Feeling slightly flummoxed that a master sommelier doesn’t rely on palate cleansers, we turned to the commercial food industry to seek out real-world palate-cleansing practitioners. Palate cleansers play a central role in sensory analysis studies conducted by major food companies. (According to the book Guidelines for Sensory Analysis in Food Product Development and Quality Control, sensory analysis is defined as “the identification, scientific measurement, analysis, and interpretation of the properties (attributes) of a product as they are perceived through the five senses of sight, smell, taste, touch, and hearing.”) To learn more about the use of palate cleansers in the food industry, we asked Dr. Sarah Kemp, a food science consultant and former global head of sensory and consumer guidance at Cadbury Schweppes, her opinion on the matter. Kemp has helped design and lead many studies, such as one focused on the sensory characteristics of tomato sauces available in the United Kingdom market and exactly what qualities U.K. consumers desire. Kemp stressed that using a palate cleanser is critical to the success of these studies. “The aim of palate cleansers is to minimize carryover effects and adaptation from the previous sample.” In other words, palate cleansers are used “to reset the sensory system back to its base state.” The theory goes that by wiping the subject’s palate clean of the taste of the previous sample, palate cleansers prevent the tastes of samples from contaminating each other. The ideal in a sensory study is that if a subject were to taste the same sample at multiple points in a sensory test, that person would rate the sample identically each and every time.
To obtain reliable sensory data, food scientists seek out the best palate cleansers. And to determine the best palate cleansers, stand-alone studies have measured the efficacy of a wide variety of possible candidates. The results? Bland is best. The blandest of the bland, in fact. “Water at room temperature,” said Kemp. And not just any water. Water that is “as bland as possible, for example, distilled water or bottled water with minimal taste.”
In a 2009 paper from the journal Chemosensory Perception, researchers tested a variety of palate cleansers, including Table Water crackers, spring water, pectin solutions, whole milk, and warm water, in combination with a range of foods that each fell into different categories of taste sensations (from sweet, bitter, and fatty to astringent (the dry, grippy feeling in the mouth after tasting things like unripe fruit, black tea, and wine that’s high in tannins), hot and spicy, and minty and cooling). The only palate cleanser that was effective across all foods types was the cracker. Indeed, a literature search of recent food sensory studies published in peer-reviewed journals reveals that the most common palate cleanser in food sensory studies is a sip of water followed by a bite of unsalted crackers, such as unsalted saltines, which sound like an oxymoron but are very, very real. Unsalted saltines have a very small amount of salt in the cracker itself, but lack salt granules on the top.