Step by step
At Noma, we prefer white asparagus for its delicate flavour, but green asparagus ferments well, too. This method will make 500gm of lactofermented white asparagus.
The amount of salt and water needed will depend on the size of the fermenting vessel. For 500gm asparagus, a 2-litre mason jar should be a good size. In order to determine the required amount of salt and water, first place the jar on a scale and tare it (meaning adjust the readout to zero to discount the weight of the container). Stand 500gm white asparagus spears upright in the jar (trim if necessary) – they should be packed relatively tightly but not so tight that you bruise the asparagus. Pour in enough water to cover the asparagus, and take note of the total weight of the water and the asparagus. 2
Calculate 3 per cent of that weight, and add that much non-iodised salt to a large bowl. Pour the water out of the jar into the bowl. Whisk together the salt and water until the salt has dissolved. Slice half a lemon into 5mm-slices. Pour brine into the jar over the asparagus and distribute the lemon on top. Keep the asparagus spears submerged beneath the level of the brine by weighting them down with a water-filled zip-lock plastic bag, a fermentation weight, or some other clean object wedged beneath the neck of the jar. Cover the jar with a lid, but don’t seal it so tightly that gas can’t escape.
Ferment the asparagus spears in a warm place (about 21°C) for 2 weeks. Begin checking after a couple of days (above, day 4). If you taste lightly sour notes – beyond the lemon – you’re on the right track. 4
The finished product will have crunch, balanced bitterness and umami (above, day 7). Once the asparagus has pickled to your liking, leave it in the brine, seal the container, and transfer to the refrigerator. It will keep for several months. Serve as an accompaniment to charcuterie, or use as a crunchy addition to salads.
The new gherkins We like to deploy lacto-fermented asparagus spears the same way you would gherkins, as refreshing palate cleansers or tart garnishes. Serve them simply doused in a bit of olive oil as a side, whether you’re having lasagne or grilled ribs. Or, the next time you’re making burgers, thinly slice a spear of lacto-fermented asparagus and shingle the slices on one side of the cooked patty, then continue with your usual condiments. You’ll be counting down the days until white asparagus comes into season again.