STiR coffee and tea magazine

Volume 4, Number 4

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32 STiR tea & coffee industry international / Issue 4, 2015 (August/September) By Jenny Neill Agtron E20CP near-infrared spectrophotometer Sinar BeanPro 6070 measures moisture/density Photovolt 580-PC coffee classification system oast degree, under development, and over development – listen to coffee roasters talk shop and sooner or later you will hear these terms. Used alone or with other descriptors, each acts as profes- sional shorthand for flavor profile. Some prefer the more romantic terms as- sociated with cupping to assess quality. Even those, however, often choose to bring a more scientific analysis to bear when a signature product is not coming out of the roaster with the expected aromas, or with too much or too little acidity on the tongue once brewed. Refractometers, tools available since the 19th century, give clues to a liq- uid's sugar or soluble content. Just as roasters talk of over development, baris- tas talk of over extraction and using a Brix meter, a type of refractometer, can help assess extraction levels. Its popularity as a tool with baristas has attracted the attention of some roasters too. John Johnson, coffee specialist at Rising Star Coffee Roasters in Cleveland, Ohio, considers measurements from his VST LAB Coffee III Refractometer a valuable adjunct to cupping coffees regularly. The Rising Star team collects data on such variables as air and bean temperature, and rate of temperature rise during roast cycles through a Roaster Dynamics control system as a way to standardize development of flavor profiles for products. Adding in readings from the VST Refractometer "…helps us interpret that data," said Johnson. One example Johnson gives is that "the amount of energy we have to get into the bean isn't the same every season." The ambient air in the roasting plant is much cooler in January when outside it could be 0°F with no humid- ity. Compare that to a day in July when daytime temperatures exceed 80°F with relative humidity well above 60%. Jason Webb, director of Sinar Technology, suggested one of the products his company sells might also be useful to a roaster like Johnson. The Sinar BeanPro 6070 measures both moisture and the density of the whole bean. Both variables can shift how a roaster chooses to handle the roasting process and tracking moisture levels before and after will have increasing importance as the international definitions of quality shift. That a cup of coffee should give pleasure is a given and implementing a quality control program is essential for any roaster who wants to ensure repeated success with that. However, the legal definition of quality is chang- ing too as new or revised food safety rules progress from proposal to imple- mented requirement. How Precise Measurements of Light Enhance Quality Control Soon, the brown brew must also prove to be free of certain chemicals or other defects. This is where the advances beyond the 19th century era hand-held refractometer become more important to understand. The importance of standards The science of measuring and interpreting energy and light advanced quickly with the first interna- tional standards being agreed to in the early 20th century. These developments were crucial to the development of many fields: photography, graphic design, and food science among them. Why are color standards so important to un- derstand when shopping for quality control equip- ment for roasted coffee? They have become an es- sential part of the language of food science. Ann Hildreth, director of business develop- ment at Photovolt Instruments, said, international standards are important because "Measurements which are made need traceability to standards. The major international standards centers are in United Kingdom, Germany, United States, and Japan. These centers also have cross references between them. By having instruments which are traceable to these standards the measurements are accurate and correct around the world." Furthermore, more than one even narrower such standard exists for interpreting the data pro- duced when taking measurements with instru- ments designed for coffee. R Photo by Dan Bolton

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