Perpetual Broth: A Century-Long Simmer

In cultures across the world, 'perpetual broths' were historically brewed for decades straight, building deeply complex flavors. Here's how to adapt it for the modern kitchen.

Otafuku, one of the oldest soup shops in Tokyo, has reputedly been simmering the broth for its oden, a type of brothy stew spiked with soy, since 1945.(HikoPhotography/Shutterstock)

Along a busy street in Bangkok sits an unassuming restaurant that’s been serving the same brothy beef soup for half a century. The family restaurant, Wattana Panich, serves not just the same recipe as it did nearly 50 years ago, but the exact same soup—it’s been simmering in a cauldron at the restaurant’s entrance for generations. After cleaning, the leftover broth is returned to the pan, where it simmers with fresh ingredients, and the cycle continues perpetually.

Wattana Panich isn’t the only restaurant to practice this technique. Otafuku, one of the oldest soup shops in Tokyo, has reputedly been simmering the broth for its oden, a type of brothy stew spiked with soy, since 1945. Chinese restaurants carefully guard their master stocks, some of which have simmered for centuries. Chan Kan Kee Chiu Chow Restaurant in Hong Kong has kept its master stock, which is made with goose and various spices, going for 75 years.

Half a world away, in France, restaurants maintained pots of brothy stews simmering for centuries, refreshed by new ingredients daily. Among them was Paris’s La Marmite Perpétuelle (the Perpetual Pot), which served brothy chicken soups as restoratives from the same pot for over a century before closing around 1820. Another restaurant in the Pyrenees reputedly kept its 15th-century broth simmering until the food shortages caused by the German occupation of World War II forced its closure.

Perpetual broth can be used to make pot-au-feu, a traditional French dish of meat cooked in a broth of herbs and wine. (margouillat photo/Shutterstock)

Filling the Cauldron

Resourceful culinary techniques span the globe. Anywhere hunger and necessity collide, you’ll find ingenious culinary hacks that minimize waste and fill empty bellies affordably.

Before refrigeration existed, keeping food safe from spoilage required constant attention. Salting and fermenting fresh foods helped, but another technique also worked: keeping foods constantly hot. For tavern owners and housekeepers, who already had to keep fires tended lest they go out, keeping a single pot of simmering soup on the fire simply made sense. It took less effort than starting from scratch, and it meant nothing went to waste.

In France, the technique can be used in preparing remouillage and pot-au-feu, a traditional dish of meat cooked in a broth of herbs and wine. For remouillage, spent bones leftover from making broth are reboiled with fresh vegetables and herbs. The remouillage is then added as part of the liquid component of future pots of broth, providing flavor and fortification.

In Italy, you’ll find brodo di carne perpetuo (referred to as perpetual broth or hunter’s stew in English). These immortal broths grow increasingly complex as flavors build, resulting in deeply savory flavors.

Simmering transforms tough cuts of meat, such as pork neck bones and beef knuckle bones, from nearly inedible to something delicious. These cuts tend to be cheap but tricky to use. They contain ample collagen-rich connective tissue, such as cartilage and tendons, which is difficult to eat; however, simmering denatures the collagen and transforms it into gelatin. The resulting gelatin gives the broth its characteristic silky texture and a good dose of protein.

In addition to tough cuts of meat, perpetual stews typically contain spices, herbs, and regional grains and vegetables. Barley and root vegetables were common additions in medieval Europe. The result was a deeply nutritious, affordable meal that was always available to sate the hunger of field workers, family members, and visitors.

Perpetual Broth for the Modern Kitchen

Of course, keeping a pot of perpetual broth in a modern household is more difficult than it was hundreds of years ago. The stove has replaced the hearth, and the slow cooker has replaced the cauldron that hung over the kitchen fire. Few households can dedicate time to constantly tending a simmering pot. Yet the same need exists for families today as it did centuries ago: nutritious, thrifty, easy meals.

With a little effort, home cooks can easily incorporate the principles of this centuries-old technique into their weekly meals. The biggest challenge for home cooks is to make perpetual broth safely. Restaurants that currently use this old technique keep it constantly boiling, and that elevated temperature keeps potential pathogens at bay and prevents spoilage.

In a home kitchen, leaving a pot on the stove that long is both inefficient and potentially dangerous. So the next best thing is to use your slow cooker and save a little of the resulting broth from your weekly pot roast or chicken soup to start the next week’s dish. You can store this starter liquid in the fridge safely for up to five days, or toss it in the freezer for up to six months. Then use it, in combination with water and fresh ingredients, to prepare a future meal. It’s less expensive than using store-bought broths, plus you’ll find that with time, the flavor only gets better.

This slow cooker chicken broth is the next best thing to perpetual broth, perfect for today's home chef. (Jennifer McGruther)

Slow Cooker Chicken Broth

This recipe calls for the leftover bones of a roasted chicken. You can use a chicken that you’ve roasted yourself. If you’re short on time, consider purchasing a rotisserie bird from your corner grocery. You don’t need to peel the onion or the garlic for this recipe; just toss them right into the pot.

Makes about 2 to 3 quarts, depending on the size of your slow cooker

• Leftover bones of 1 roasted chicken
• 1 yellow onion, quartered
• 1 head garlic, smashed
• 1 bunch fresh parsley, chopped
• 2 sprigs fresh thyme
• 1 teaspoon whole black peppercorns
• 1/2 cup dry white wine

Place all the ingredients into the slow cooker, cover with water by 2 inches, and cook on low for 12 hours. Strain, then use as a base for soups and stews.

Store any leftovers in the fridge for up to 5 days or in the freezer for up to 6 months. To use the leftovers for another batch of broth, place all the ingredients into the insert of your slow cooker. Next, pour in any leftover broth that you have on hand, add water to cover the ingredients by 2 inches, and cook as you normally would.

Spent bones left over from making broth are reboiled with fresh vegetables and herbs to make remouillage, which is then added to future broths for flavor and fortification. (Jennifer McGruther)

Remouillage

Remouillage is a light broth made by reboiling bones with fresh vegetables and herbs. Owing to its light flavor, remouillage is best used to fortify other broths or in savory dishes where you might otherwise use water. It can increase the protein content of your broths and lend a deeper and more complex flavor to them.

Makes 2 to 3 quarts, depending on the size of your pot

• Leftover bones from making broth or stock
• 1 yellow onion, quartered
• 2 cloves garlic, smashed
• 4 celery ribs, coarsely chopped
• 2 carrots, coarsely chopped
• 1 bunch fresh parsley, chopped
• 2 sprigs fresh thyme
• 1 teaspoon whole black peppercorns
• 1/2 cup dry white wine

Place all of the ingredients except the wine into a large stock pot. Pour over the wine, and cover with water by 2 inches. Bring to a boil over medium-high heat, then immediately turn the heat down to medium-low. Simmer between 2 and 4 hours. Strain, and reserve the resulting stock to add as the liquid portion for a future batch of broth or stock.

Store remouillage in a tightly sealed container in the fridge for up to 5 days or in the freezer for up to 6 months.