Light soy, dark soy, sweet soy, soy, soy, soy – the sheer variety of soy sauces out there can overwhelm anyone (even the experienced cooks amongst us).
A staple in most Asian cuisines , soy sauce isn't one homogeneous condiment, contrary to what many might believe. It is a complex product, with many regional differences, and types of flavour and viscosity.
At a basic level, all soy sauces are made with soy beans, salt, water, and koji - a type of fungus cultivated from rice. Beyond that, even ingredients can differ, depending on where the soy sauce is made.
Why soy sauces vary
There are dozens of soy sauce types to choose from, with variances ranging from flavour to colour and viscosity. For example, Lee Kum Kee - one of the largest soy sauce producers globally - alone manufactures over 50 types of soy sauce.
Credit: Supplied: Lee Kum Kee
, often has a more refined, wine-like flavor because it’s brewed for longer. This extended fermentation produces more ethanol, contributing to its aromatic depth. It’s the perfect pairing for fresh foods like sashimi, or to create the cleaner flavours that Japanese cuisine is renowned for.
More about soy sauce
Boosted soy sauce
When it comes to Chinese soy sauces, there are many regional variations too, reflecting the country’s diverse geography.
Chef Tan Guo Hui, a Master Chef (not the reality TV show, but a title earned from and bestowed by the Chinese government, for his outstanding work in mentoring young chefs and promoting Cantonese cuisine) in Cantonese cuisine, tells SBS, “In Guangdong, the daytime is relatively longer. There is sufficient sunlight for fermentation, making the soybeans rich and aromatic. So Cantonese people especially love soy sauce. The soy sauce in the northern area, because there is snow, has a shorter fermentation process, making the soy sauce different from the one in the southern areas.”
This environmental difference explains why southern soy sauces tend to have richer, bolder flavours, while northern ones are lighter and more straightforward.
The science of soy sauce
What all soy sauces have in common though is that unique umami punch. And that comes from its nitrogen content. “A lot of countries actually use total nitrogen levels to distinguish between the grading of soy sauce,” Lam said. “The higher the nitrogen level, the most prestigious it is, the higher the umami taste.”
This grading system helps explain why some soy sauces taste more complex and savoury than others. The first draw of soy sauce – like the first press of olive oil – has the richest flavour.
Credit: Supplied: Lee Kum Kee
Sweet, light, and dark: when to use which soy sauce
One of the biggest lessons I’ve learned is that choosing the right soy sauce can make or break a dish.
“You won’t use a sweet soy for sashimi, for instance,” Lam points out. “It really depends on the application where you want to use it.”
Sweet soy, for example, is common in Southeast Asia (known in Indonesia as ) and works beautifully as a glaze or for adding a sweet/savoury one-two punch to your dishes without adding too much saltiness. Light soy, on the other hand, is a go-to for seasoning stir-fries or soups, while dark soy lends aroma and colour to braised dishes.
Lam sums it up perfectly: “You really need to start with three different types of soy. One sweet soy, one light soy, one dark soy.”
For Chef Tan, soy sauce is indispensable in Cantonese cuisine. “My favourite thing to do with soy sauce is of course to make a !” he says. “Even when I’m just making a simple dish of stir-fried veggies, it’s a must-have ingredient.”
Credit: Jiwon Kim
These conversations have led me to a renewed appreciation for the cultural and scientific complexity behind soy sauce. So now, when I reach for a bottle of soy sauce, I’m know I'm not just grabbing something to add saltiness to a dish. I’m choosing a flavour story, crafted by nature, science, and tradition.
The writer travelled to Hong Kong as a guest of Lee Kum Kee, where she absolutely geeked out on soy sauce.
