The consumer of beer drinks as much with the eyes as with the mouth. Certainly beer drinking can be as visually pleasing as it is thirst quenching. The quality attributes of beer that are perceived by the eye can certainly influence our perception of flavor, as demonstrated by a simple experiment. Try adding a few drops of a flavorless dye (the type you may use in your kitchen) to a lager such that the color darkens to that more typical of ale. People presented with this beer will judge its flavor to be closer to that of an ale than a lager, whereas if they are blindfolded they certainly won’t be able to tell apart the taste of the beer before and after the dye has been added.
Color is just one visual quality parameter of beer. Most people (other than those smitten with hefeweissens) prefer their beers to be sparkling bright, with no suggestion of cloud or haze. However, there is variation in the extent to which drinkers like a head of foam on beer. In some countriesa copious delivery of foam on dispense is essential: for instance, it is traditionalin countries such as Belgium for as much as half the contents of the glass to consist of froth. In the United Kingdom, there are distinct regional differences: in some places, for example London and the Southeast, foamseems frequently to be regarded as an inconvenience. By contrast, a stablehead, perhaps 2 inches deep, is generally required in the north of England.But unlike, say, the Belgian, many an Englishman appears to want foam anda full measure of beer. Matters reached a head (one might say) when the status of beer foam was challenged in the courts of law. Those insisting on a full pint of liquid challenged landlords who dutifully dispensed the beer with a head. The most recent High Court judgment was that a reasonably sized head should be regarded as an integral feature of the beer, but that the customer is within his rights to insist on a full measure of liquid beer. Such concerns are only relevant, of course, for draft beer. For beer in cans and bottles, the volume is fixed. Whether a head is generated or not is more often in the hands of the customer than the bartender. Indeed, that’s if the beer gets poured at all. Some prefer their beer directly out of the bottle or can, in which case foam (and color and clarity, for that matter) assume a more academic dimension.
In just the same way that color influences the perception of the flavor of a beer, so too does the head seem to affect a drinker’s judgment (fig. 3.1). Again there is undoubtedly a psychological component at work here. It is, however, likely that the presence of a foam does have a direct bearing on the release of flavor components from the beer: in other words, a beer will smell differently when it does as opposed to when it does not display a head of foam. Not only that, but there are substances present in beer that have a tendency to move into surfaces such as the bubble walls in foam and are therefore called “surface-active compounds.” These include the bitter compounds, and so the foam has proportionately more bitterness than has the rest of the beer.
You can see, then, that long before a drinker raises the glass to her lips, she will have already made some telling judgments on its quality, drawn from visual stimuli alone: the quality of the can or bottle, the “font,” if the beer is on draft dispense, the appearance of the foam, the color, and whetherthe beer is cloudy. And all this is quite apart from the effect of other stimuli associated with the place in which the beer is being drunk: the lighting, the background music, the attractiveness of the bar layout, the foodstuffs being consumed alongside the beer, and even the company being kept. Beer flavor is important, of course, but even the most delicious of beers won’t be enjoyed if all the other elements of the drinking experience are flat.