It has been raining since morning but the air feels hot and balmy at Jamu Bukti Mentjos, a jamu parlour in Indonesia’s capital Jakarta. Despite a recent surge in coronavirus cases in Indonesia, customers sit almost shoulder to shoulder at the parlour, which occupies the front part of a house on Salemba Tengah street. Standing behind them are food-delivery drivers, waving their phones and scraps of paper containing orders. The handful of staff manning the bar look rather overwhelmed. Two waitresses behind the bar are scooping brown powder from an assortment of glass jars on racks lining the walls, putting it into clear coffee mugs and pouring steaming hot water into them. A heady aroma of turmeric and galangal wafts in the air. For centuries, Indonesian people have believed jamu prevents and cures ailments ranging from premenstrual syndrome to tumours and cancers. With coronavirus cases in the country becoming more widespread , people have been returning to these long-established concoctions in the hope of improving their immunity. On March 23, Indonesian President Joko Widodo said to the press that a lockdown was still not option for the country. Since then, Indonesia has seen its biggest daily spike in new coronavirus cases, which now number over 700. This afternoon, despite having to wait more than 20 minutes for their jamu to be served, customers sit without a fuss in the stuffy room. “I always come here whenever I’m feeling unwell,” says Ambar, 45, a housewife and long-time customer sitting on a table next to me. “So far, their jamu works. Besides, the president also drinks it daily to keep the coronavirus at bay.” (Widodo admitted he drank jamu three times a day to prevent getting infected by the coronavirus in his opening speech at the second Asian Agriculture & Food Forum in Jakarta on March 12.) After drinking her fill, Ambar leaves with four medium-sized bottles of the concoction. “They’re for my husband and youngest son,” she says. “They’ve been feeling feverish and had dry coughs for two days.” A young couple wearing surgical masks take Ambar’s table after she leaves. They talk and joke as they peruse the parlour’s menu. “We’ve never seen such an increase of customers before,” says Horatius Romuli, the parlour’s owner. “The increase is about 50 per cent since early March. Most of the new faces are young people, teenagers and even children coming in with their parents.” Romuli’s grandma started the parlour in Solo, a city in Central Java province, in the 1940s. “She experimented with different herbs and roots to make health drinks for herself and family members,” the 61-year-old proprietor says. “Then our next-door neighbours started asking her to make something for their sick children. She did and they were healed.” The efficacy of her concoctions spread through word of mouth. “People were saying that grandma’s jamu is ‘terbukti’ [proven], hence the [parlour’s] name Jamu Bukti,” Romuli explains. Our ancestors knew what’s best. Their recipes are proven effective against any illnesses, even until now Wagirah, a jamu pedlar in south Jakarta Horatius also believes that Covid-19 – the disease caused by the novel coronavirus – can be prevented by drinking jamu. “Those who have been drinking jamu have no fear of the virus, because the main ingredients of jamu – turmeric and ginger – are known to have preventive qualities against coronavirus,” he says, beaming confidently. Romuli drinks jamu sambiloto, which includes the bark and leaves of the sambiloto, or green chierta, plant. The bitter drink is believed to boost the immune system, alleviate cold and fevers, and prevent cancer. “If our immune system is strong, we will not catch any [viruses],” he says. “People may cough and sneeze in front of and behind us, but we will not get infected.” Suwe Ora Jamu, a jamu parlour in Petogogan, south Jakarta, is more quiet when I visit. A waiter opens the door and asks me to first wash my hands at the sink outside before entering. Two tables are occupied in the smoking room, while a man in the non-smoking area is sampling the parlour’s Sapta Sari, a selection of seven basic jamu served in shot glasses. As I browse the menu, two delivery drivers show up and give the waiter long order lists. “We’ve been having more takeaway orders since the coronavirus was detected in Indonesia [in early March],” says Nova Dewi, the parlour’s owner, adding that her customers have increased by about 65 per cent since the outbreak. “Drinking jamu is one of the preventions against Covid-19,” she says. “But in addition to that, we should also obey the government’s wish for us to stay at home and maintain our hygiene.” Wagirah, a jamu pedlar on Ampera Street, south Jakarta, says her profits have tripled since the coronavirus was first detected in Indonesia. “I usually took home around 50,000 rupiah [US$3] a day, but these days I can take home up to Rp150,000,” she says. The 60-year-old carries around 12 bottles of jamu concoctions in her pushcart. The bestselling one these days is jamu cabe puyang, which is made of turmeric, Javanese long pepper, fennel seeds and bitter ginger. The bitter and spicy drink breaks fever, heals coughs and clears the lungs, she says. “Our ancestors knew what’s best. Their recipes are proven effective against any illnesses, even until now,” she says. Evie, a journalist who lives nearby, is a loyal customer of Wagirah’s. “I used to drink jamu whenever I got a chance,” Evie says. “But now, I drink it almost every day, because I know that [infection by] the coronavirus can be prevented if our body is strong and healthy. And jamu is a way to achieve it.” But can jamu really prevent Covid-19? “Directly, no,” says Dr Jerry Eddya Poetra Boer, an internist at Agung Hospital in central Jakarta. “But … if we have a good immune system, we will not get infected by it.” Jamu, according to the internist, has qualities that improve our immune system , but “you have to ensure that the jamu you drink is fresh and unadulterated with chemicals,” he says. Dr Zubairi Djoerban, a haematologist-oncologist at the Kramat 128 Hospital in central Jakarta, warns against spreading false rumours about jamu’s healing powers. “Jamu cannot prevent us from getting infected from the coronavirus. Neither can it heal us after getting infected,” he says. “Even if you’re strong and healthy, you can still get infected. Take the footballers [like Paulo Dybala and Paolo Maldini] for example. They’re very fit and healthy, but they still got infected by the virus.” However, if we are fit and healthy, coronavirus symptoms are likely to be milder, he adds. The best preventive step is to stay at home. Wear a mask if you absolutely must go out – and maintain good hygiene. Purchase the China AI Report 2020 brought to you by SCMP Research and enjoy a 20% discount (original price US$400). This 60-page all new intelligence report gives you first-hand insights and analysis into the latest industry developments and intelligence about China AI. 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