The Science of Taste: Sweet

One of my favourite seminars that I've been to was the "Science of Taste" by Darcy O'Neil at the Art of the Cocktail festival in Victoria last year. Darcy is a man after my own heart because he not only writes about spirits, bitters, and cocktails, he also happens to be a working chemist and ties science into drinking (I myself went to university for chemistry). Check out his website at www.artofdrink.com
He also wrote the book "Fix The Pumps" on the history of the soda fountain, something I mentioned in Russell Davis' Averna soda cocktail from last month's Amaro April.

His presentation was on taste from a scientific perspective, and how this knowledge can be applied to mixology and bartending. He was kind enough to send me the slide show that he used and I'm going to paraphrase certain parts of it here (to see the full show, you'll just have to catch him wherever he takes it next). I found this information not only extremely interesting, but also really helpful in balancing my drinks at home. I'm going to split this into several posts - a number focusing on the types of taste as perceived by your tongue and how they can interact with each other in terms of designing and balancing a drink, and the last focusing on other factors that can affect taste, including even mood and body-type, and how you can use this information as a bartender. It's also necessary to preface this with the fact that everyone has different taste. This is true biologically and psychologically, so everything below is a general rule.

Most of us are aware of the basic taste groups - sweet, sour, salty, bitter, and savory. There are also scientifically proven, but as of yet unrecognized groups including metallic, spiciness, and coolness (the last of which is a nerve response and not a flavour response). Taste is very much affected by aroma, viscosity, temperature, mood, genetics, and social aspects of the tasting itself, but these are all things I will summarize later on. To start, we will look at sweetness.

Sweet

Sugar is a chemical fuel for our bodies, and we therefore biologically seek out sweet flavours (hence the increasing amounts of sugar in manufactured and fast foods over the last 50 years or more) - some more than others (see: dude with big gulp full of Coke at the 7-11 or anything on the cocktail list at a chain restaurant). Sweet is the only taste that decreases the perception of other flavours, explaining why sugar continually gets added to both food and drink to hide other tastes.

Now here's where the chemistry comes in:
Increasing sweetness will
- Reduce saltiness
- Reduce acidity (sourness)
- Reduce bitterness.

There are other ways to balance a drink by making it seem sweeter than just adding sugar, such as:
- Increasing the viscosity (via egg white, for example)
- Reducing the bitterness
- Reducing the acidity/sourness
- Reducing the alcohol-level (proof).

So if your drink is a little too sour or bitter, you could add egg white, or increase the dilution to balance what you have.
Secondarily, there are some flavours that increase the perception of sweetness:
- stawberry
- lychee
- caramel
- vanilla
- banana

and some that decrease the perception of sweetness:
- angelica
- floral
- cedar
- juniper.

If your drink is going to be too sweet, using gin as a base or adding a little rose water could balance it, and if your drink isn't sweet enough, you could find creative ways to add other flavours without adding straight sugar (for example, Licor 43 has a strong vanilla flavour, and St. Germain has some lychee similarities).

The lesson here is that sugar is not always necessary, and too much can ruin drinks (and started ruining them in general in the 1970's and still continues today). There are other solutions to balancing a cocktail than just making it more sweet. I should point out that all of the above is related to the PERCEIVED taste of the mixture. So adding sugar does not reduce acidity/sourness, or change the amount of citrus juice in your drink, but it will make your tongue think that this is the case. This is the whole science behind adding too much sugar to drinks in the first place - people want to drink a lot of alcohol without tasting it, and the easiest, quickest, dumbest way to do that is to add tons of sugar. The alcohol level doesn't change, but your tongue thinks it does.

Also check out these posts on
Personality & genetics
other non-tongue factors
savory & bitter
salty & sour


[[ Photo by Dario Pignatelli/Bloomberg from the Financial Post ]]