially the texture within the drink that is under the foam.
So what's actually going on here?
When you shake a drink, you're forcing tiny air bubbles into your liquid. Normally these air bubbles pass through your liquid ingredients but do not stay in solution for long as there isn't anything to prevent their escape. If you've added a foaming agent, such as egg white, to your shaker, then you're able to change things. As the air bubbles move across the egg white proteins, the air bubbles become trapped in the proteins as molecular bonds start to form. As the whipping continues, those proteins start to denature and unravel. Keep shaking and those proteins begin to form a matrix of foam around the air bubbles. Seems pretty simple right? The same principles at work also apply to ice cream, cake, and souffles (all foams), and to some extent butter and cheese.
So here's to your foamy head. Let it be thick, with itty bitty bubbles. May it last until your pal orders another!
If it doesn't, or if you want to go big, you can do the reverse dry shake, or try a few of my tips for foamier drinks.