Some Like It Too Hot? Rethinking Coffee Serving Practices
Creators: name: Lachenmeier, Dirk W
name: Schwarz, Steffen
Publisher: name: Zenodo
Year: 2018
Subjects: coffee
temperature
cancer

description: When questioning professionals or consumers about <strong>influences on coffee quality</strong>, <em>factors such as type, variety and origin, processing, sorting, gentle roasting, fresh grinding or the type of preparation are usually named</em>. Very rarely, however, is the <strong>temperature</strong> is brought into play. According to popular opinion, the best way to think with coffee is “<strong>the hotter the better</strong>“. This belief needs to be tackled in two ways.

On the one hand, <strong>brewing and drinking temperatures have a considerable influence on the sensory quality of the beverage.</strong> Brewing should by no means take place at temperatures <strong>higher than 92 °C</strong>,<em> since above this temperature undesirable bitter and astringent substances clearly dominate the flavour profile.</em> On the other hand, <strong>below 70 °C </strong>brewing temperature,<em> the cup is dramatically flat and watery, as fat-soluble substances and aromas are significantly reduced in particular.</em> <strong>The optimum brewing temperature thus usually falls into the range of 85-92 °C, also dependent on other parameters such as machine type, pressure, and percolation time.</strong>

According to current own research results of more than 300 temperature measurements in gastronomy in southern Germany, <strong>the coffee-serving temperature is around 70-80 °C (average 75 °C)</strong>. This temperature is considered to be very high and significant cooling is required to achieve a satisfying taste experience. <em>In an orienting cup tasting, we tasted an identically brewed coffee at 62 °C, 54 °C and 45 °C. </em>At the highest temperature the taste was not even noticeable (at this temperature range, the feedback of pain receptors appears to completely overlay the one of the taste buds). <strong>At 54 °C, the coffee was much more acidic and fruity</strong>. <strong>The best flavour profile was described at the lowest temperature</strong>, <em>with pronounced acidity and sweetness and a pronounced body, a dramatic difference from the highest temperature</em>.

The reason for this observation is the fact that <strong>in a cupping at 45 ° C, the coffee in the oral cavity will be around the same as our body temperature.</strong> <strong>Above fever temperatures (42 °C), pain reactions and irritation of the oral mucosa due to protein denaturation cannot be ruled out.</strong> For the same reason, i.e. in order to avoid protein denaturation, the temperature for cappuccino preparation should also be mafr lower than what is common practice. In particular,<strong> the creaminess and elasticity of a perfect milk foam cannot be achieved at the usual temperatures in gastronomy, which are much too high.</strong> <em>The result is an empty “bath foam”, which lacks any creaminess.</em>

These considerations already show that <strong>too high drinking temperatures also have an effect on the human body.</strong> In fact, studies from countries where drinks are consumed very hot (such as tea in Iran or mate in South America) have shown that this drinking behaviour significantly <strong>increases the risk of developing esophageal cancer</strong>. The International Agency for Research on Cancer (IARC) of the World Health Organization (WHO) has classified <strong>“very hot”</strong> beverages as <strong>“probably carcinogenic to humans”</strong> on the basis of epidemiological investigations worldwide. As threshold for <strong>“very hot”</strong>, <strong>the IARC indicates a temperature of 65 °C.</strong> Thus,<em> the above-mentioned serving temperature of coffee in Germany (75 °C) is above this threshold for probable carcinogenicity.</em>

For both reasons (<strong>improved taste quality, exclusion of a cancer risk</strong>) coffee should therefore be consumed at <strong>lower temperatures</strong> than what is currently the case. For this purpose, a paradigm shift in gastronomy and consumers must be made towards <strong>“the hotter the worse”</strong>. As a first measure, the machine output temperature could be limited at <strong>below 80 °C</strong>. <strong>The serving temperature should be below 70 °C so that the consumption temperature is usually below the IARC threshold of 65 °C</strong>.

Then the barista can also present his coffee expertise with a special taste experience and also serve a perfect cappuccino, which is remembered not only for thermal off-flavours.