The Science Behind Why Your Cocktail Shaker Always Seems To Get Stuck
No home bar is complete without a proper cocktail shaker. There are plenty of cocktails that are better stirred rather than shaken (sorry Mr. Bond, but that includes martinis). When the time comes to craft a perfectly shaken cocktail, however, you'll be glad to have one on hand.
Anyone who's tried out a cocktail shaker before knows that one of their most frustrating qualities is that they tend to get stuck. There are multiple reasons for this, but the simplest explanation is that it gets stuck because of the cold. Whether you're using a Boston or cobbler shaker when making your cocktail, it's likely that it will get stuck due to the change in temperature. This is ironic since one of the reasons for shaking the cocktail in the first place is to reduce its temperature. However, this rapid change in temperature does create an actual vacuum seal. So it's important to remove it carefully – or you might end up worse off than when you began.
Why your cocktail shaker gets stuck
One of the simplest reasons that your cocktail shakers may be sticking is the contents that are inside. The rule of thumb for when to shake a cocktail is when your drink contains citrus. The vigorous shake breaks down more of the citrus' aromatic compounds and tends to make for a more mellow drink. Unfortunately, citrus is often sticky — and when paired with simple syrup it may cause things to seal up.
The other reason is the rapid change in temperature. Whenever you shake a cocktail with ice, you're not only cooling the drink but the air that's trapped inside the shaker as well. This means that the air molecules will start to condense as they cool and create an actual vacuum inside of your shaker. On top of this, the metal of the shaker will contract as well. This means that the pieces will form together more tightly as the drink cools. It's one of the reasons why Boston shakers are able to stay together so effectively, and bartenders don't seem worried about anything spilling out until they've given it a careful bump to break that seal.
If you aren't an experienced bartender though, you might still be struggling to master this magical unlocking technique. Thankfully, it's not that hard to learn.
How to unstick your cocktail shakers
The first step to unlocking a cocktail shaker is to make sure you sealed your cups together correctly. To do this, you need to create a (more-or-less) straight vertical line on one side with both cups of a Boston shaker. That means that even though the top cup will be slightly skewed when you tap or twist it down to create a seal, you should still be able to find the line on the side to indicate a proper seal.
Once you're done shaking your drink, position the shaker with the line closest to you. While gripping the bottom cup with your nondominant hand, tap the shaker where the two glasses meet with the heel of your other hand. It may take a couple tries to knock it loose, but it should do the trick. While you might be hesitant to wait around for the seal to weaken, this might not always be the answer. Frost can quickly build up on the outside of the shaker if it's left to sit for too long, and make getting it unstuck even more challenging. So don't delay, or you may make the problem worse than it already is.