Here's a picture of a Jack Rose I made last night. It tasted great, but I think the white foam is ugly. I want it to be clear and jewel-like with no foam.
All my shaken drinks have this foam. I have not observed similar foam on drinks I order in bars. What are techniques for avoiding or getting rid of the foam?
Maybe I could scoop it off with a spoon, but I think I would lose too much of the drink that way, and anyway that's not what the bartender does, so I think there must be a better way.
[ The recipe I am using is: four parts homemade applejack; two parts lime juice, one part homemade grenadine, shaken with ice cubes in a metal shaker, then poured into a chilled glass. The shaker has a perforated top, but I am not otherwise using a strainer. ]
Best Answer
Foam in shaken cocktails is often actually considered a desirable quality. This is the reason why you'll sometimes see egg white included in recipes like the whiskey sour - the proteins in the egg white help to maintain a long-lasting froth on top of the cocktail, which many drinkers find appealing. It adds a slightly different mouthfeel too and can make a nice change in some cocktails.
So, while I encourage you not to discount the foam completely, understanding what helps produce foam can also help you to avoid it. Scientifically-minded bartenders have conducted experiments on foam and how to produce it which we can learn from.
Basically, the foam is a collection of tiny air bubbles dispersed in the liquid, which is mediated by emulsifiers and proteins in the citrus juice. This is commonly lemon juice or lime juice (both of which do actually contain a small amount of protein) and could be either depending on the Jack Rose recipe that you're using. The more viscous the liquid mixture, the more stable the bubbles will be. Forming the foam in the first place takes a fair amount of force, which you provide with turbulence when you shake the drink with ice.
This suggests a few possible approaches: change how much turbulence you produce, change the viscosity, or try to eliminate the proteins.
Changing your method
Let's start with the approach that's easiest and most practical for the home bartender. This involves building the drink differently to generate less turbulence.
Change the viscosity
This gets a little more difficult, because the main element affecting viscosity in cocktails is sugar, which also balances the flavor of the drink. If you simply make the drink less sweet, you might wind up with less foam, but it'll also taste different. Still, there are a couple things you can try for the Jack Rose in particular.
Reduce the protein
The idea here is to eliminate some of the proteins from the citrus juice that mediate the formation of foam. That sounds promising, but it's also fairly advanced and perhaps too much work to make yourself a drink or two. Still, experimentation can be fun and worth exploring.
Note that for the Jack Rose in particular, pomegranate juice also contains proteins; if you're making your own grenadine as suggested above, you can do this with all the juices that you use.
It probably goes without saying, but you can combine as many of these ideas as you want. Start with changing up your method and move down the list if you're still not satisfied with the results.