Are the black bits in Hokkien mee safe to eat? Hawkers and experts weigh in

SINGAPORE – Of late, the tiny black specks clinging to pale strands of Hokkien mee have sparked lively debate online.

In a post on the Hokkien Mee Hunting group on April 13, Facebook user Curtis Khor charged that some Hokkien mee stalls do not brush and clean their woks, resulting in the charred black bits.

The post drew 132 comments from Hokkien mee lovers here, with diners divided on the issue. Some shrugged and ate on, while others said they will not return to stalls serving noodles with the black specks.

What are these black bits? Harmless char from high-heat frying, signs of a dirty wok or something diners should be concerned about?

The Straits Times posed this question to hawkers, a culinary consultant and medical experts. Here is what they said.

What hawkers say

Four Hokkien mee hawkers interviewed say the specks are not metal scrapings from the wok, but burnt food residue from high-heat frying.

Madam Lucy Chng, 65, who helps her husband, Mr Ong Cheng Hoe, 70, at Hoe Hokkien Mee at North Bridge Road Market & Food Centre, says he prefers to fry up Hokkien mee with as few black bits as possible.

The couple have served a wet style of Hokkien mee – cooked with prawn stock, pork belly, sotong and prawns – since 2016.

The wok is washed after every batch of about four plates, she says, though black bits still appear when garlic burns over high heat.

“We want to present customers with a version of Hokkien mee that we enjoy eating ourselves,” she says.

“When a plate is full of black bits, it is a sign that the wok is not cleaned.”

At Ah Jie Hokkien Mee in Ang Mo Kio, co-owner Teo Jun Jie, 28, says the black bits in his wet-style Hokkien mee are charred particles of noodles, egg and garlic.

The stall uses a cast-iron wok, which is washed with water and brushed with a bamboo brush after every batch of 10 to 12 plates.

“When frying the noodles before we add the stock, there are parts that get charred, because we are using the highest heat level of our commercial gas burner,” he says.

The char forms a crust on the noodles and eggs, which chips off during stir-frying as black bits. Mr Teo deliberately chars the noodles slightly for a smokier flavour.

“I cannot lower the heat because it will change the cooking time of the noodles and the noodles will get too soggy if we cook them over heat for too long,” he says.

“The black bits are not wok hei,” he maintains. “Wok hei refers to the smoky aroma of the wok.”

The charred particles can create a smoky aftertaste, which some diners may mistake for wok hei, he adds. But bitterness is not acceptable.

When Mr Teo first switched to a more powerful gas burner, the heat was hard to control. The noodles looked fine, but tasted bitter, a sign they had been burned. Customers who complained got a new batch.

“To the naked eye, you can’t tell it is burnt,” he says. “The bee hoon is still white, but there will be a bitter, charred taste.”

At Shiok Hokkien Mee, owner Mitchell Ong, 27, says his chain has received fewer than 10 complaints about black bits since it started operating at Golden Mile Food Centre in 2023. It now has eight outlets islandwide.

“Customers have their own preferences. I do not feel annoyed that the black bits have become a topic of discussion online,” he says.

“Conversations like that show Singaporeans care very deeply about their food. For customers who are not in the food business, they do not know the exact cooking process and may find it difficult to understand and accept.”

He says the black bits may come from finely minced garlic or egg cooked over high heat.

“If the garlic is too fine, it burns,” says Mr Ong, whose Hokkien mee sits between wet and dry, which he describes as similar to carbonara but with some gravy.

“I expect the black bits when I eat dishes like Hokkien mee and char kway teow,” he says.

He believes Hokkien mee has a visual disadvantage as a dish.

“There is no way to camouflage the black bits, unlike char kway teow, where it is harder to see burnt bits because of the dark sauce.”

He notes that the black bits are more visible when stallholders use lighter-coloured plates. His stalls use white plates for small orders of $5, and black plates for orders of $8 and above.

Mr Kelvin Teo, 38, who runs The Neighbourwok, which has three outlets in Bukit Batok, Owen Road and Clementi, agrees that the black specks are tiny food particles such as garlic, sauce, egg or noodles that get browned during high-heat wok frying.

The brand serves a wetter style of Hokkien mee, with a slightly sticky gravy.

“Wok hei refers to the smoky aroma and flavour created from cooking over intense heat,” he says. “The black specks are a by-product of the wok-hei cooking process.”

What the culinary consultant says

But culinary consultant Benny Se Teo, 66, offers a different view.

Mr Se Teo, who conducted a private Hokkien mee masterclass in 2025, says there is a Cantonese term for the black residue from the wok: It is wok see, referring to wok filth.

He believes the black bits may be carbon residue from the wok and, possibly, tiny particles from the wok surface if the wok is not cleaned thoroughly between batches. Burnt food residue may also contribute.

“Black bits are avoidable if the person who fries is conscientious and washes the wok after every batch of noodles cooked,” he says. “It is a test of the cook’s patience.”

He points to restaurant kitchens, where woks are repeatedly scrubbed with running water between dishes.

“For some dishes, the chefs have to scrub the wok as part of the process for cooking one single dish, because of the different cooking styles involved.”

But he acknowledges that hawkers work differently.

“For a hawker, when you fry Hokkien mee, those queueing up are watching you. People do not like waiting and you have to work fast,” he says. It may not be possible to wash the wok between batches or thoroughly enough to keep black bits at bay.

What other experts say

Medical and food science experts interviewed by ST say the black specks found in wok-fried foods are charred food residue.

Dr Gloria Chan, 40, consultant at the Department of Haematology-Oncology at the National University Cancer Institute, Singapore, says the black particles seen in wok-fried foods are typically charred food residue formed during high-heat cooking.

These arise when oils, proteins and carbohydrates are exposed to very high temperatures, leading to burning and carbonisation.

Charred foods can contain compounds such as polycyclic aromatic hydrocarbons and heterocyclic amines, she says. These chemicals are carcinogenic in high doses, as shown in studies done on animals.

But she adds that there is no definitive clinical evidence that trace amounts in a plate of Hokkien mee significantly increase cancer risk in humans.

“In practice, cancer risk is influenced by long-term dietary patterns and cumulative exposure, rather than a single meal or occasional intake,” she says.

She recommends moderation rather than avoidance, and says those who are concerned can avoid heavily charred portions.

“For most people, occasional consumption – for example, once every week or two – is unlikely to pose significant risk,” she says.

Mr Louis Yap Wei Ming, 37, senior dietitian at Mount Elizabeth Novena Hospital, does not think the black specks are wok fragments or metal contamination.

“While there were historical beliefs, dating back many decades, that intense heat could chip parts of older, poorly made woks, modern carbon-steel woks and current cooking practices make this very unlikely.

“In hawker cooking today, these dark fragments are overwhelmingly burnt organic material, not metal contamination.”

His practical advice is to remove visibly burnt or heavily charred bits, especially from protein components, and eat vegetables on the side.

He adds: “Let’s not give Hokkien mee a bad name. Many beloved local dishes – such as char kway teow, fried rice, stir-fried hor fun and various zi char dishes – may contain some charred bits as part of high-heat cooking.

“These flavours are part of what makes Singapore food distinctive and enjoyable. I generally eat these dishes as they are, but if I notice parts that are significantly burnt, I simply remove them.”

Dr Heng Kiang Soon, 50, specialist in food innovation at Republic Polytechnic’s School of Applied Science, says the black bits can form in two related ways.

During high-heat cooking, residue from meat, seafood, noodles or sauces sticks to the wok and, when repeatedly exposed to intense heat, dry out, degrade and char.

Food can also be overheated beyond the optimal stage of the Maillard reaction, the browning process that gives cooked food its colour and savoury aroma.

At higher temperatures, these browned compounds break down through pyrolysis, a process in which substances are changed chemically by high temperatures that leaves behind dark, carbon-rich residues seen as black or charred bits.

“In professional kitchens, it is unlikely that the black bits come from the metal or carbon filings from the wok. Carbon-steel woks are built to withstand very high heat, and any metal abrasion would be obvious and visible,” he says.

For most people, he adds, eating Hokkien mee occasionally, even with some charred bits, is not a major concern.

He recommends: “Practise moderation rather than complete avoidance by rotating food choices and cooking methods and balance the diet with plenty of vegetables and fruit. Vegetable and fruit intake can provide protective antioxidant effects, while fibre-rich foods can help reduce the absorption of harmful compounds in the intestines.”

Dr Heng, who eats Hokkien mee occasionally, adds: “Dishes like Hokkien mee, when enjoyed occasionally and as part of a varied diet, can still fit into a balanced lifestyle and provide energy and nutrients, while allowing people to share experiences over heritage food.”