How to bake bread in space


June 3, 2012

Sam Wilkinson has come up with a way to make bread within the limitations of a spaceship’s galley (Photo: Shutterstock)

Sam Wilkinson has come up with a way to make bread within the limitations of a spaceship’s galley (Photo: Shutterstock)

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Space travel can be boring. Voyages to Mars or the Asteroid Belt may sound exotic and exciting, but the fact is that most of the time there’s not much to see and not much to do. Wouldn’t it be great if morale on these long missions could get a boost by a reminder of home like fresh baked bread? Thanks to NASA’s “Space Apps” program, that might one day be a reality. Sixteen-year old “citizen scientist” Sam Wilkinson has come up with a way to make bread simply and efficiently using carbon dioxide and a slow cooker that is designed to work within the limitations of a spaceship’s galley.

But this isn’t just a matter of astronauts sitting down to a breakfast of fresh, hot bread groaning with butter and jam (nice though that may be). The process also addresses a very serious problem as man ventures into deep space: how do you carry enough food to feed a crew on long voyages? Up until now, the cuisine on manned missions has consisted of pre-prepared, pre-packaged meals. They may have seemed like something off the menu of the future during the Gemini and Apollo missions, but from then right up through the missions aboard the International Space Station, it’s all just box lunches.

And that’s the problem. Pre-packaged meals take up a lot of space and the packaging adds a lot of weight. That’s fine for short missions in low-Earth orbit, but on a mission to Mars that may last two or three years, that’s a lot of plastic trays and squeezy bags to cart along. One answer to this is to carry food as raw, bulk material like on maritime ships. In other words, a Mars mission would ship frozen sides of meat, containers of dried peas, No. 10 cans of powdered eggs and sacks of flour - or better yet, unground grains. But in order to do that, future spaceships will need proper galleys and astro-cooks will need to know how to prepare food in zero gravity with the limited resources available on a spacecraft.

The science of bread

Bread is pretty simple. It’s basically just flour mixed with water. If you take this, flatten it out and bake it, you get an unleavened bread like a matzo or a tortilla. But if you want something more like a loaf of bread, you have to make what’s called a leavened bread. The key part of baking leavened bread is getting it to rise. If you don’t manage this, you end up with a freshly baked brick. This is usually accomplished by adding yeast. If the temperature is right and the proper amount of salt is added to control the process, the yeast cells will feed on the sugars, start to reproduce and as they do so, they give off carbon dioxide gas. This gas is trapped by the gluten in the dough, which forms bubbles and the dough starts to rise.

The alternative to this is using a chemical, such as baking soda or baking powder, both of which use sodium bicarbonate to produce carbon dioxide and are generally used in quick-rising breads, such as cakes or biscuits.

This has served bakers and householders very nicely for some six thousand years, but baking bread in space has its own problems. Any spaceship designed in the near future is going to be small, cramped, provide very small amounts of electrical power, ration cargo space like it was gold wrapped in gold and won’t have a galley anything like the one on the Starship Enterprise. It will very likely be some tiny, underpowered alcove intended to do too much with too little. Therefore, baking bread in such an environment has got to be as efficient as possible - more bread machine than artisan bakery. More important, it has to be able to work in zero gravity. All of this puts both yeast and any chemical leavening agent at a disadvantage. For one thing, the chemical version needs to be carted along, which adds weight. Yeast doesn’t necessarily have this problem, but the alternative is cultivating it during the mission, which may not be possible in zero gravity or be logistically feasible.

Space bread

This is where Sam Wilkinson’s process comes in. The magic of making bread rise isn’t in the yeast, it’s in the carbon dioxide and you don’t need to ship CO 2 on a manned spacecraft - you’ve got more than enough thanks to all those astronauts breathing. Wilkinson’s idea is to use this “found” carbon dioxide to make the dough rise.

It’s actually very simple. All the astro-baker has to do is mix the carbon dioxide and the water in a sealed chamber at a pressure of about 2.5 atmospheres, which is about that of the average soda bottle. The CO2 dissolves in the water to form carbonic acid and will remain that way so long as it stays under pressure. In other words, you’ve got a bottle of soda water. In another sealed container, you mix the water and flour. Once the mixture has a nice doughy consistency, you release the pressure, the carbonic acid reverts to carbon dioxide, bubbles form and the dough rises. This rising takes about 1.8 seconds, which is much faster than the usual hour or so needed with yeast.

The next step is to take the dough and bake it in a sealed, very low temperature oven at about 120 C (250 F) for one hour and ten minutes. This is a method that is commonly known as “crock-pot bread”. It takes longer than oven baking, but is much more efficient in terms of power. Only between 120 and 280 watts of power are needed to bake a loaf, which is a considerable improvement on the 1500 watts needed in an oven. On a power-strapped Mars ship, this is a significant savings.

Part of the reason for the sealing is to retain moisture and, according to Wilkinson, improve the Maillard effect, which is what forms a proper crust on the bread by the reaction of amino acids and sugars (this can also be done by a quick blast of heat after baking) as well as reducing crumb formation. This is of particular importance aboard a spacecraft because crumbs have given engineers the heebie jeebies ever since the first Mercury flights when they feared the aftereffects of John Glenn’s lunch would end up in the capsule’s machinery. That’s the reason why early astronauts’ sandwich cubes were coated with gelatin and why the ISS only serves tortillas.

At the moment, space bread is still in the proof of concept stage, but it may be that when the first astronauts land on Mars, they’ll have fresh pumpernickel for their sandwiches.

Sam Wilkinson runs us through his space bread baking process in the video below.

Source: NASA

About the Author
David Szondy David Szondy is a freelance writer based in Monroe, Washington. An award-winning playwright, he has contributed to Charged and iQ magazine and is the author of the website Tales of Future Past. All articles by David Szondy

Eat the yeast, CO2 and Bicarbonate of Soda (Rasing agents) have no nutritional value, we may get more out of a nutrient, vitamin rich diet rather than one bulked out with raised bread. If your not descended from Southern Europe/ Middle East, it causes problems with Gluten sensitivity.

Currently I would favour putting the Astronauts into hibernation instead rather than relying on growing food in orbit. At least then later on, later if we send people into space while relying on nutrient recycling, we can put some of them asleep if there is a failure in the hydroponic system. They could survive around 3 months without food, but 2 days without water and no time at all without air. I would rather them get home alive, than to have a nice breadcrust on their space toast.


Without yeast and salt the bread will not be nearly as tasty and nutritious.

Using electricity to generate low heat on a space vehicle is bad engineering. You have all sorts of devices generating waste heat. And a well insulated oven doesn't require as much total energy as a non isolated crock-pot.

Put HEPA filters on all your air intakes will keep the crumbs and the rest of the crud out of the electronics.



You didn't read the article through. They don't want to use raising agents or yeast. And human hibernation is science fiction at this point in time.

Solar irradiation at Mars' orbital distance from the sun is still relatively strong. I don't see why they couldn't use a solar oven on the trip. Solar ovens are already used on Earth, and while solar energy near Mars would be less than half of what's available near Earth, atmospheric attenuation cuts available solar energy at the Earth's surface by half anyway. It evens out. If they have a large Mars expedition spacecraft, a large umbrella-style solar concentrator could give them all the heat they need for cooking while taking up almost no space during launch. Several square meters of aluminized fabric reflector would weigh only ounces.


wonder if it will be anything like space cake.....

Pat Burneson

Re; Gadgeteer - Of course I read the article. The reason I would not go for baking bread in orbit is because of all the problems Sam Wilkinson is trying to solve, because bread in space is not a problem we have to solve, it is a luxury. However hibernation solves the problem of carrying supplies to Mars quite nicely!.

( University of Pittsburgh in 2005 successfully froze and revived 2 dogs. 7 years ago ?, I wonder how well they will do by 2025. Even just a 2 week on off Hibernation cycle would save 50% of supplies needed however I think anyone could only survive being frozen once. The article also mentions on how the research is militarily funded - so we have not heard much of it since.

Most people are more interested in growing hydrophonic plants which you can eat which also recycle urine and create Oxygen. If it was a choice between a solar space oven or solar greenhouse I would grow lettice.


I would have thought this kneaded a little more to it than just mixing in order to stretch the gluten.



It's hardly as simple as you claim. Therapeutic hypothermia can help during cases of trauma, but only for a few hours. Those dogs you reference weren't "frozen" and I don't know where you get "two dogs" from. You can't freeze mammals without massive cellular damage. Some were also suffered brain damage upon revival. As for the Japanese man the article started with, you'll notice there's been no follow-up anywhere on his status. Scientists were skeptical of his doctors' claims that he would recover fully. Some scientists speculated his low body temperature wasn't what saved him, but that his temperature dropped only in the final hours as he was on the brink of death. Besides, he was out for 24 days. If he was eating snow or found some water, that would delay death from dehydration. He has no memory of what he did most of those days. He could have been delirious or maybe just amnesiac. And 24 days is well within the survival period of a person without food so there was nothing extraordinary there. With no food or water at all, a person can survive up to two weeks. Nevertheless, something you fail to appreciate is that all of these reports show mammals with tremendous medical support, something you can't expect on a Mars expedition, and that they were not up and about immediately after being revived, as any astronauts would need to be.


Build it and put it in a supermarket and I will buy one and help iron out the draw backs


Re Gadgeteer;

"Those dogs you reference weren't "frozen" and I don't know where you get "two dogs" from. You can't freeze mammals without massive cellular damage.": I do not have to repeat or justify somone elses reports or articles when they are supported by genuine papers. Please look up University of Pittsburg Safar Center Resuscitation research - I will not revisit this.

This Japanese man is someone in the article I neglected to mention. I also hope like you he is doing well, one of the things about memory loss is that memory is dynamic not static. It is perfectly possible that totally freezing a person solid and rethawing them will erase memory without cellular damage as the mind relys on active electrical means to store memory as much as chemical. Which is why the focus is on Hibernation.

Lots of information on induced hybernation by Asphixiation and poison reducing metabolism to less than 10% with 100% sucessful revival that you forgot to mention from the article.

As to your statement that the subjects received full medical support, that is true. However there is no reason why this should not be available. We already have remote surgery, the Hibernation capsules would contain all the necessary equipment to revive the crew and there should be medical caretaker medical crew available. In fact I would be very disturbed if it was to be absent.


Nice one, Boxpacker! - Doh!

Smithwick McGuinness

re; L1ma

Would you really let a doctor who is several minutes communication lag from you do tele-surgery on you?

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