by Paul Adams
Welcome back to Cooking Issues. It’s been a while. The blog here got a little bit snowed under with male-enhancement spam while the staff’s attention was on other things, but I volunteered to come shovel it out–I spend my days at Popular Science–and now posting shall resume!
What’s Dave been busy with? A year ago, he opened a cocktail bar, called Booker and Dax, and that’s been going pretty well. Stop by if you’re in the area! Now I’ve been burdened with the terrible, arduous job of drinking the drinks that the bar serves and writing them up.
Let’s start with the Bangkok Daiquiri, which is delicious, simple, ingenious, and very pretty to look at. Ingredients: Thai basil, lime juice, white rum. Technique: cryomuddling.
Muddle up basil or many another leafy green herb and it immediately starts to a) turn drab in color and b) acquire that unfortunate swampy overcooked-spinach off-flavor. Both of these are caused by enzymatic action: busting up the cell walls of the leaves releases polyphenol oxidase (PPO), an enzyme that causes the tasty phenolic compounds in the basil to oxidize, making the basil sad.
There are a few clever strategies for getting fresh herb flavor into a drink without the nasty oxidation products. You can rotovap; a colorless but tasty basil distillate; or quick-infuse with nitrous. Or you can just be real gentle with your herbs: Harold McGee has pointed out that the aromatic compounds in basil and mint mostly reside in hairs on the undersides of the leaves, so smacking or rubbing or two leaves together without crushing them releases good flavor and minimum PPO.
For service at the bar, a wholly different technique is used. Meet cryomuddling, a.k.a. nitromuddling.
Drop your basil leaves into your muddling glass and then immediately pour in a dose of liquid nitrogen and swirl it around to freeze the leaves. THEN you muddle them to your heart’s content, because no browning reaction is going to happen while the enzyme is inactivated by the intense cold. The leaves are brittle and the muddling has the feeling of walking crunchily through dry, cold snow. It’s easy to muddle them down into a fine powder. Fine powder equals lots of surface area equals quick flavor release.
Pour the rum over the basil powder (having drained off any remaining liquid nitrogen) and it comes alive with bright green. At this point the ethanol deactivates the polyphenol oxidase. (Dave suspects that the enzyme may be permanently denatured, but further testing is needed.) A great percentage of the plant’s PPO has been liberated from its cells, so enzyme action is no longer a concern as the drink comes up to non-cryonic temperatures. It stays bright green and fresh-tasting.
If the basil is muddled into a less fine powder, the drink does get a little browner, likely because there’s still PPO inside the leaves that the ethanol doesn’t get a chance to work on before oxygen hits it.
Double-strain the basil-y rum, shake with lime juice and simple syrup, serve in a chilled coupe.
If you don’t have liquid nitrogen at your bar or home (probably your nitro delivery guy is just late) you can make a Bangkok Daiquiri in your blender that Dave says is “90 percent as good.”
For two servings:
15-20 leaves of Thai basil
5 ounces white rum
“a fat 1.5” ounces lime juice
“a skinny 1.5” ounces 1:1 simple syrup
Blend the basil with the rum into a slurry–don’t overdo it–then immediately add the lime, then the simple. Strain before shaking.
Booker and Dax puts about a centigram of salt in every drink too: a couple drops of 1:5 saline solution. Dave believes it rounds out and brightens the flavor. We can test this notion in another post.