It’s been a pecan week this week! We had a good meeting followed by an awesome pruning training. We wanted to do this a few weeks ago, but cold weather got us. We still had a good number of folks that wanted to see Dr. Wells destroy these 3-year-old Ellis trees.
Dr. Lenny Wells had a request to share information on storing pecans. There are two key factors affecting storage of pecans are moisture and temperature:
Large lots of nuts should be dried with a mechanical drier, usually in harvest wagons designed for this purpose. Heated air is forced up through the trailer, drying the pecans from bottom to top. Normal mechanical drying temperature is about 95 degrees (100 or more will negatively affect the kernels). Relative humidity of the drier air should remain below 60%. Air flow should be 90 cubic feet per minute (cfm) per sq. ft. of drying area. Drying time will depend on the level of moisture
For smaller quantities of nuts for which mechanical drying is not possible:
Pecans should be brought to a moisture level of about 4.5% as soon as practical after harvest. When small quantities (100 pounds or less) of fully mature, freshly harvested, in-shell nuts are stored in woven sacks, in a well ventilated building, they will dry and cure naturally in about 2 weeks when the weather is dry (60% or less relative humidity).
When nuts are harvested early in the harvest season or have a moisture of 8% or more, or when the relative air humidity is 80% or higher for several days, or when no proper storage area is available, mechanical drying is preferred.
If moisture content of the nuts is 5-6%, 100 lb bags of in-shell nuts can be spread on dry floors in a room in which dry air (60% or less relative humidity) is rapidly circulated over the bags for about 12 hrs. When using this method the bags should be turned about every 3-4 hrs.
Pecans should be stored at 4.5% moisture and 32-34 degrees F at 65% relative humidity. In-shell nuts generally decline in quality more slowly than shelled nuts. In shell and shelled nuts stored under these conditions may remain acceptable for up to 3 years, although quality may suffer somewhat after 18 months. Temperatures below 32 degrees may protect pecans for as much as 3 years; however, they will become more dry and brittle the longer they are kept at freezing temperatures. Bear in mind that pecans may absorb flavors and odors from other stored materials.