- Coffee filter
Paper filters remove oily components called diterpenes; these organic compounds, present in unfiltered coffee, appear to increase the risk of coronary heart disease. Metal or plastic mesh filters do not remove these components.
On July 8, 1908, the first paper coffee filter was created by German housewife named Melitta Bentz. She wanted to remove the bitter taste caused by boiling loose grounds or using the typical method of linen to brew coffee.
Coffee filters of paper are made from about 100 g/m2 crêpe paper. The crêping allows the coffee to flow freely between the filter and the filtration funnel. The raw materials (pulp) for the filter paper are coarse long fiber, often from fast growing trees. Both bleached and unbleached qualities are made.
For a filter to be compatible with a coffee maker, the filter needs to be a specific shape and size. Common in the United States are cone-shaped filters #2, #4, and #6, as well as basket-shaped filters in an 8-12 cup size.
Other important parameters are strength, compatibility, efficiency and capacity.
If a coffee filter doesn't possess enough strength, it will tear or rupture, and many of the coffee grains will collect in the coffee pot. Compatibility describes a filter medium's resistance to degradation by heat and chemical attack; a filter that is not compatible with the liquid passing through it is likely to break down, losing strength (structural failure). Efficiency is the retention of particles in a target (size) category. The efficiency required is dictated by the particles or substances trying to be removed. A large-mesh filter may be very efficient at retaining large particles, but inefficient at retaining small particles. Capacity is the ability to "hold" previously removed particles while allowing further flow. A very efficient filter may show poor capacity, causing increased resistance to flow or other problems as it plugging up prematurely and increasing resistance or flow problems. A balance between particle capture and flow requirements must be met while ensuring integrity.
- ^ Cornelis MC, El-Sohemy A (November 2007). "Coffee, caffeine, and coronary heart disease". Curr Opin Clin Nutr Metab Care 10 (6): 745–51. doi:10.1097/MCO.0b013e3282f05d81. PMID 18089957. http://meta.wkhealth.com/pt/pt-core/template-journal/lwwgateway/media/landingpage.htm?issn=1363-1950&volume=10&issue=6&spage=745.
- ^ History of Coffee
- ^ Paulapuro, Hannu (2000) "5" Paper and Board grades Papermaking Science and Technology 18 Finland: Fapet Oy p. 114 ISBN 952-5216-18-7
- ^ "Coffee Filter and Diatomaceous Earth". Princeton. http://www.princeton.edu/~pccm/outreach/scsp/mixturesandsolutions/diatoms/coffee_filter.html.
- ^ "Seal face lubrication". McNally Institute. http://www.mcnallyinstitute.com/09-html/09-07.html.
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