Temperature

• The temperature of treated water is acceptable to a majority of target consumers.

Key indicators

• Ambient temperature (15°C to 25°C) is acceptable, unless it adversely affects other water sensory perceptions.
• Water cooled below ambient temperature may be highly valued by consumers.

Notes and exceptions

• Water temperature affects taste intensity and individual preference for water. Drinking water should ideally be cooler than body temperature.
• Temperature preferences are often based on experience and vary by culture. The effect of temperature on preference can be modified by changing consumer expectations about the temperature.
• Since people are probably accustomed to the temperature of their local water source (well, surface, tanker, tower, etc.), this can effect perception of acceptable temperature.
• Evaporative cooling by wetted fabric covers or unglazed ceramic can cool water six to nine degrees below ambient for a noticeable difference, which is desired by some consumers, especially in hot and/or dry climates.

Supporting evidence

• Committee on Military Nutrition Research Food and Nutrition Board, Institute of Medicine US, Marriott B ed. Nutritional Needs in Hot Environments: Applications for Military Personnel in Field Operations. Washington, DC: National Academy Press; 1993.
• Zellner DA, Stewart WF, Rozin P, et al. Effect of temperature and expectations on liking for beverages. Physiology & Behavior. 1998;44(1):61–68.
• Full list of supporting evidence and additional materials.