An experiment with sous vide spirits

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As a cocktail blogger I’m used to getting samples of spirits in the mail. I’m not used to them arriving in bags like those pictured above. Is that Aviation gin’s sexy new packaging? No, but it is Aviation gin, cleverly altered by my friend David Barzelay for a tasting experiment.

David is very interested in the science of cooking and has lately been getting into cocktails as well. One of his recent acquisitions is an immersion circulator used for sous vide preparations. (How he got his circulator working is a story in itself, worth reading here.) In brief, sous vide cooking works by sealing food in an airtight plastic bag and immersing it in a temperature-controlled hot water bath. Because the heat source is the same temperature as the target temperature of the food, the bag can be immersed for hours and the food will cook evenly all the way through. This has numerous uses in the kitchen, but what about behind the bar?

David’s idea was to use the sous vide technique to increase the strength of an infusion. Since heat aids in the extraction of flavor, sous vide could allow one to achieve the same results as room-temperature infusions in a shorter period of time or with smaller amounts of ingredients. The sealed environment would minimize effects on the spirit, allowing any vapor to recondense into the liquid. David sent me four samples of Aviation gin to test whether 1) the spirit’s aroma, flavor, or mouthfeel would be altered and 2) whether a sous vide infusion would be stronger than an unheated one. The following four samples arrived in separately sealed bags:

1. 50g Aviation gin, untreated
2. 50g Aviation gin, heated for 60 minutes at 60C/140F
3. 50g Aviation gin, bagged with 10g juniper berries
4. 100g Aviation gin, bagged with 20g juniper berries, heated for 60 minutes at 60C/140F

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David suggested tasting these side-by-side with a few other gin lovers. Luckily Aviation is distilled right here in Portland by House Spirits, so I was able to taste these with the distiller himself. Our tasting panel consisted of me, Matt Mount and Lee Medoff from House Spirits, local bartender Elizabeth Markham, and visiting cocktail enthusiast Courtney Knapp, who also took the photos.

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I’ll discuss the infusions first. David says that when he mailed them to me the heated infusion had become dark brown from the juniper berries and the untreated infusion was still clear. By the time they arrived in Portland a few days later they were both brown and another several weeks would pass before I got around to the tasting them. Ideally we would have conducted the tasting soon after the infusions were made, but that wasn’t possible this time.

Nonetheless, the juniper flavor was still much stronger in the sous vide infusion. In both infusions the juniper overpowered other flavors, but in the heated sample it was even more pronounced and longer lasting; one taster said it felt as if the oils lingered longer on the tongue.

Was this the result of a stronger infusion? Probably in part, but there was an unexpected result from the sample that was heated without any added juniper berries: It tasted more like juniper too!

The first thing we noticed in the heated sample was that it had some visible solids or oils on the surface. It also tasted much more intense than untreated Aviation gin; “resinous” and “piney” were two descriptors we came up with. The sous vide process definitely had an effect on the spirit.

We’re not sure why the result came out this way. The temperature was below the boiling points of methanol and ethanol. Matt suggested that the process might have volatilized some of the juniper present in the gin, which he says is one of the first botanicals to express itself in the distilling process. This would perhaps explain why there was apparently oil on the surface of the sample and why junipery, piney flavors were enhanced to the detriment of floral, citrus, and spice notes.

Additional experiments could help shed light on how the sous vide process affects spirits. One possibility would be to repeat the infusion experiment with cardamom or coriander, two ingredients that Matt says express themselves at the end of distillation, or with an ingredient not found in the gin at all. Another would be to use vodka, which with its neutral flavor and purity would present fewer complications. Shorter heating times could also be tried; for example, DC bartender Justin Guthrie does a sous vide infusion of Jim Beam bourbon and Madras curry that takes just a few minutes and Tony Conigliaro does a 20 minute apple and gin infusion. They both use lower temperatures as well. Finally, Elizabeth suggested the technique could be useful in speeding up the making of bitters, which could be a great application.

Hopefully David will check in with his own thoughts and I’d like to hear from anyone else who’s tried this. I think the technique could have a lot of untapped potential.

Comments

  1. bradley dawson says:

    I’m wondering if volatile compounds have different evaporation temperatures as metals do? Not a chemist, but from infusion experience, it seems a sound theory. It would explain quite a bit.

  2. Barzelay says:

    I must admit, it was my hope that the cooked spirit (without the added juniper) would be unaltered from the heat. However, I did fear that heating would cause one of many problems. Some of the dissolved oils and particles might fall out of solution when the temperature changes drastically. Certain compounds may be soluble only at certain temperatures. And certain compounds in the spirit may react with one another only above a certain temperature, and the reactions may produce new, dissoluble particles (this happens with iced tea, for instance–iced tea becomes cloudy because caffeine reacts with some of the other chemicals in the tea, producing salts that are soluble only in hot water).

    It’s interesting comparing the flavor effects of cooking sous vide to the actual distillation. Distillation is something at which I have absolutely no experience. But, for instance, when making stock, experience tells me that even though you keep the stock simmering at 100C the entire time you’re making it, most of the “flavors” come out of the bones and meat very quickly, compared to the slow breakdown and leeching out of the gelatin that gives the stock “body.” The oiliness you describe sounds suspiciously similar.

    Did you also tried the untreated sample against freshly poured Aviation gin? I’m wondering whether the vacuum-sealing, the trip, or the time in a closed environment may have had an effect.

    We can try this again some time, and I can use a lower temperature and less time, and maybe coriander, which is a lot milder than juniper berries. Send me one of those sample bottles some time, and I’ll send it back bagged and cooked.

  3. Jacob Grier says:

    @Barzelay: Yes, we tried the control sample too, and it tasted like ordinary Aviation gin. I’d definitely be up for trying this again sometime with some different variable.

  4. john thompson says:

    Tony Conigliaro has been using this process for years check out his work at Shochu lounge from 2003.

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  1. [...] didn’t (once again) mention what a great blog Jacob is writing over there. His recent bit on sous vide spirits was fascinating and well done and his tiny rant on the Whole Foods boycott seems exactly right to [...]

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