PhillyEarth was awarded with a $1,000 grand prize at a local crowd-sourcing event called Philly Stake, for our idea to build a pizza oven out of cob. What is cob you might ask? Cob is a natural building material comprised of specific ratios of straw, sand and clay. When mixed together, these materials make an excellent and inexpensive way to build houses and more importantly for us, pizza ovens. We invited our friend and expert Natural Builder, Sigi Koko of Down to Earth Design, to come out and teach us how to build with such an amazing material! The entire build took us 5 days to complete. Getting to celebrate with homemade pizza cooked in our new cob oven using fresh veggies from the garden, was the best reward!