Photo by dailyinvention/FlickrCC
When I'm in a hotel room or a rental cottage where the proprietor has supplied coffee and a coffeemaker, I have a regular routine.
The normal recommendation is to draw fresh water just before brewing. City water varies considerably, and cities that have been famous for good water, like New York and Seattle, have slipped considerably. I try to buy a large bottled water—like Poland Springs, Crystal Geyser, or Dasani—because bottled water has a slight amount of mineral hardness. Whole Foods bulk water, Aquafina, and various other waters filtered by reverse osmosis that don't have added minerals don't make as a good a cup. I would only use distilled water in severe circumstances.
When I measure the water, I don't fill the carafe to the top. I fill to about 75 to 80 percent to make the brew stronger.
If I've failed to purchase bottled water, I draw the tap water the night before. This achieves two things: the chlorine will partially evaporate, and the temperature will rise to room temperature. The heaters in coffeemakers will raise the temperature a certain number of degrees. They don't have holding tanks like commercial machines. A twenty-degree difference between newly drawn tap water and room temperature will result in nearly a twenty degree increase in brewing temperature.
Next, I turn the machine on before putting any water or coffee into it. The heater and the hot plate get warm, which will raise the brewing temperature for those first several ounces of water and will warm the carafe into which the coffee is being brewed.
(Another possibility would be to run tap water through the machine without coffee. This would warm up the machine. Throw out that water and proceed as above. Still another possibility I haven't tried would be to run your brewing water through once without coffee, then brew with the same heated water. You might get water even closer to proper temperature. The effect of double heating may well reduce its liveliness, but it might be worth a try depending on the circumstances.)
Then I check the weight of the coffee packet. They formerly held an ounce, but lately I've noticed that weight has been trimmed to 0.9 ounces. When I measure the water, I don't fill the carafe to the top. I fill to about 75 to 80 percent to make the brew stronger.
Taking these few steps definitely improves the final cup. It may not be as good as your coffee at home, but it's probably better than the coffee in the hotel restaurant.