 Can you imagine eating a hamburger that is in every way identical to the hamburgers you're used to eating except that it did not come from the carcass of an animal? Well, this might sound a bit like science fiction. Slot-free meats may be available to consumers in the next several years. This type of meat, which can be referred to as cell-based, cultured, or in vitro, is meat that's grown by cell culture rather than inside an animal, and it promises to feed a grown population in a more ethical and environmentally sustainable way. But how exactly is cell-based meat made? A small amount of tissue is extracted from an animal, a biopsy the size of a sesame seed that contains millions of cells. This tissue is placed inside a cultivator that makes the cells think they're still inside the body, so that they do what comes naturally. Replicate and grow into muscle. To enable them to grow, cells are provided with warmth and oxygen and are fed sugars, salts and proteins through the liquid solution they're placed in. Supporters are quick to point out its benefits. It does not involve killing animals. It's potentially more environmentally friendly and it may even be safer for human health. For example, meat from animals can be contaminated with a whole range of intestinal pathogens that can make us sick. This is why it's important that we thoroughly cook and handle it with care. However, meat grown in a bioreactor or from cell culture never comes into contact with intestines and their accompanying pathogens. When it comes to environmental impact, some estimates suggest that cell-based meat could require from 7 to 50 percent less energy and 99 production in land use and up to 95 percent less water when compared to traditional farm meat production. However, scientists still need to determine precisely how much more eco-friendly cell-based meat will be. Estimates of environmental impact depend on what would compare cell-based meat production to. There are many ways to raise livestock and different methods can influence the environment differently and some of these actually have positive impacts on the ecosystems. Of course, production of cell-based meat does face some challenges. One major challenge is finding just the right nutrient-rich liquid to grow cell-based meat in. At the moment, this liquid is an expensive serum made with animal blood and it is harvested from unborn calves. This solution is ethically and economically not feasible in the long term and several companies are now looking for suitable plant proteins to replace this animal-based serum. Another challenge is what people think about cell-based meat, both in terms of their preferences including whether it will look and taste right to them and how readily people might accept a new way to produce the food that they eat. At the moment, cell-based meat can take the form of hamburgers, patties and nuggets but replicating structure and texture of the other meat products we're used to such as steak is not yet possible. There is also the challenge that many people might find the idea of meat grown in the lab and appetizing or unnatural and some surveys show that consumers aren't sure about this new way to produce meat. Yet, there are plenty of people who are intrigued by the idea of meat that does not involve killing animals. For cell-based meat to be successful, consumers will need to know that it's safe and healthy and they'll need information they can trust on what it is, how it is made and what benefits it offers to them, the animals and the environment. At the end of the day, though, we cannot afford not to make changes to how we produce our food. New approaches are not only necessary because of ethical considerations but also because supplying the world with enough affordable animal protein may eventually be impossible using conventional farming. By the year 2025, the world population is projected to exceed nine billion people and as it does, meat consumption is estimated to grow at an accelerating rate. With such growth, there is a risk that we won't be able to meet the demands of more and more people unless we develop new technologies and cell-based meat may well be one of them.