Sometimes innovations in cooking seem like they're only for chefs, or at the very least people with the coin to drop on an immersion circulator. Rarely does something hit the market that is affordable, amazing, brand new and totally practical for the home cook. That is exactly how we'd describe the Wonderbag.

Originally invented by founder Sarah Collins in South Africa with the intention of conserving cooking energy in developing nations, this cordless, power-free, gas-free slow cooker might just change the way we slow-cook forever. Although our slow cookers are tried and true instruments in our kitchen, the notion of leaving an electrical appliance running hot while we sleep or leave our homes has always made us a little nervous, to be honest. The Wonderbag removes that worry, saves electricity and -- the best part -- actually works. You start anything you cook in the Wonderbag on the stove (recipes range from beef stew to oatmeal to greens and beyond), bringing your pot to a boil for around five minutes. Turn off the heat, seal the pot and pop it in the Wonderbag for your desired amount of time. A tender beef stew will take about four hours, but you can leave your food in the Wonderbag for up to 12 hours without it falling below a safe temperature.

We got our hands on a Wonderbag and I was so excited to try it that I couldn't pick a recipe from their website. I decided to go rogue and see if I could make a solid vegetable stock in this thing. I followed my usual method -- which involves a freezer bag full of vegetable scraps, herbs, a pot full of water and seasonings -- but once the pot had come to a rolling boil for five minutes, I turned off the heat and transferred the sealed pot to the Wonderbag and left it on my kitchen counter. I'll admit to experiencing a healthy amount of skepticism: to me, a simmering pot is the sign of something that will taste good. But, after four hours, I opened up my Wonderbag to reveal a rich, flavorful stock, that was about twice the volume it would have been if it simmered away on the stove all day (because the Wonderbag conducts a sealed, insulated heat, there is little to no evaporation).

So it saves energy, time, worry and actually works. But there's actually still more good news: for every Wonderbag purchased via Amazon in the U.S. (for $50), a Wonderbag will be donated to a family in need in Africa. There aren't a lot of kitchen appliances we can think of that have quite as much impact on the rest of the world. If you end up getting one, let us know how you're using it. We can't wait to discover more tricks.