In the last post about the Indiana corn, I showed a picture of an ear of corn. You may have noticed that it doesn’t look exactly like what you expect from an ear of sweet corn. That’s because it’s not sweet corn! That corn is called field corn. There is a difference between sweet corn and field corn – the type of corn, how it’s harvested, and how it’s used.
The field in the photo above is planted with field corn on the right, and sweet corn on the left. (There’s more field corn in the back left.) Can you see the difference in the plants? The field corn is much taller and has fuller leaves than the sweet corn. The sweet corn looks sort of short and spindly. (Yes, it’s dry, but this is pretty close to how the plants will look in a normal year, too.)
Sweet corn is harvested when it looks like this. The silks at the top of the ear are brown, so we know that the kernels inside are as developed as they are going to get. The leaves that wrap the ear are nice and green (maybe a little bit of brown around the outside edges). The ear is still held tightly against the main stalk.
When you get your sweet corn home and shuck it, it looks like this. Yellow and/or white kernels, nice and round and plump and looking delicious!
Lots of sweet corn is sold fresh on the cob. It is also frozen or canned.
Field corn is used very differently than sweet corn. It’s not nearly as sweet as sweet corn, so it doesn’t taste very good right off the cob. Field corn will be processed into corn meal or corn flour, and then used in foods that have corn as an ingredient. Simple examples are tortilla chips or corn flakes, but lots of other foods also contain corn. Field corn can also be used to feed animals or to make ethanol.
Some field corn is called seed corn. This will be used as seed for next year’s corn crop instead of used for food this year.
Field corn is not harvested as early as sweet corn. The goal is for the corn to start to dry while it is still on the ears. Corn is very high in moisture, and it needs to dry out quite a bit before it can be processed. This corn is starting to dry out, but isn’t ready for harvest yet.
Farmers are looking for a few things to tell them that field corn is ready to harvest. First, the silks at the top of the ears turn dark brown. Then the shucks around the ears turn brown. Then the rest of the corn plant dies and turns brown. Finally, the ear falls so that instead of being held up against the main stalk, it drops down so the silks are pointed at the ground. This is how farmers know the corn is dry enough to harvest.
The kernels of field corn are darker yellow and are larger than kernels of sweet corn. You can see that some of these kernels have a dimple, or a “dent”. This means the kernels are starting to dry out. (Field corn is also sometimes called “dent corn” because of the way the kernels look when it is harvested.)
This ear of corn isn’t quite ready to harvest, but it’s getting close. This usually happens in October or November around here, so it’s very strange to see the corn getting close to harvest time in August!