KO EN Japanese Side dish⏱ 90 minEdit history

Umeboshi (Salted and Sun-Dried Ume Plums)

Name: Umeboshi (Salted and Sun-Dried Ume Plums)
Prep time: 1 h 30 min
Total time: 1 h 30 min
Yield: 20 servings
Cuisine: Japanese
Ingredients: 1 kg ume plums; 200 g coarse salt; 50 ml shochu; 200 g red shiso leaves; 40 g salt

The Japanese cure in which ume plums spend a month under salt, three days in the sun, and then go back into their own liquid. In the dried things around it the drying is the last step — gotgam is finished by it, danmuji is dried so a bran bed can work unsubmerged, bugak so it can be fried, lavash is dried and then revived with water, hwangtae is freeze-dried into a sponge, qurut is dried to a stone. Umeboshi is the one where the drying sits in the middle, and where the fruit returns afterwards to the brine it made.

Ingredients

20servings

Umeboshi (1kg of plums)
ume plums · ripened to yellow; see the tips1 kg
coarse salt · 20% of the weight of the fruit200 g
shochu · 35% ABV, for wiping the fruit and the crock50 ml
To colour it red (optional)
red shiso leaves · leaves only, stems removed200 g
salt · 20% of the weight of the shiso40 g

Steps

Soak the plums overnight to draw off the harshness, then pick the stem scars out with a cocktail stick. Discard anything bruised or soft — one bad plum puts the whole crock at risk.
Wipe each plum dry with a cloth, then again with a cloth dampened in shochu. Water left on them is where mould starts.
⏲ 30 min
Layer the plums and salt into a sterilised crock, alternating, and finish with a layer of salt. 20% of the weight of the fruit is the traditional figure.
⏲ 20 min
Weigh them down with as much again in weight, cover, and leave somewhere cool. Within three or four days the liquid rises above the fruit — that is umezu, plum vinegar. If nothing has risen after three days, there is not enough salt.
Leave it a month. Nothing is ripening here: the salt is pulling water out, and the plums’ own citric acid is concentrating in that water.
If you are using shiso: knead the leaves with salt twice, wringing out the black liquid each time, then a third time with a little umezu poured over. The leaves turn from purple to bright red at this point. Lay the shiso over the plums and put it back.
⏲ 20 min
Pick three good days of midsummer sun. Lift the plums out and spread them on trays without touching, in the sun by day and out in the night dew, turning them once a day. This is doyoboshi.
On the evening of the third day, put them back into the umezu. That the drying is the middle rather than the end is the whole of this pickle. Leave them overnight, then lift them into a storage jar.
Age them somewhere cool and dark for three months or more. The salt rounds off with time. Bottle the umezu separately and use it to dress vegetables and to season sushi rice.

Tips & Variations

Variations

Shirobōshi (白干し): made without shiso. ko.wikipedia gives it as around 20% salt and notes it keeps exceptionally well. The red colour is an Edo-period addition, from the shiso.
Umezuke (梅漬け): salted but never sun-dried — this recipe with the middle step taken out, which is why it has a different name.
Seasoned umeboshi: the low-salt jars in the shops are shirobōshi soaked to draw the salt back out and then re-seasoned. As the same article says, they keep far less well and carry a short date. Made traditionally and stored properly, a hundred-year-old one is still edible.
Neriume: stoned and worked into a smooth paste, for dressing cucumber or chicken breast.
Umezu: not a by-product but a seasoning. Red if shiso went in, white for shirobōshi.
Where it turns up: onigiri and lunchboxes. A box of white rice with a single umeboshi in the middle is called a hinomaru bento, after the Japanese flag.

Tips

The drying is the middle, not the end. In the dried things around it the drying finishes them: gotgam is the drying, takuan is dried to bring its water activity down far enough for a bran bed to work unsubmerged, bugak is dried so it will puff in oil, lavash is dried hard and then revived with water, hwangtaeguk's pollock is frozen and thawed until it is a sponge, and the qurut in qurutob is dried until it is as hard as a stone. Umeboshi takes three days of sun and then goes back into its own liquid. The skin toughens and the flesh softens again, and it ends up neither dried nor wet.
It is not a ferment. Fermentation basics's first lever tops out at "5%+ for long storage" and this is 20%, with the plum's own citric acid on top of it. Nothing lactic can grow and neither can mould. Unlike kimchi or paocai, this is a pickle in which nothing grows at all — which is why it lasts a century.
Read it beside pikliz. In both, the liquid is a product in its own right. But pikliz pours its acid out of a bottle, and umeboshi takes water away until the acid the fruit already had is concentrated. Opposite routes to the same place.
The shiso red is a pH indicator. Shiso's anthocyanin is bright red in acid, which is why the leaves look dark purple while you are kneading them and turn red the moment umezu goes on. That is not what happens in borscht: there the acid protects betanin's colour, and here the acid changes the colour.
Do not cut the salt. Below about 15% the risk of mould rises sharply. If it is too salty for you, the order is to make it properly and desalt it afterwards — which is exactly what the supermarket jars do.
The liquid has to rise within three days. If it does not, there is too little salt or the fruit was too unripe. Anything sitting above the liquid moulds first, the same rule paocai lives by.
The three days of sun need not be consecutive. If it rains, bring them in, put them back in the umezu, and go out again on the next clear day. Doyoboshi names the sun of high summer.
White crystals on the surface are salt, not mould. As the article notes, in dry conditions the salt crystallises out at a few millimetres across. Fuzz is mould; crystals are not.