Carefully wash the apricots and dry well with a paper towel. Remove the stem with a toothpick.
Wipe the apricots from Step 2 with a vodka-soaked paper towel. (This is to prevent mold from forming)
Add Steps 1 and 3 alternatively to a sterilized bottle. (Sterilize the bottle by boiling and wiping with vodka.) Store as-is for a month in your pantry.
During storage water will form so shake the bottle about one a day to spread the liquid. The picture shows two days after making. The volume has decreased.
When they are well-pickled, put them outside to dry them out. On the first day they will be prone to sticking to the net so turn them over soon.
If you put the pickled apricots back into Step 5's bottle on the first evening after leaving them out, they will become soft, but if they have already softened you don't have to worry. You can take them inside.
They will be done on the 2nd or 3rd day of drying out. Try not to get them wet with rain or other moisture. The picture of the basket in Step 6 or 9's bottle is fine. The salt will spread gradually.
I promptly used some in an onigiri rice ball. The color was slightly yellow but the flavor was like a tart, salty umeboshi pickled plum. They turned out well and mold-free.
If you have red shiso, prime them by rubbing with salt to remove bitterness and add them to Step 5 when the liquid starts to form. The shiso-addition gave me a good result.
Story Behind this Recipe
Japanese ingredients are hard to find when living overseas. Even if they are available they are usually expensive or not from Japan etc. When I saw apricots that resembled ume plums I wondered if I could make make something myself to be similar to pickled plums. I researched and fine-tuned to come up with this.
The first apricots of November work well. I used ripe apricots that I was given and they got too mushy.
Citric acid can be found alongside the baking powder in supermarkets. I used salt from Hakata Prefecture.