Black walnut is native to Illinois, and is a tree that provides shade, early fall color and beautiful timber. They also produce a nut crop highly prized for culinary character, adding a rich, distinct, somewhat tangy flavor to foods. Shelled black walnuts are expensive and sometimes difficult to find in stores, as compared to the more commonly available English walnut.
Though black walnut trees are common and nuts easy to find, it's gained notoriety due to the difficulty in getting at the nutmeat or kernal. The persistent nut gatherer must first make their way through a tough hull or husk, then an extremely hard shell and thick, convoluted interior chambers. Extraction of half or even quarter pieces can be difficult. However for those willing to put in the effort, the reward of gathering and processing this native delicacy is well worth the time.
Collection time for walnuts begins late September to early October. Trees can be found in lawns, parks and timber areas. Always ask for permission to pick up nuts on private property. Most people are happy to have them removed from lawns. Check with park supervisors for public land gathering. For equipment, a bucket or bag should suffice, and to avoid bending over, a short stick with an aluminum can attached will work well for sweeping nuts off the ground.
Black walnuts should be harvested once they mature. The test for maturity is softening of the outer husk. If you can leave a finger depression on it, the nut is mature. Most people wait until nuts start to drop before gathering, even though they mature well before that time. Nuts drop naturally over a period of time. For those waiting on nut drop, this necessitates several visits. Dropped nuts are also more vulnerable to squirrel scavenging or lawnmower damage. Thus on-tree picking is recommended and can be advantageous. Limbs can be shaken to loosen nuts, or they can be dislodged with a long pole. There is another advantage to prompt gathering off the tree: if left on the ground to decompose, the nutmeat will become darker and stronger as the husk breaks down. The best quality nutmeat is light in color and has a milder flavor, and this requires that the husk be removed while it is still green and fresh.
There are many methods that can be used to remove green or partially decomposed husks. Most popular is piling the nuts up in a gravel driveway and driving over them a few times. The husk will slip off, but the shell will stay intact. Another method is to drill a one and five-eighths inch diameter hole in plywood or a thin board. Use a heavy hammer to force the nut through, shearing the husk off. A two by four board and a hammer can be also be used to roll a husk off, as well as a heavy foot. Old-fashioned ear-corn shellers have also been used with success to remove husks. When handling and removing crushed husks, always wear leather or rubber gloves, the brown juice stains from the husk are strong and persistent.
Once the husk is off, the nuts should be washed to remove excess juice and hull debris. Methods range from hosing the nuts down to agitation in a bucket. Old tub washing machines and small concrete mixers also work well for this task. Use a ratio of 1:3 nuts to water, and in the concrete mixer, add a few 2-3" diameter rocks to help the cleaning process along. Unfilled nuts will float and can be removed.
After washing, the nuts need to be dried and cured. Without curing, nut moisture is high and flavor is poor. With proper curing, nut keeping quality and flavor will improve greatly. To dry, spread freshly husked and washed nuts out in thin layers in a well-ventilated area. This initial drying may take several weeks. Avoid excess drying and do not put nuts in direct sunlight to dry. The goal is to reach about 8-10% moisture. Once dry, nuts can be stored in mesh bags, burlap sacks or baskets. Keep in a cool, dry place, out of the weather.
Black walnuts have gained a reputation for the hardness of their shell and difficulty of cracking. You may find that your hand-held nutcracker is not up to the job. A hammer, a block of wood, a vise or big rocks are most commonly employed to get the job done. There are special pressure-type crackers designed for black walnuts, which efficiently crack nuts end to end, one at a time. These can be worth the money if you want larger pieces, less crushing of the nutmeat and higher crack-out percentages.
For another way to extract large pieces, try pre-conditioning or tempering the nuts prior to cracking. This involves soaking in water for one to two hours, then drain and keep the nuts moist overnight in an airtight container. The kernels will pick-up moisture and become more flexible and not shatter as badly. If kernels still seem brittle, use a hot tap water soak just prior to cracking to enhance moisture uptake. When using a hammer or vise, always try to crack the nut across its widest dimension. Small nippers or wire cutters can be used to clip the shell interior to free half and quarter pieces. A use of a nut pick will also help in extraction from shells.
Another approach is to crack many nuts at one time. Using a mallet and a burlap or heavy duty sack, place about 100 nuts in it and strike until they are broken into a mass of shell and kernal fragments. Take care to not crush the nuts by striking too hard. The mass can then be sifted by screens to remove fines and large pieces that may need re-cracking. Follow this with hand separation. A good technique is to separate into free nutmeat pieces, shell fragments, pieces that need pick separation, and re-crack pieces. With practice, this can be an efficient method for large volumes of nuts.
Un-cracked and cured nuts will keep best in a cool, dry place for up to a year before becoming rancid. Freshly extracted nutmeat should be allowed to dry for a day or two before refrigerating in a moisture-proof container. Nutmeat can be frozen in jars or freezer bags, and will hold two or more years without loss of quality.
