See The USDA Complete Guide to Home Canning and An Introduction to Canning Safely. Saturday turned into a busy canning day. The first sweet corn was ready, and in this warm weather it wasn't going to maintain its prime sweetness for long. It's a good idea to have all your canning gear setup and ready to go before you harvest. You may even want to start your blanching pot heating up as you finish picking.
Sugar starts converting to starch very quickly once the corn is picked.
Typically a bushel of corn is more than enough to do a canner load of six quarts. For best flavor, corn should be harvested before the kernels become too starchy. One the other hand, if you harvest corn with kernels that are still quite small, your yield will be substantially reduced. Don 't harvest before corn is at the milk stage. When you press your fingernail into a kernel, the fluid that comes out should be milky white.