What Are Walnuts?

Juglans spp - the walnut is a large and spreading, rounded tree with robust green leaves borne on branches that tend to droop and curl downwards. It is superficially similar to - and from a distance, may be mistaken for - Horse Chestnut, however, the latter has a different arrangement of leaves and the fruit cases are usually spiny, whereas walnut fruits are smooth.

Close up, the walnut tree is unmistakable - the leaves are divided into leaflets arranged in opposing pairs (leaves arranged this way are known as pinnate.

The leaves are strongly aromatic when crushed or rubbed, having a spicy scent - but be careful - the sap will stain hands and clothing (more on this later).

I picked about a kilo of the green nuts - which was about all I could pick from branches close enough to the ground.

It's important to get them before the nut shell hardens - the end of June is the limit here in the South. They should be easy to cut in half (see inset) and the shell, immediately inside the green casing, should be crisp, but not hard or woody.

To prepare the nuts for pickling, they must be pricked all over with a fork or skewer.

Rubber gloves are absolutely essential here - the juice that comes out of the nuts will stain almost anything it touches (certainly including skin and clothes) to a deep yellow-brown colour - and it doesn't wash off. Never attempt anything without the gloves.

Next, the nuts must be brined for two weeks, changing the brine midway.

For one kilo of nuts, use 100g of table salt and enough cold water to just cover them - dissolving the salt into about 500ml of cold water first, pouring this over the nuts, then topping up with plain water.

Almost immediately, the brine begins to draw out juice from the walnuts.

The container (glass is best - anything else may stain) is then covered and left in a cool place for a week.

At the end of the first week, the brine has turned very dark brownish yellow and has an oily sheen on the surface - it looks horrible, but this is normal.

There's also a peculiar smell - a sort of spicy metallic aroma - this too is quite normal

The nuts are drained and rinsed - they've turned from fresh green to khaki with black patches.

At this point, any nuts that are spoiled should be easy to spot - and they can be picked out and discarded.

Then they should be covered with a new solution of brine (same mix as before) and left for the second week.

At the end of the second week, the brine should again have turned dark and murky - the nuts are drained and rinsed again. This time, they look darker and may be a little wrinkly.

The dry nuts are spread out on a tray and left in a cool airy place - they will turn completely black - then they'll be ready for pickling.

Two days later, the walnuts are dark purplish black, softish to the touch and slightly wrinkly or dimpled in places.

Time to get them pickled.

At this stage, they should be dark brown all the way through and should cut as easily as butter.

They need to be handled a bit carefully from here on, as they will break apart easily if roughly treated.

The walnuts are packed into clean jars, ready for pickling.

The jars need to be thoroughly washed and rinsed, but don't especially need sterilising - the acidity of the pickling syrup will prevent spoilage.

The ingredients for this are: 500ml of malt vinegar, 225g soft light brown sugar, 125g of molasses sugar and some whole spices.

This spice pack was intended for making mulled wine, but it's perfect for pickling, containing cinnamon, cloves, cardamom and other whole spices.

The syrup is made by placing all of the ingredients in a pan, heating until boiling, then simmering for 15 minutes to allow the spices to infuse.

It is necessary to stir the mixture at the start, until the sugar is all fully dissolved.

The syrup is poured over the nuts in the jars, right up to within a half centimetre of the rim.

If this was a chutney, it would be necessary to strain out the spices, but as the nuts will be picked whole out of the jars, the spices can be left in to infuse further - they can just be shaken off before the nuts are eaten.

After a few hours, it may be necessary to open up the jars and top them off with a little more syrup, as the walnuts will soak some of it up.

As with any good pickle, this one needs to be left alone to mellow and mature - it'll be ready for first tasting around Christmas time, but will keep almost indefinitely - continually improving with age.

While we're waiting, here's what they should look like when they're done - this is one from a batch of pickled walnuts I made in 2007 (served with pork pie and salad).

They're spicy (both from the added spices, and their own natural spicy taste), salty, tangy and sweet - all at once. This is a really substantial and satisfying pickle.

Walnuts

I will, of course, try to get to these walnut trees at the right moment to enjoy some of the ripe nuts in late summer - I'm not really sure how successful this will be though.