All martian colonists will require food, either brought from Earth, or grown in greenhouses on Mars. To ensure a reliable supply of food, food production should exceed the minimum required by a substantial margin. The excess food can be stored for future need through food preservation techniques.
Freezing is the most cost effective preservation method, due to the ambient external temperature. Food could be stored in containers external to the colony, probably in near underground, where the temperature is constant during the year.
Refrigeration requires the maintenance of food temperature within a narrow range of temperatures. This technique is more complecated than freezing, and requires energy input and control to maintain correct temperatures.
Dehydration would require a method of removing the moisture from food. Smoking is a method of dehydration that also inparts flavors to the food.
Freeze Drying combines freezing with dehydration. The low ambient pressure could be harnessed for this preservation method.
Special atmospheres such as nitrogen or noble gasses can retard the growth of aerobic bacteria.
Heat is used to kill microorganisms.
Salt has been used for millenea to preserve meats. It dehydrates the food and inhibits the growth of microorganisms that could spoil the food or cause sickness.
Fermentation preserves foods such as cheeses, yogurt, and many other foods.
Weak acids, such as lactic acid, can be introduced artificially or naturally through fermentation.
Manufactured chemical preservatives, or artificial preservatives, are used in manufactured foods. They may require more effort to produce than a settlement is willing to spend, especially with the other low-tech options available.
Uses for Excess Foods
Excess food can be traded to other settlements.
Excess food can be fed to animals such as fish.
- What is the temperature in near underground, where the temperature is constant during the year? While on Earth the temperature is about 8°C in 2 m depth, the temperature under the Martian surface should be near the average atmospheric temperature of -63°C. Are there measured valued available from the Mars probes?