Hong Kong loves XO sauce or XO zoeng3 (XO醬), You can find this savoury, spicy and flavoursome sauce in many Chinese restaurants, from local eateries who add it to light bites like steamed rice noodle rolls, to high-end establishments who offer it to go with dim sum staples like turnip cake or har gau. It also goes particularly well with seafood dishes, accompanying scallops or working wonders in elevating the humble fishball. It can also pair with vegetables and stir fries. Some XO sauce makers suggest using it in hors d’oeuvres, and Western or Japanese food. Essentially, it’s a secret ingredient in Cantonese cooking and seasoning: it works with just about every dish. The possibilities are endless.
The origins of XO sauce, from its ingredients to its unusual name — which has no Cantonese equivalent — speak to the history of Hong Kong’s prosperity. The sauce itself consists of finely chopped shrimp and scallop with an oily consistency, and it tends to have a fiery red appearance thanks to the addition of spices and oil. Its taste is jam-packed with umami flavours that add a real kick to everyday dishes – even just a small amount could make those turnip cakes go from being slightly bland to super moreish.
There is no standardised XO recipe, but the standby ingredients include dried shrimp, dried scallop, red chilli pepper, garlic, shallots, canola oil and Chinese cured ham. Some use Yunnan ham, a dry-cured ham from the Yunnan province in China that has been referred to as the country’s answer to Italy’s Parma ham; others use Jinhua ham, a premium version of dry-cured meat produced using a specific breed of pig and named for Jinhua in Zhejiang province, where it originates from.
There are plenty of other variations. Dried chilli flakes are sometimes used instead of fresh chilli pepper, and it’s not unusual for an XO sauce to include shrimp paste in the seafood medley – a nice local touch, given the Hong Kong’s long history of making shrimp paste. There are also vegan versions that have sprung up in recent years, making use of shiitake mushrooms instead of seafood.
Although no one seems to know for sure, it is widely believed that the very first XO sauce was invented in 1986 at Spring Moon, the Cantonese fine-dining restaurant at the Peninsula Hotel in Tsim Sha Tsui, where it was served to guests as a complimentary condiment. The sauce is handmade without preservatives, which contributed to its growth in popularity with diners. Soon, customers were asking if they could buy the sauce directly, so in 1987, Spring Moon began to bottle and sell its XO sauce.
As for the name of the XO sauce, there is a story behind this, too. “Its name, ‘XO’, is a reference to premium brands of cognacs, to emphasise the high quality and the cost of the sauce,” says Gordon Leung, executive chef of Chinese cuisine at Spring Moon. In the Cognac region of France, different official grades are used to signify how old each type of cognac is. The “XO” variety means “extra old,” referring to a blend in which the youngest eau-de-vie — a sharp, colourless liquid that has been double-distilled — has been aged for at least six years.
Today, XO sauce is everywhere in Hong Kong. Major sauce manufacturers like Lee Kum Kee made bottles you can buy at any supermarket. There are also boutique brands such as the family-run Mrs. So’s XO Sauce, one of the few food and beverage brands in the city that still produces their stock locally in Hong Kong. As for the luxury option, five-star hotels and upmarket restaurants such as the iconic Yung Kee on Wellington Street create their own versions that can be purchased in bottles.
You can also find XO sauce in any city with an overseas Cantonese community, such as Vancouver and Los Angeles. Famed American restaurateur and chef David Chang, who owns the Momofuku Group, offers his own version of XO sauce.
Although XO sauce has travelled far and wide, The Peninsula still prides itself on being the creator of the original XO – even if the chef who was then at the helm of Spring Moon, Hui Sing, is no longer working with the hotel. “Most restaurants use more or less the same ingredients when making XO sauce – chillies, dried scallops, dried shrimps and spices,” says chef Leung. “But the differences [between Spring Moon’s and other XO sauces] lie in the preparation methods, the proportion of ingredients, the cooking times of each ingredient, and so on.”
Of course, these are trade secrets jealously guarded by each producer. So even if each brand of XO sauce had a similar makeup and preparation method, they all end up a little bit different to each other. But ultimately, they have the same purpose: to uplift a dish, and take its flavours to another level.
Note: Cantonese romanisation in this article is based on the jyutping system, which uses numbers to correspond to the six main tones in Cantonese.