I keep waiting for the jar to explode as he seems to tighten the lid on his starter more than he should. That is a lot of starter to store and more than Ed Wood would approve of as he recommends a two cup mason jar.
Steve the Bread Guy shows you how to make a sourdough starter from scratch. You'll need a few potatoes, some water, 2 tbsps of honey, 2 tsp of salt and 4 cups of flour. This starter will allow you to make sourdough bread at home.