If you determine you have problems in one of your bins where you still have corn stored, you need to take action. Richard Stroshine, corn quality specialist at Purdue University, recommends acting now, and removing corn from the bin until you get at the problem corn. This will likely be easier if you have temperature cables inside the bin, and have identified a problem area based upon rises in temperature. If you didn't core the bin or remove the peak, odds are you could have problems in the center of the grain mass.
Coring the bin could still help if you didn't do it last fall, Stroshine says. This usually involves removing a load or more of corn from the bin. In a bin with a flat bottom, the gain removed by coring generally comes from a cylindrical region directly above the outlet in the center of the bin. When you remove that grain, the corn with the odds of having the most fines goes with it.
In bins with false floors, once you remove about half the corn from the bin, you may be able to dry the remainder of the corn relatively quickly. It's possible that if you didn't dry the corn all the way down in the fall, it may be at moisture contents higher than you would want for storage at this time of the year. Drying the remaining corn should shut down any mold activity going on in the bin in the grain mass.
To dry quickly, you need around 2 cubic feet per minute per bushel of air flow. If your airflow capacity is typically 1 cfm per bushel on a full bin, then airflow once the bin is half empty should be at least 2 cfm per bushel. You're not going to be able to accomplish this in older storage bins equipped with very small fans. You need a bin designed to move air through the grain with a higher horsepower fan.
If you know that the corn never dried below 16% and you still want to hold it until May or longer, Stroshine recommends either selling it sooner, whether you want to or not, or finding a way to dry the corn. You could dry it with natural air in the bin if you can supply 2 cfm per bushel of airflow. Or you could send the grain through a high-temperature dryer to pull down moisture, then into another bin. Doing nothing is not a smart option, he concludes.