The biggest difference is the texture. Restaurants margs have a smooth, thick, almost creamy texture. The ones I was making were more icy and granular, like a boozy snow-cone. I looked at buying a restaurant-style continuous mixer, but they're pretty expensive and I'd have to do a lot of drinking to justify it. Which isn't that much of a burden, but I don't want to become an alcoholic solely to amortize capital costs.
Somewhere along the way I read that some of the commercial mixers took all liquid ingredients, rather than a bunch of ice and booze. So I figured I'd give that a try. And it turns out that's the secret! You just replace the ice with liquid water, freeze the whole thing, and you get a much better texture. The problem is that if you mix it all up at once, it'll separate in the freezer. Then you end up with a lake of concentrated booze and sugar, topped by a glacier that'll take 15 minutes and a pickaxe to pierce. So it's better to add some water and blend, freeze that, then add some more water and blend again. It ends up taking a day or two to make a pitcher of margs, but that's probably for the best anyway. Along the way I also tried out a Bacardi margarita mixer that I like a lot better than limeade, which was also an improvement.
Eventually I sobered up a bit and became curious about why the texture was different. I could probably ask a food scientist or a physicist, but I'm lazy and the internet is right there. So I did some Googling, read some stuff about formation of ice crystals, and made some completely unfounded conjectures which I will now present as "knowledge." Basically I think when you start with ice cubes you have relatively large crystals, which get chopped into smaller ones in the blender but are never very small. But when you start from a mixture of water, sugar, alcohol, salt, etc the water freezes into much smaller crystals because of the freeze concentration. Basically as the water freezes into pure ice, the remaining liquid has a higher concentration of solutes, which makes it even harder for the remaining water to freeze thus preventing larger crystals from forming. I think. Anyway, here are some really fascinating pages on the formation of crystals in ice cream, which seems like mostly the same thing.
So there you have it - better drinking through physics. My next task is trying to make better frozen margs from scratch. I've had one promising batch, but I haven't worked out a repeatable recipe yet. It looks like it'll be roughly the same as above, but replacing the premix with 3/4 cup of lime juice and 3/2 cup of simple syrup, give or take. I might also try extra-strength simple syrup. Anyway, I'll let you know when I figure it out, if I'm still capable of typing by then.
Update - here's my best stab at a good recipe before I call it quits for the season.
- 8 oz tequila
- 4 oz triple sec
- 6 oz lime juice
- 10 oz simple syrup
- 20 oz water
Mix together everything but the water in a large blender. If you're not sure of the recipe, you may want to go easy on the lime juice and simple syrup - you can always add more later. Add 8oz of water. Freeze for 6-8 hours, stirring a couple times if possible. Take out of freezer. Taste and adjust lime/syrup ratio if needed. Add remaining water and blend. Refreeze, stirring a couple more times if possible. Blend again before serving.
All amounts are easily modified if you like it stronger/weaker, more/less limey, more/less sweet. But if you add too much water it will be more difficult to blend after freezing.
Use a long serving spoon to mix while blending. Before serving it should be liquid enough to maintain a smooth flow in the blender without assistance.