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
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.
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.