What it takes: producing cobnuts

Categories: Expert guidance

Edward Lade of seasonal trader Nut Farm and his supplier Richard Dain on growing cobnuts

Interview: Viel Richardson

What is a cobnut?
Richard Dain: It’s a type of hazelnut. Actually, there are several varieties of cobnut. When I took the decision to grow them commercially at Hurstwood Farm, I planted six varieties in ‘platts’—the name for a cobnut orchard—to see which worked best here: the German gunslebert, the American butler, the spanish long (which turns out to be the same variety as the Kent cob), the ennis from France, tonda di giffoni from Italy and gustav zeller from Holland. Along with the Kent cob, the gunslebert and butler were the ones that thrived, so those are our main crops, but we still produce some of the others, too.

Edward Lade: The nuts come from all over, but the name cobnut is specific to southeast England. The Americans call them filberts—traditionally, St Filbert’s day is the first day of the hazelnut harvest. The French call them noisettes.

Are pests a problem?
Richard: The number one pest is a small maggot called a weevil. It bores its way into the young bud and starts eating the kernel. Another problem is bud mites, which are distributed by flying birds and insects and can have a severe impact on the crop. The mites get inside the newly formed nut bud and start eating. That leads to either a deformed nut or no nut at all.

Edward: Grey squirrels damage the trees and will pick and discard several immature nuts for each one they actually eat. The only real protection is to grow more nuts than they can take! Richard has a policy here of not interfering with the wildlife that comes onto the farm. He leaves foxes, birds, badgers, even the squirrels, alone.

You use different nuts for oil and for eating. Why is that?
Edward: It is a question of crop size, oil content and flavour. The gunslebert and butler trees produce consistently high yields and have a high oil content, which makes them great for oil. But if you dry-bake them for eating, the flavour just isn’t there—they’re not bad, but they’re not great. The Kent cob is the opposite: they don’t produce high yields and have a lower oil content, but when baked they’re delicious. Kent cobnuts were the original snacking nuts for Victorian gentlemen—huge numbers were sold in London.

Are they easy to process?
Edward: No, there is quite a lot that needs to happen. Cobnuts grow a covering husk that has to be removed, which is quite difficult, particularly with the Kent cob. We do have some machines that do this, but the nuts still need a visual inspection afterwards.

What happens once the husks have been removed?
Richard: First, you have to ensure that the nut does not grow fungus while being stored. That means lowering the internal moisture content to a specific percentage, in a strictly controlled manner. If you don’t do this properly the flavour deteriorates sharply, as you can actually concentrate some of its less pleasant aspects. We then roast them, which really improves the flavour, then crack the nuts to remove the shells.

How do you do that?
Richard: I realised soon after starting that I had to design my own nut cracking machine, because the commercial ones were all far too large for our levels of production. The machine cracks the nuts open and then uses blowers to separate the kernels from the shells, which fall into different bins. You still have to go through the kernels to check for any pieces of shell, but it is a lot quicker and more effective than shelling all the nuts by hand.

So far, the process has been the same for all the nuts. Is this where things diverge?
Edward: Yes, the kernels for the oil are now ready to be crushed, but the Kent cobnuts for eating need more processing. We need to go through them again by hand to ensure there are absolutely no pieces of shell. We also remove discoloured kernels, ones that have been damaged by insects, or any that look underdeveloped.

How is the oil made?
Edward: The shelled kernels are fed into a screw press, then slowly crushed to extract the oil. They are not crushed between plates but forced through a metal tube with a rotating screw thread inside. The action of the thread crushes the nuts, extracting the oil, which falls into the container below. We then store the oil in large containers and leave it to settle for two or three weeks before putting it through a filter. This gives us a cold-pressed oil with a perfectly clear golden colour. It is absolutely virgin, unrefined, top quality oil.

It all seems like a lot of work.
Edward: It is. The nuts are visually checked about four times and manually sorted twice. There are around 10 different processes that take us from the nut on the tree or on the ground, to the kernels in the bag or the oil in the bottle. That is why it isn’t the cheapest oil you can buy.

What do you use the oil for?
Edward: It is very versatile. Sautéed potatoes come out golden and crispy and not greasy. You can fry with it and get a mild nutty flavour coming through.

Richard: It is also very good in salads because of that hint of nuttiness. Really, you can use it for anything that you would otherwise use a good olive oil for.