Frances Bissell tries her hand at making raspberry vinegar and sweet and sour pickled fish.

One of my favourite kitchen occupations at this time of year is to refresh my acetaia - rather a grand term for my collection of bottles of home-made flavoured vinegars – and to make new ones. Herbs, fruit, spices and edible flowers can all be turned into unusual, subtly-flavoured and exotic condiments quite unlike anything you will find on supermarket shelves.

I have bottles of fennel flower, sage, lavender and chilli vinegars and at the moment am making elderflower vinegar. Over the course of the year, the level goes down as I use the vinegar. So now I take each bottle and carefully decant the remaining vinegar and herbs or flowers through a muslin-lined sieve into a jug. In a clean bottle I replace, for example, fresh elderflowers. I then add the vinegar remaining from the previous year, and top up with new vinegar. Thus the vinegar goes through something like the Spanish solera system, the old vinegar ‘educating’ the new vinegar, and fresh ingredients adding their flavour. The only vinegar to which I do not add fresh ingredients is the chilli vinegar; it is quite hot enough after one year, and needs no addition.

White wine vinegar works best, allowing the herbs or flowers to show through. Naturally, the vinegar does darken over the year. At the beginning of the season, it is clear and elegant, as can be seen in the photo of the wild garlic flower vinegar, a new one for me this year. Next to it is raspberry vinegar in the making, of which I always have a bottle on hand.

Fragrant vinegars also enhance today’s recipe for pickled fish, which can be made, if you do not have the ones suggested, with tarragon vinegar, or balsamic vinegar, sherry vinegar or cider vinegar.

Raspberry Vinegar (Makes 500ml)

? 250 g raspberries

? 250 g granulated sugar

? 500 ml white wine vinegar

Mash the fruit in a bowl with the sugar, then pour on the wine vinegar. Stir well, then cover with cling film and leave to stand for four days; stir occasionally. Line a fine sieve with damp muslin, place it over a non-reactive saucepan. Strain the vinegar into the pan. Boil for 10 minutes. Pour the vinegar through a funnel, into hot, sterilised bottles and seal tightly. When cool, label and store in a cool, dark place.

Cook’s notes: that is the standard recommendation about storage, but of course, the vinegar looks so pretty you will want to keep it somewhere it can be admired. And you will probably want to make double quantities so that you can give some as presents. Strawberries, black currants, blackberries and other soft fruits can be used to make fruit vinegar in the same way.

Sweet and sour pickled fish

(Serves 6)

? 3 mackerel, filleted; each fillet cut in half on the oblique

? 4 tablespoons flour

? Extra virgin olive oil

? 3 large mild onions, peeled and thinly sliced

? 125 ml elderflower or raspberry vinegar

? 75 ml dry white wine

? 3 bay leaves

? 3 or 4 heads of elderflowers

? Seasoning to taste – sea salt, freshly ground black pepper and sugar

? 3 or 4 tablespoons pine nuts – lightly toasted

? 3 or 4 tablespoons raisins – soaked in white wine for a few hours

Dip the fish fillets in flour, shaking off the excess, and fry them gently in a little oil until just cooked. Remove with a slotted spoon and drain on paper towels. Discard the oil and wipe out the frying pan. In some fresh oil, gently fry the onions until completely soft, but not browned or caramelised in any way, as this is a pale dish. Add the vinegar, wine, bay leaves, elderflowers and bring the boil. Add seasoning as you think fit, bearing in mind that this is a sweet and sour dish, then add the pine nuts and raisins. Put a layer of onion mixture in a glass or other non-porous dish, then a layer of mackerel, more onions and so on until you have used up the ingredients, making sure you have onions on top. Cover with cling film, refrigerate and allow a couple of days for the flavour to develop. These will keep for a week in the pickle. Allow to come to room temperature before serving.

Cook’s note: other oily fish can be used in this recipe; salmon works well.