History of Sweet & Sour Pork · Ku Lou Yok 咕嚕肉的歷史

Ku lou yok known as sweet and sour pork in English is a Cantonese food icon found across the world in various versions. Ku lou yok is a flexible dish that can take on many tweaks without losing its authenticity or identity.

As a Cantonese, sweet and sour pork is a familiar, comfort dish to me. So, it's a blessing that sweet and sour pork is widely available and affordable in North America when I had to stay there for a while. 

I am very fond of Panda Express' sweet and sour pork (founded 1983 with over 2300 outlets now) 🤭 But, Panda Express discontinued sweet and sour pork in 2014 🤔

Origins

Sweet & Sour Pork Ribs

Sweet and sour pork in its most common boneless pork cube form is a fairly recent creation. However, its origin is a little obscure - meaning, it is all based on legend, not evidence. According to one theory, its precursor is 糖醋排骨 or sweet and sour pork ribs. 

During the Qing dynasty (1644 - 1911), sweet and sour pork ribs was popular with Westerners living in the port city of Canton (Guangzhou). However, Westerners don't like bone in their food, so chefs supposedly from Chencun village 陈村 in Shunde district, Guangdong, switched the ribs to pork cubes instead. The new dish was called 古老肉 (literally ancient pork), then later 咕咾肉, 咕嚕肉 in Chinese. 

According to urban legend 古老 is the Cantonese way of saying "good" as the chefs heard their Western customers described their sweet and sour pork as "good, good, good" 🤔 In line with this created for Westerners origin theory, "ku lou" could be a homophone for "gweilo or gwai lou (devil man)"  or "koh lou (tall man as Westerners are generally taller than Chinese men) ".

Another legend says 咕嚕, 咕嚕 is the growling sound of empty stomachs craving for sweet and sour pork.

Alternatively, the name 古老肉 is said to come from the term 古卤 which means "old sauce" because sweet and sour sauce has a long history.

In another theory, 古老肉 or "ancient meat" could simply be a nod or reference to its precursor, 糖醋排骨 sweet and sour pork rib as the "ancient meat" dish.

There is yet another theory that sweet and sour pork was derived from a northern Chinese dish from Harbin, known as 锅包肉. It's flour battered pork slices deep fried and served with julienned ginger and leek garnish with a sweet and sour sauce made with sugar and white vinegar. When it came to the south over a century ago, the southerners just made it more elaborate and colourful with more garnishes and ingredients in the sweet and sour sauce.

Ku lou yok came to North America with Cantonese labourers who came for the California Gold Rush and to build the Transcontinental Railway. Over 300,000 Cantonese labourers came between 1852 to 1882, before the Chinese Exclusion Act halted the flow.

To survive, Chinese eateries and take-outs pitched their fare to non-Chinese audiences leading to dishes like choy suey and Americanised sweet and sour pork which they tweaked to local palates. North American sweet and sour pork is sweeter and bright red in colour which is achieved with ingredients like Kool-Aid. The main selling point of Chinese food in America like sweet and sour pork at that time was quick, cheap and tasty - a reputation American Chinese food hasn't fully shaken off.

Whatever its origin, from these theories, ku lou yok is inherently a versatile and flexible dish which is amiable to tweaks and adaptations in response to the market or local conditions. Ku lou yok is itself an adaptation of sweet and sour pork ribs or 锅包肉.

Basically, the sweet and sour pork dish is made up of three parts: 

1. Deep fried pork cubes, 
2. Stir fried garnishes, 
3. Sweet and sour sauce.

Within these three parameters, there are many variations and possibilities.

Pork Cubes

The most common cut for the pork cube is the pork belly for its layers of fat and lean meat. Meat to fat ratio is today around 7:3, though very lean meat is becoming more common. Over the years, chefs have used many variations including rolled bacon slices, pork leg, collar, jowl, 飛機肉, 猪争, 不见天, 猪爽肉, etc. Chicken and fish are used for non pork versions.

The pork cubes are marinated in a blend of sugar, pepper, salt, rice wine, rose wine, light soy sauce, egg, fermented bean curd, sesame seed oil, etc. A blend of cornstarch and wheat flour is sometimes included to make a thicker marinate.

The marinated pork cubes are coated with either one or blend of 薯粉 potato flour, 玉米粉 corn flour, 面粉 wheat flour, 粘米粉 glutinous rice flour, even bread crumbs 🤔, etc. The flour coated pork cubes are deep fried to a golden brown crisp outside.

There's even pork cubes coated with charcoal powder for the gimmicky black rocks look to attract a new generation of customers for restaurants.

The pork cubes are deep fried twice to get that crispy outside, tender inside effect. Alternatively, the pork is fried once, but the heat is lowered mid way, then turned up again to drive out excess oil and to crisp the outside.

Garnishes

The traditional garnish for this dish is 五柳菜 five vegetables but this is very rarely seen or is extinct in Singapore sweet and sour pork. The five vegetables are pickled ginger 酥姜, allium 荞头, raw papaya 青木瓜, carrot 红萝卜 and cucumber 青瓜.

Today, the "five vegetables" often include none of the traditional 五柳 but some combination of green / red / yellow capsicum (bell pepper), chili pepper, pineapple, onion, tomato, cucumber, spring onion, etc.

Garnishing with lychee is growing in popularity.

Sauce 糖醋酱

The sweet and sour sauce is the soul of the dish, and there are many ways to achieve the sweet and sour taste profile. Sometimes, controversies arise over which ingredients are critical or the best for a good sweet and sour sauce.

The sweet and sour sauce is usually made with a combination of ketchup, sour plum sauce, mixed fruit jam, chili sauce, white vinegar, black vinegar, HP sauce, lemon juice, malt sugar, etc. Every restaurant have their own secret recipe and ideal proportioning of ingredients. Some have red yeast rice for red colour, 冰片糖 for smokey caramelised taste, the possibilities limited only by the imagination of the chef. 

At Tonny Restaurant in Singapore, they use sugar, rice vinegar, ketchup, hawthorn, plum sauce, and Colmans O.K. sauce.

Before the days of ketchup, the sourish effect was achieved with hawthorn berry to make 山楂糖醋酱. Some swear by hawthorn berry 山楂 and believe that it cannot be done without or substituted.

The sauce is prepared by sautéing in a hot wok with a bit of sizzling oil. In one variation, the sauce is a reduction of vegetable stock (pineapple, various capsicum) blended with ketchup, etc.

Read about the history of ketchup and why it is so loved in Asia 👈 click

The pork cubes, garnishes and sauce are tossed and folded together in the wok until the pork cubes are completely and fully enveloped with sweet and sour sauce.

In the old days, sweet and sour pork was more saucy as people down a lot of plain rice with the sauce. Nowadays, the pork cubes are not flooded with sauce as people eat less, little or even no rice at all.

Recipes

These are some currently trending recipes.

拔丝咕噜肉 Sweet and Sour Pork with Stretchy Sticky Sauce.

The marinated pork cubes are coated with 脆粉 "crisp flour". 脆粉 "crisp flour" is a blend of 玉米粉 corn flour, 面粉 wheat flour, and 粘米粉 glutinous rice flour. The battered pork cubes are deep fried to a golden brown crisp outside.

The sweet and sour sauce which is made with sugar, white vinegar, ketchup, corn starch and water. The sweet and sour sauce is caramelised by sautéing till the sugar becomes gooey, stretchy and sticky.

When the sweet and sour sauce is ready, the deep fried battered pork cubes are tossed and folded with the sweet and sour sauce till it is fully coated.

冰鎮咕嚕肉 Sweet and Sour Pork with Ice

In the ice version, the sweet and sour pork dish is made in the same way as other recipes. However, more malt sugar is used in the sauce. The cooked sweet and sour pork is served buried in ice which will crisp the maltose laced sauce slightly, giving the sweet and sour pork a subtle glassy crisp outside. There's also a contrast of cold outside and warm inside the fried pork cube. Whether this makes the dish more delicious is subjective but it does pique many people's curiosity to give it a try at least once.

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Conclusion

This iconic Cantonese dish has stood the test of time and travelled well across the oceans. Its sweet and sour taste is widely appealing, including to Western palates.

Its recipe is flexible, so many different ingredients can be added or substituted.

The bottomline is to achieve a dish where the pork cubes are crisp outside, juicy inside, and porcine sweet. The garnishes are crunchy, juicy and complements the pork and sauce. The sauce is a tasty balance of sweet and sour.

So beyond this, which version is superior or inferior is really moot. You know...., for example, don't use 五柳菜 can the dish still be considered "authentic"? Why not? As long as you enjoy it, just eat and be happy lah!

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Written by Tony Boey on 3 Dec 2023

References

锅包肉

水晶咕咾肉

生炒骨 脆炸排骨秘技

山楂咕嚕肉

拔丝咕噜肉