About 1960 maybe earlier, Coffee brewers institute offered classes in coffee brewing. Upon completion of instruction, we were awarded a 1/2 gold colored coffee cup and hung it over the entrance to the bar. Tap water should be fit to drink. Never boiled or perked. 210 degrees. No more. Fresh coffee in a can or bag is near unattainable unless you find fresh roasted beans & grind 'em yourself. To test, take a pinch of coffee and roll it between thumb and forefinger. You should feel the oil. Second test, place a hot cup of coffee across the table and you can see a thin film of oil on the surface.