Food preservation is a way to keep fresh food from spoiling and most cultures developed various methods out of necessity to keep their foods edible before freezers and refrigerators existed. Different methods of preservation include refrigeration, drying, salting, canning, fermentation, chemical additives and packaging materials. In addition to preservation, we continue to use many of these techniques today because they also result in delicious food products! Pickles, dried fruit, canned beans, and beef jerky are just a few examples that you probably eat!
In extreme environments, such as outer space, food has an even greater chance of spoiling. We need to make sure food lasts for a long time since there aren’t any grocery stores in space (yet!) and astronauts have to wait for cargo resupply missions to get more. That's why most space foods currently rely on pre-packaged preserved foods that have been freeze-dried or canned and have a long shelf life. Space travel provides many opportunities to use our rich and diverse cultures of Earth-based food preservation practices. For example, the ancient food preservation technique of fermentation could be used to reduce food waste on the ISS, with astronauts fermenting their space food leftovers to “grow” more food!
In the future when we have longer and more frequent trips to space (imagine a two year trip to Mars!), astronauts will rely on closed-loop food systems. This means that we need to use everything—including scraps and leftovers—to get rid of garbage and waste. For example, we can use our food scraps to make compost for fertilizing plants, or use leftovers as fermentation starters to make new types of food. Food preservation is one way of creating a more sustainable system design in space as well as on Earth!
Mission
Imagine that your house is in outer space! You are now an astronaut and need to make sure that you have enough food for the coming weeks…
Mission: Imagine that your house is in outer space! You are now an astronaut and need to make sure that you have enough food for the coming weeks . . .
[1] Check your food supplies. Go on a scavenger hunt around your kitchen and pantry to take an inventory of some of your food supplies and write down how long they will last (find the date stamped on the container or estimate how long you think your fruit/vegetables have until they spoil) and whether the food has been preserved already (if it’s in a jar, can, or outside of your fridge it probably has). A list with columns for item, date, and preservation method will help you keep track of everything!
[2] Circle items on your inventory that have not been preserved yet. Your next job is to identify a way for you to preserve it so it won’t spoil! Think about ways your family and friends usually preserve foods (especially during the summer season)!
[3] Preserve your foods. Try using one of the methods of preservation with the recipes we have below to put the principles of food preservation into action. Pickling and dehydrating are both great ways to save food and even create new flavors in the process! If you don’t have the interest or ability to do these recipes, you can note the methods you would use for the non-preserved items on your inventory list!
Fun fact: Do you know which astronaut has spent the longest consecutive time in space by a US astronaut, and for how many days? Find out here! How many cargo resupply missions do you think bring food to the International Space Station each year?
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