Jam and jelly are great ways to preserve blackberries, whether bought or foraged. But this year Ive decided to pickle them with brilliant results

Recipe writing involves a lot of second-guessing about the weather. A column about ice-cream in July, say, is as likely to appear on a cold-snap Saturday as to melt seamlessly into a balmy weekend. But an understanding of how the weather affects our produce puts us on firmer ground. According to the Woodland Trusts Natures Calendar survey, which asks the public to record the signs of the changing seasons, ripe blackberries were reported in only 31 locations by 1 August this year (there were more than 300 in 2015, and as far north as Newcastle). This years colder-than-average spring held back the plants leafing, which in turn delayed the ripening of the fruit.

So when I finally got hold of some blackberries this year, my response was to suspend them in time. Jams, preserves and jellies are all great ways to spread your blackberries over the season, but this year I opted to pickle them, turning a few punnets of fruit into a jar that will last the best part of three months. They also freeze well (handy if you want to file away the crumble recipe until autumn), but rather than freezing the berries as they come, instead spread them out on an oven tray lined with baking paper, then freeze. That way, theyre guaranteed to be frozen whole, rather than squished together; once frozen, simply transfer them to a bag or container to lie, ever so reliably, in wait.

Pickled blackberries

This makes more than you need for the duck or salad recipes that follow, so try mixing the leftovers with herbs and serving with grilled mackerel or salmon, or serving them with meat, especially bacon or roast partridge; they also go well with goats cheese. Makes one 750ml jar.

150ml red-wine vinegar
180ml water
15 juniper berries
2 bay leaves
Shaved skin from 1 small orange
75g caster sugar
1 tbsp flaky sea salt
320g fresh blackberries, gently washed and left to dry

Put everything bar the blackberries in a small saucepan and cook on a medium-high heat until the sugar and salt dissolve and the liquid is just coming to a boil. Take off the heat and leave to cool completely.

Put the blackberries in a sterilised jar you want them to fit snugly, with a 2cm gap at the top of the jar then pour over the cooled liquid, making sure the berries are fully submerged (press them down gently with a clean spoon and, if need be, weigh them down with a small saucer). Screw on the lid and leave at room temperature for five days, by which time theyll be ready to eat. Store in the fridge, where theyll keep for up to three months.

Roast duck with pickled blackberry and mint salsa

One duck serves two generously, but you could always double the duck element and roast two at the same time on two trays, to serve four to six. If you do so, youll need to increase the quantities for the sauce and salsa by only a third or so.

For the duck
2 tsp juniper berries
Flaky sea salt and black peppercorns
1 whole duck, including giblets (2kg)
1 large orange, cut into 8 wedges
2 bay leaves
15g thyme sprigs
2 cloves garlic, peeled and crushed

For the sauce
1 duck neck (from the giblets)
2 tsp plain flour
1 tbsp duck fat (from the roasting tin)
1 banana shallot, peeled and roughly chopped
5g thyme sprigs
1 clove garlic, peeled and crushed
300ml blackberry pickling juices
200ml chicken stock
1 tbsp maple syrup
Flaky sea salt
For the blackberry salsa
180g pickled blackberries
5g mint leaves, finely chopped
1 tbsp olive oil

Heat the oven to 200C/390F/gas mark 6. Put the juniper berries in a spice grinder with a teaspoon and a half of flaky sea salt and half a teaspoon of peppercorns. Blitz to a fine powder, then rub all over the skin of the duck, including the wings and legs. Put half of the aromatics the orange wedges, bay leaves, thyme and garlic inside the bird and scatter the rest in the base of a high-sided roasting tray. Lay the duck on top breast-side up, then roast for an hour, basting every 20 minutes. Turn down the oven to 180C/350F/gas mark 4 and cook for 30 minutes more, basting halfway through, until cooked, then take out of the oven, cover with foil and leave to rest for 10 minutes.

Half an hour before the duck is cooked, start on the sauce. Put a medium saute pan on a medium-high flame, and add a tablespoon of the fat from the duck roasting pan. Toss the duck neck in flour and add to the hot pan with the shallot. Cook, stirring, for three minutes, until the neck is seared all over and the shallots are golden-brown, then add the thyme and garlic, and cook for another minute. Pour over the pickling juices, stock and syrup, bring to a boil, turn the heat to medium and simmer for 15-20 minutes, until reduced by two-thirds and the consistency of a thin gravy. Strain into a small clean saucepan, discarding the neck and aromatics, bring to a boil on a medium-high heat, and leave to bubble away for five minutes, until the sauce is thick and theres 100ml left in the pan.

Just before serving, mix all the ingredients for the salsa in a bowl.

Carve the duck breasts and lay on two serving plates; carve off the legs and put one on each plate. Spoon the salsa alongside and finish with a drizzle of sauce over the duck. Serve with the remaining sauce on the side.

Pear and blackberry crumble

Apples and blackberries are a crumble match made in heaven, true, but pears work well, too. Ive used williams here, but any sweet, ripe pear will do. Serves six.

450g fresh blackberries (or frozen and defrosted)
3 large ripe williams pears, peeled, cored and chopped into 2cm pieces
75ml marsala (or other sweet wine)
80g caster sugar
1 tbsp corn flour
tsp ground allspice
tsp ground cinnamon
tsp freshly ground nutmeg

For the crumble topping
80g unsalted butter, fridge-cold and cut into 2cm cubes
100g ground almonds
90g plain flour
80g soft dark brown sugar
50g rolled oats
1 pinch salt

Heat the oven to 160C/320F/gas mark 2. Mix the blackberries, pears, marsala, caster sugar, corn flour and spices in a bowl, then tip into a high-sided 23cm x 18cm baking dish.

Put the crumble ingredients in a medium bowl, then rub together with your fingertips until the mix resembles coarse breadcrumbs.

Sprinkle the crumble over the fruit, so its completely covered, then bake for 40 minutes, until the crumble is browned and the fruit is starting to bubble up at the edges. Cover with foil, cook for 15 minutes more, until the fruit juices bubble vigorously to the surface and the crumble is crisp on top, then leave to rest and cool a little before serving warm with some ice-cream or yoghurt alongside.

Bittersweet peach and pickled blackberry salad

Read more: www.theguardian.com