Boiling can be seen without the help of a thermometer, and by this time, the water is disinfected. Though the boiling point decreases with increasing altitude, it is not enough to affect the disinfecting process. "Boiling" is the method of cooking food in boiling water or other water-based liquids such as stock or milk. Simmering is gentle boiling, while in poaching the cooking liquid moves but scarcely bubbles. The boiling point of water is typically considered to be 100 °C or 212 °F. Pressure and a change in the composition of the liquid may alter the boiling point of the liquid.
Vienna Standard Mean Ocean Water point of VSMOW water is slightly less, about 99.974 °C. This boiling–point difference of 16.1 millikelvins between the Celsius scale's original definition and the current one (based on absolute zero and the triple point) has little practical meaning in real life because water's boiling point is highly sensitive to variations in barometric pressure. For example, an altitude change of only 28 cm (11 in) causes water's boiling point to change by one millikelvin. Vienna Standard Mean Ocean Water Vienna Standard Mean Ocean Water (VSMOW) is a water standard defining the isotopic composition of fresh water. It was promulgated by the