One of the suggestions came from my friend Dave who has some experience with this sort of problem. Per Dave:
Go to a Dollar Store and pick up a big cheap thing of cayenne pepper. Mix in a great deal of it with your bird food in the bag that you keep in the house (I'd say we used a good 1 1/2 cups per 30 lb bag). They'll try once but after that they generally stay off for good. As they start leaving you alone you can reduce the amount of cayenne you use, but I would say to always continue using it as you never know when they'll come back.
Most mammals, except for my friend Dhiren, don't like this much cayenne pepper on anything. But birds can't taste it. The birds just don't care that it's there!
I mixed the first batch of bird food a little stronger than Dave suggested. I'd have followed his instructions to the letter, but Allison was "helping" me pour the cayenne pepper. When I put it outside my eyes were tearing a bit. I left the top of the bird feeder loose so it would be easy for the raccoons to break in. The next morning, the top had been moved but the bird food was still there!
The birds were completely unfazed. Over the last week we watched as woodpeckers, cardinals, golden finches, morning doves and tufted titmice made their way through the cayenne peppered bird food. Not a drop disappeared at night!
When I refilled on Sunday I'd already backed off to 3/4 cup of cayenne pepper per 20lb bag. Last night there were 3 raccoons on my back deck. They didn't touch the bird feeder.
So that's the answer. To keep raccoons from eating bird food, just mix some cayenne pepper in with the seeds. The raccoons will avoid the food, and the birds are completely indifferent.
Bird Food after 4 days with Cayenne Pepper