A plate that includes umeboshi (lower right) from Oakland’s Yumé Boshi. Credit: Shirley Huey

The taste: Salty, like plunging your tongue into the ocean. Then mouth-puckeringly sour. The tart and savory flavors lead to a fleeting aftertaste of fruit, just a hint of sweetness, a plummy perfume on the tongue. This is the experience of eating umeboshi, the salt-pickled Japanese ume fruit. Commonly referred to as a plum, ume comes from the Prunus mume tree, which is actually in the apricot family.  

A meal and pantry staple in Japan, umeboshi is often eaten with a bowl of rice or in an onigiri rice ball. Umeboshi is eaten for its taste as well as for health benefits; it is considered by many in Japan as a cure for hangovers, indigestion and morning sickness. 

Typically, these small plums are harvested and brined to ferment in the late spring to early summer. In the East Bay and Northern California, we are lucky to have umeboshi made locally and with love by several pickle and fermentation experts. This ingredient, which is seeing increased popularity, taps into the flavors of traditional everyday Japanese home cooking and also reflects a California approach, with California-based makers and California-grown ingredients. Access to the fruit is likely to get more difficult in a time of drought, staffing, and transport issues as well as the consolidation/sale of farms and an increased demand for ume for different uses. 

Berkeley resident and personal chef Ayako Iino has been making umeboshi the traditional way since she was a child. “Umeboshi making is very common in a lot of families in Japan,” Iino said. “My mom used to make it every year. She had a tree in her garden. That is very common traditionally. Later when I moved to a more rural area in Japan, I also got ume from the farmers around me and learned from the locals who made it.” Like many food cultural traditions, she said every family made theirs a little bit different from the next. 

A jar of umeboshi from Yumé Boshi. Credit: Shirley Huey

At her company, Yumé Boshi, Iino has been producing what a friend of mine (who grew up in Japan eating the condiment every day and, full disclosure, is a former employee of the company) says is the best she’s ever had. 

Iino also has a background in macrobiotic cooking. She brings deep knowledge from growing up making pickles with her mother in Nagoya, Japan as well as later living in a rural village and learning from grandmothers how to make traditional preserved ume. Iino has taken great pains to develop strong relationships with her farmer producer in Oroville in order to ensure that she can access the right ume fruit, harvested at the perfect time, she said.

With stints at Chez Panisse, Oliveto, and Boulette’s Larder, Iino brings her cooking know-how to make award-winning ume products, including fruit syrups, jams, vinegars, and of course, the signature umeboshi. Due to the increasing popularity of ume products and the difficulty of finding more supply of the fruit, Iino has embraced a low to no waste approach to the valuable ume. She recently rolled out a line of new products including shrubs, furikake using ground ume, and crackers with umeboshi plum baked in. 

Ume plums in the pickling vat, where they’re layered with salt and weighted down. Credit: Shirley Huey

At Berkeley’s Cultured Pickle Shop, Alex Hozven and Kevin Farley have been fermenting and pickling for over 25 years and making umeboshi since 2007, starting the project after a Berkeley customer brought them ume plums from her backyard. Now the shop sources its plums from orchards in Winters and in Southern California, and makes umeboshi at the shop along with a host of cultured and fermented products, including kombucha, pickles, kimchi and sauerkrauts.

Umeboshi, or its byproduct ume vinegar, is often featured as part of Cultured Pickle’s weekend Rice and Pickles three course meals, lauded by local food lovers and food media for inventively flavorful combinations and the care taken with these ingredients. Since the pandemic, the bowls are also available for takeout. A recent weekend’s menu included thinly shaved onion soaked in ume vinegar. 

Hozven recently walked me through her process for making umeboshi, which starts with ume plums harvested at just the right time. She buys her ume plums straight from the orchard because “the ones you see available wholesale … usually they’re just picked so green so that they’ll travel and keep well, but when they’re that green they’re too rock hard to make good umeboshi.” 

Next, the plums go into a pickling vat, layered with salt and weighted down. “You need a lot of weight to get a brine out of an unripe fruit. When they first come to us, we’ll sort them, we’ll take the little stems out, and then we’ll salt. They soak overnight, and then the next morning, they’re salted at 10% salt. Then they’ll kind of sweat for the day. At the end of the day, they’ll go into this tank.” 

Where to find locally made umeboshi

The Cultured Pickle Shop
800 Bancroft Way, Suite 105 (at Fifth Street), Berkeley
The 2021 batch of whole plums is sold out, but watch for the 2022 batch in December. Paste from some of the fruit will be available later in the summer. 

Yumé Boshi
Sold online or and by stockists including Berkeley Bowl, Monterey Market, Oaktown Spice Shop, Market Hall Foods and many others.

The plums in the photo above are “almost four weeks in,” Hozven said. “When they come to us, they’re green and ideally starting to blush. The blush is kind of an indication that they have the plummyness and the moisture within them that you’ll be able to coax a brine out of them.”

It’s a balancing act, literally, to ensure the plums ferment instead of getting moldy and rotten. “The first couple days,” Hozven said, “this entire tank had buckets of rocks on it … a lot of weight … as much weight as you can get on it.” That’s because “a lot of the potential problems you can get from umeboshi [are] not getting enough juice to create an anaerobic environment pretty quickly, and then you’ll just get a lot of mold issues.” 

Within about two days, enough juice should be extracted from the plums that they can leave “a tiny bit of weight to keep that stable as it is.” Then it becomes a waiting game. “After about four weeks, they’ll develop an acid. They’ll turn kind of yellow,” and the batch will be removed to dry.

Ume on the drying rack. Credit: Shirley Huey

In Japan, at this point in the process, the plums would be dried on bamboo mats in the sun. “We don’t really have that kind of a climate,” Hozven said of the East Bay. Here, the plums are dried on trays for about a week. While the ume are drying, the liquid that they were sitting in is infused with red shiso leaves, which provides flavor and color to the finished product. 

“The red shiso when it first comes to us looks much more purple,” Hozven said. “It goes through a process of squeezing so you get more of the blue-purple pigments out. And then it gets put into this brine which already has an acid developed, and it turns into a deep ruby red like this,” Hozven said, pointing to a plastic container holding a deep burgundy colored liquid. 

The brine from the plum vat is infused with red shiso leaves, hence its brilliant color. Credit: Shirley Huey

After a few days, the drying plums and the brine are returned to a tank, where they will sit together for about six more months. How long you want to age them after that is a personal decision, Hozven said. “We will age them for a minimum of about 6 months, and at that point, they are preserved enough that they can sit out forever and be completely preserved.”

The plums will get more and more concentrated in flavor over time after that, Hozven said. Personally though, Hozven said she prefers when they’re a little younger, when they’re ”a little more succulent and a little more plummy.”