The Quiet Science of Temperature Control in Men-Eiji's 18-Hour Simmer

In Sapporo, where winter settles over the city like a heavy wool blanket, the kitchens at Men-Eiji keep watch over enormous steel pots that bubble steadily through the night. The broth at the heart of every bowl — a rich gyokai-tonkotsu made from seafood and pork bones — owes its depth to an unhurried simmer that runs for eighteen hours.

Founder Jun Furukawa built his reputation on this patience. After years of training in Tokyo and collaborations that carried him to kitchens from New York to Hanoi, he returned to his hometown with a single obsession: controlling the temperature at which bones surrender their flavour. Every visitor who steps into Men-Eiji Hiragishi BASE or Duck Ramen EIJI eventually tastes the result of that obsession.

For Australian diners, this kind of slow, almost meditative broth-making resonates with our growing appetite for craft food. In Sydney's CBD and Melbourne's inner north, queues form outside ramen counters before the lunch rush, and bowls priced north of twenty dollars are no longer unusual. Australia imports more instant ramen per capita than almost anywhere in the Western world, and the appetite for the real thing has only intensified since the pandemic shifted eating habits toward takeaway comfort food.

Yet the difference between a forgettable bowl and a memorable one often comes down to something most diners never see. Temperature — held carefully across a long simmer — is the silent partner in every spoonful. Understanding how Men-Eiji manages that heat reveals why the broth tastes the way it does.

The Foundation of Gyokai-Tonkotsu

Gyokai-tonkotsu begins with two distinct stocks that eventually merge into a single, cloudy, aromatic whole. The gyokai side draws on niboshi (dried sardines), katsuobushi shavings, and occasionally kombu, while the tonkotsu side demands hours of attention to pork bones, marrow, and connective tissue. At Men-Eiji, these streams run in parallel for much of the day before being married together in the final hours.

Bones contain collagen, fat, and minerals locked inside rigid structures. Heat unwinds them. Water at a rolling boil churns the pot and emulsifies the fat too quickly, producing a greasy, opaque liquid that tastes rough. Water held just below a true boil releases those same compounds gradually, allowing the broth to clarify while gaining body. The difference is the line between a broth that coats the tongue and one that scatters.

The broth also depends on a careful ratio between the two streams. Too much gyokai and the result reads briny, almost fish-sauce forward. Too much tonkotsu and the seafood notes vanish under the weight of the pork. Skilled cooks taste throughout the cook, adjusting the blend as the simmer progresses and the flavours settle into their final balance.

Why Eighteen Hours Becomes the Magic Number

The eighteen-hour figure often surprises first-time visitors to the kitchen. It is not an arbitrary number, and it cannot be compressed without altering the chemistry. Collagen converts to gelatin somewhere between seventy and eighty-five degrees Celsius, and the conversion accelerates as the simmer continues. By the tenth hour, most of the available collagen has already given way; the remaining eight hours deepen the body and pull additional mineral notes from the bones.

Shorter cooks tend to produce a broth that tastes thin even when it looks cloudy. Longer cooks risk the opposite problem: muddy flavours, scorched aromatics, and a greasy mouthfeel that no amount of skimming can rescue. The window between these two failure points is narrower than most recipes suggest, and it shifts depending on the cut of bone, the freshness of the seafood, and the specific heat source used in the kitchen.

Jun Furukawa has described the eighteen-hour mark as the point where the broth stops transforming and starts holding steady. The aromatics have reached their peak, the proteins have fully suspended, and the broth is ready to receive the tare, the oil, and the final toppings that turn stock into a finished bowl of ramen. Pushing past that point adds little and costs flavour.

The Hidden Variable Most Recipes Ignore

Most home cooks who attempt a long-simmer broth focus on time. They set the pot on low and leave for the day, hoping patience alone will do the work. Men-Eiji treats temperature as the actual ingredient. Jun Furukawa and his team log readings throughout the cook, adjusting gas burners and induction plates to keep the liquid hovering in a narrow band — high enough to keep collagen converting, low enough to avoid the aggressive agitation that destroys clarity.

This kind of monitoring echoes what chefs in the Brunswick restaurants of Melbourne have long practised with slow-braised lamb shanks and bone broths: long cooks succeed when they are measured cooks. The Australian Institute of Food Science and Technology has noted that consumer demand for transparent cooking methods has grown alongside the popularity of food documentaries, and diners now ask servers how long a broth has simmered with the same curiosity once reserved for wine lists.

Temperature also affects which aromatic compounds rise to the surface and which remain suspended. Volatile oils from pork fat behave differently at ninety-five degrees than they do at a hard, rolling boil. Seafood elements, which are added later in the Men-Eiji process to preserve their delicate notes, can turn acrid if subjected to the heat of the pork side for too long. Managing this thermal choreography is closer to conducting an orchestra than to following a recipe.

Equipment Choices in a Sapporo Kitchen

The tools matter as much as the technique. Men-Eiji uses heavy-gauge stainless pots that distribute heat evenly and resist the hot spots that plague thinner cookware. Gas burners with wide flame patterns allow the cooks to make fine adjustments, and a series of thermometers — both clip-on probes and infrared units — give readings at multiple depths within the pot.

A commercial kitchen in Sydney or Brisbane would face similar equipment considerations, and the parallels are worth noting. Australian food safety regulations, administered through Food Standards Australia New Zealand (FSANZ) Standard 3.2.2, require that hot foods held for service stay above sixty degrees Celsius. A broth that simmers for eighteen hours must therefore be managed not just for flavour but for compliance, with documented temperature logs that any environmental health officer can review during a routine inspection.

Jun Furukawa has spoken about how these disciplines shaped his approach after international stints, including projects that connected him with kitchens in Southeast Asia. A recent profile on the 81-plus.com platform traces his path from those collaborations to the current Sapporo operations, underlining how a single-minded focus on the simmer became his signature.

The Australian Connection to Sapporo-Style Broths

Sapporo-style ramen carries a particular weight in Australia. The city's miso-based heritage crossed the Pacific decades ago and now shapes menus in food courts from Chatswood to Box Hill. Sydney alone is home to several dedicated Sapporo-style counters, and Melbourne's ramen map includes at least a dozen venues that lean heavily on the rich, fatty profiles that originated in Hokkaido.

Australian diners have grown comfortable with these heavier bowls, partly because they pair well with the local preference for substantial meals and partly because of the multicultural fabric of our biggest cities. The shared meals culture in Adelaide's Central Market, the late-night ramen counters of Melbourne's Russell Street, the weekend queues in Sydney's Haymarket — these are all part of a wider acceptance of broth-driven cooking as everyday food rather than occasional indulgence.

For chefs inspired by Men-Eiji, the lesson is that broth cannot be faked. A shortcut stock, however cleverly seasoned, cannot replicate the body that eighteen hours of controlled heat produces. Even the most ambitious Australian ramen makers begin their day before dawn, building the simmer from scratch and treating the pot as the foundation of everything that follows. Reading how other kitchens approach cross-cultural sauce work — such as a recent sauce fusion exploration in Ho Chi Minh City — reminds us how widely this patient, layered cooking now travels.

What Home Cooks Can Steal from the Simmer

Few home kitchens can replicate the eighteen-hour commitment, but the underlying principles travel well. A probe thermometer, even an inexpensive one, transforms a long simmer from guesswork into a controlled process. Watching the pot settle into a band between eighty-five and ninety-three degrees Celsius — barely trembling rather than breaking into large bubbles — gives a cook a window into what professionals monitor all day.

Skimming at the right moment matters too. Men-Eiji's cooks remove impurities during the early hours, when the temperature is climbing and the proteins are coagulating at the surface. Leaving that layer in place past a certain point allows it to break down and reincorporate, dulling the flavour. A large flat spoon or a fine mesh skimmer, used patiently, does the work that hours of additional simmering cannot undo.

Finally, the seafood elements should join late. Even a modest quantity of dried sardines or a strip of kombu, added in the final forty-five minutes of an otherwise long cook, lifts the broth into something more aromatic and more reflective of the gyokai tradition that defines Men-Eiji. The pork side provides body; the seafood side provides lift. Heat is the lever that balances them.

If the science of a patient simmer has sharpened your curiosity, the next step is the most rewarding one: tasting the result in person. Visit Men-Eiji Hiragishi BASE or Duck Ramen EIJI in Sapporo, browse the menu and opening hours on the official site, and follow Jun Furukawa's international pop-up calendar for a chance to try the broth closer to home in Australia. Book a table, gather friends who appreciate the long way around, and experience how eighteen hours of careful heat become a single, unforgettable bowl.