So I’m watching a yewtoob cooking vid and the chef is making langosteen braised in de-natured vodka. But it got me wondering…vodka is essentially tasteless in itself, what the hell do you get when you burn the alcohol out??
A cool show. Isn’t that the real reason for something like that?
I love me some flambé. When my gf makes oxtail soup she has me do the flambé part. Honestly I think it’s mostly for show. Simmering for a bit would have the same results.
Also, despite what many think, not all of the alcohol burns off. So you get a neat show, and a bit of a buzz.
Yeah, I think mostly when food is set on fire it’s purely for show. Years ago, pre-children, when I used to have fun, we’d sometimes go to restaurants in Detroit’s Greektown area, where the thing was to order the Saganaki appetizer, ‘flaming cheese’. The waiter sets it on fire at the table, yells out ‘OPA!’ and then puts the fire out with a lemon squeeze. At least the lemon is supposed to put the fire out-- I think this guy used a wee bit too much of whatever alcohol he poured on there 
If there is a practical reason for why it’s ever done, I don’t know the specifics of the recipe to which the OP refers, but I know vodka, although tasteless in itself, is sometimes used as a ‘solvent’ in recipes. There’s a tomato-vodka-cream pasta sauce in which the alcohol in the vodka is supposed to unlock flavor compounds in the tomatoes. In the case of the sauce the alcohol is mostly evaporated in the cooking process, but in the OP’s recipe maybe the cooking time is not enough to cook out the alcohol sufficiently after it’s done its thing, so the fire is just to burn off the excess alcohol…?
A few thoughts from a voracious consumer of vodka … 
Vodka absolutely is NOT “tasteless”. It’s just that the differences in flavours among different brands tend to be more subtle than with most other liquors. Also, the alcohol packs a wallop – you can certainly tell the difference between a glass of vodka and a glass of spring water!
According to the “tasteless” theory, using vodka in cooking and burning off or simmering off the alcohol is equivalent to just adding water to the dish. This is clearly not the case, and I submit that part of the reason is the residual flavours in what remains after some of the alcohol burns off, and also the fact that not all the alcohol is lost (as I just noticed @Chronos pointed out).
Another point is brought to mind by a wonderful flambé dessert that was served at a restaurant I used to go to. I loved it so much that I asked them for the recipe, which they cheerfully gave me. I put it in a cookbook which is packed away somewhere so I don’t have immediate access to it, but it was basically a grown-up banana split: a split banana, vanilla ice cream, a bunch of other stuff that I don’t recall, and then about three different liqueures which were set on fire. Yes, a lot of it was for show, but the flames also singed the banana, so the showy flambé was also an integral part of the preparation. I suspect that in the OP’s example, the flambé was an essential part of preparing the langosteen.
Incidentally, while I know that langosteen is considered a delicacy, I’d never eat the damn things myself. Sea-dwelling giant insects is what they are, if you ask me!
And way less burns off than people assume.
Flambéing leaves 75% of the alcohol in the food.
Baked/simmered dishes with alcohol stirred in:
-
15 minutes cooking time / 40% -
30 minutes / 35% -
1 hour / 25% -
1.5 hours / 20% -
2 hours / 10% -
2.5 hours / 5%
Relevant chart on page 12:
You’re describing
Which exists in as many variations as there are cooks. I used to make that at home for a big flourish at the end of a fancy meal.
At least in part, it gives the cook the ability to burn it off in a controlled manner instead of ending up with a cloud of alcohol vapor hanging out over a gas burner.
It’s a variant of that, and thanks for the reference, but the liqueurs were quite different. As I said, the recipe is packed away somewhere in an old cookbook, but I don’t think rum was involved, but I’m pretty sure that Grand Marnier was. As you say, it exists in many variations, and obviously the restaurant just invented a variation of Bananas Foster.
ETA: I had not known about Bananas Foster before, thank you. I always thought that the restaurant had developed this dish from scratch!
Looks like it doesn’t actually make much difference to the flavor, unless you add too much, in which case it imparts an unpleasant bitterness.
Maybe he just didn’t do it right. Soaking vanilla beans in vodka and then adding some of the vanilla-infused vodka to my cookies certainly makes a noticable difference.
Vanillin is definitely alcohol-soluble (but not water-soluble). It’s conceivable that there’s likewise some flavor component of tomatoes (or other herbs or whatever) that’s soluble in alcohol but not water, and that it’s a significant contributor to the overall flavor of the dish. But it’s also conceivable that there isn’t.
A friend insisted all vodkas taste the same. I set up a taste test at a party. Grey Goose, Belvedere, and Nikolai. I took a sip of each of three glasses and immediately identified them correctly. I love all three, each for their own reasons. Nikolai is dirt cheap, so I usually have it at home.
Is this correct? De-natured?
Sure, but you have to be under somewhat controlled conditions to tell a good rye vodka from a good wheat vodka. If they’re easily distinguished based on raw materials, I’d argue the distiller’s doing a poor job and giving you something more akin to white dog than vodka.
In my experience, the main differentiators on vodka have to do with the water used to dilute it, and the “smoothness” of the vodka itself, which is more of an indication of the distillers’ care and skill than the raw materials that were used.
Culinarily speaking, the relative tastelessness of vodka is the entire point- vodka sauce with a quarter-cup of rum would be godawful, as would a quarter-cup of brandy or whiskey. But vodka doesn’t really interfere, and has putative solvent effects on tomato compounds.
Now why would someone flame the vodka? That’s totally got to be for show, which is basically the point of flambeing any booze. Otherwise, you’d either mist a little over the top, or you’d just cook it in. Like @Chronos and @DCnDC point out, not very much alcohol actually burns off in such a short time as a flambe. So a minor alcohol flavor and a lot of show is the point of using vodka. Sometimes brandy is used (saganaki, steak au poivre, etc.), and in those, I think the brandy flavor is part of the point.
I’ve made that tomato-vodka-cream sauce a couple times and I agree, I haven’t noticed any amazing flavor improvements over a tomato-based sauce without added vodka. My point was just that the only reason I can see to add vodka to a dish is so that the alcohol can, theoretically at least, cause a chemical change that improves the overall flavor.
My describing vodka as ‘flavorless’ in that sense was not in reference to its flavor of lack thereof as a beverage, but that it’s a ‘clean’ type of alcohol to add to a dish when you just want the alcohol in the vodka to do its thing. You don’t add vodka to a dish to give it a distinct ‘vodka’ flavor in the same way you do when you add, say, Cognac or wine to a dish. So in my view, the only reasons to add vodka to a dish are to possibly cause a chemical-based flavor improvement from the alcohol alone, or to set the dish on fire for a cool display (or both).
Well, it is a great show. But you also get a little burning of other ingredients, sometimes. Which can affect their flavor.