Pine nuts are worth the effort
Pine nuts are the edible seeds of various types of pine trees. There are around 20 species of pinus that produce kernels large enough to bother extracting but the one most commonly grown in New Zealand is the European stone pine, or Pinus pinea.
They are easy to propagate from seed, don’t require much in the way of pruning and are basically untroubled by pests and diseases.
Pinus pinea grows best in areas with hot, dry summers and cool, wet winters but are coldhardy down to -22 degrees Celsius.
They take five to six years to start producing cones. They don’t reach full productivity for about 40 years, but a mature tree should yield about 5-15kg of kernels a year.
One reason for growing your own pine nuts is that they’re expensive to buy. But the major problem with growing your own pine nuts is the difficulty in extracting the edible kernels from the cones.
The first step is relatively easy: the scales of the pine cones naturally open in the sun, allowing the stone in each one (the seeds in their hard seed coats) to be released. But getting the edible kernel out of the seed coat is not quite so simple.
Commercial pine nut grower Lee Paterson, general manager of Pinoli in Marlborough, says extracting kernels from the hard seed is no simple task.
The extraction method used in its factory has about 50 separate steps from cone to kernel. The process takes place in a fully food-safe environment and would be impractical to try to emulate on a small scale. For small-scale home harvests, Lee explains the basics of the age-old Greek and Roman method. 1 Pick the green cones from June 1 onwards. Have picking finished before November when the cones start opening on the tree.
2
Store the cones in a ventilated area. Warm is better but really any shed or room with a door or window open will do.
3
Wait until the hottest, driest time of the year, put the cones in the sun and let them open (full sun is important). This will take anywhere from one day to one week. Sweep and roll them around and even stamp on them if you like to get the seed out of the cones. Sweep the seed apart from the cones and then sprinkle the cones well with water on the next hot day. This will cause them to close rapidly, then open again quickly, which releases a good percentage of the remaining seed.
4
Clean the seeds by putting them in a sack or cloth bag and rolling it around so the seeds rub against each other. Then on a hot day, tip the seeds into a bucket of water. The dead seeds and cone waste will float and the live seeds will sink. Skim off the debris and tip the clean, live seeds onto the concrete in the sun to dry properly. It is important that they dry properly before being soaked in the next step.
5
Soak for 10-12 hours in water, then put them in super-hot sunshine. When a hot day is predicted, start soaking the night before. Lay them out on some black plastic or some other clean dark surface and leave them in the sun. This will cause the seed to split like a pistachio seed. Roll them with the palms of your hands on the concrete or some other hard surface and the seed shell will split, releasing the kernel. 6
Use 70 per cent warm or even hot water in a bucket and dissolve 30 per cent salt. This will allow you to float off the kernels and the shells will sink. Rinse and dry. The need for drying at this point is dependent on how much water they take up in the salt separation process. If you are quick about floating them off and rinsing, they shouldn’t need much drying. Try flexing a kernel; if it bends it could do with some more drying, if it breaks easily it’s dry.