You might recognize the words 'emulsified' or 'emulsification' from restaurant menus...but do you know what it really means, or if you do, the science of how it really works?
An emulsion is simply the combination of two substances that don't usually mix, or are naturally incompatible. If you'll recall from elementary school science, oil and water do not mix. This is because, first, oil is less dense than water and second because water molecules have a strong polar attraction to each other, whereas oil molecules are nonpolar. Breaking this molecular repulsion requires agitation (shaking, blending, whisking), which breaks the oil molecules into smaller bits that can be suspended in water. But this mixture is only a temporary emulsion (nerd alert: it's called a 'colloidal suspension'). For more lasting emulsions, we need an emulsifier…
Emulsifiers are agents like phospholipids or lecithin that straddle the divide between water-loving (hydrophilic) molecules, and fat-loving (hydrophobic) molecules. These emulsifiers can form bonds with both water and fat so they build a bridge between the two, encapsulating fat droplets to suspend them in water (or vice-versa) giving rise to the dreamy, creamy textures we love. Emulsification is the basis for some of the best things in food: aioli, whipped cream, butter-based sauces and even butter itself. But mastering the art of emulsions isn't easy.
The keys to any emulsion are timing and temperature. Let's take for example beurre blanc. To make this traditional French butter sauce, you first add cream to your base of shallot, reduced white wine, and whatever aromatics you choose (in our case black peppercorns).
Already, you technically have an emulsion since cream is really just fat dispersed in water, but to achieve the rich mouthfeel of a French sauce, you need to emulsify further and this is where temperature and timing are of the essence. The trick is to keep the butter cold, the pan warm (but not too hot!), and the whisk moving quickly.
By gradually adding chilled butter to the mixture while whisking, you help regulate the temperature of the sauce. This allows the butter’s water and fat globules to separate slowly as it melts so that, through the agitation of the whisk, you break the fat into even smaller pieces to emulsify these two incompatible liquids. You’ll know the sauce is ready when it has thickened, and it comes back together quickly when you run a spoon through it. Emulsions are best served immediately because too much heat or re-heating can break the delicate structure holding them together.
With the Hestan Cue, we've tested and tuned our beurre blanc recipe so the time and temperature are just right. All you have to worry about is the whisking! So now that you've got the science down, ready to test your skills? Check out one of our favorite pairings for this decadent sauce: Pan Seared Scallops with Beurre Blanc!