First time posting on these forums, I dunno if something like this would be what y'all would be interested in. I usually post on Reddit over on /r/cooking, but sometimes these sort of hardcore 'food nerd' sort of recipes don't get a whole lot of traction.
Oyster sauce is a classic ingredient in Chinese (and Asian in general) cooking, but there seems to be a lot of FUD out there concerning how its made. The English internet is almost barren of proper recipes for oyster sauce, so I thought it might be helpful to fill in the gap a bit.
Traditional oyster sauce is the by-product of making dried oysters. When making dried oysters, generally what you’ll do is blanch the oysters for 15-30 minutes first and then leave them out to sun-dry. The old oyster sauce origin story goes that a man in Macao named Lee Kum Sheung was making dried oysters, but forgot that he’d left the poaching liquid on the flame. He found it hours later reduced into a brown gloop… trying it, he found it was delicious, and so oyster sauce was born. And while these sort of stories are almost always apocryphal, that is the essence of oyster sauce.
Yet over the years, the popularity of oyster sauce skyrocketed while the usage of dried oysters flagged. This has led to a conundrum: oyster sauce could be sold cheap when it was the previously unused byproduct of dried oysters. But it makes no sense with the roles reversed – dried oysters as a by-product of oyster sauce? For those unfamiliar with Southern Chinese cuisine, dried seafood (while awesome) can get fucking expensive, and dried oysters are no exception.
So in modern times, producers tend to take one of two shortcuts. First, many don’t reduce the poaching liquid nearly as much, then add a mix of caramel (to color) and starch and celluse gum (to thicken). This is actually the method that produces good oyster sauce, and is what smaller manufacturers do here in Guangdong. The second shortcut? Simply using oyster extracts and combining it with a shit-ton of sugar and additives. This is what larger producers do, making for a product that barely has any oyster flavor.
What we’ll do today though is keep things old school, as the traditional method is easiest to recreate at home. But word of warning: the yield isn’t very large (~1/2 cup or less) so it makes very little sense to make oyster sauce at home unless you’re sun-drying oysters anyhow. So I’ll also let you know how to sun-dry the oysters, and because you might be unfamiliar with the ingredient (awesome ingredient btw), I’ll also list out a recipe for a classic homestyle Cantonese dish – oyster braised pork ribs – to give an idea on how to use up dried oysters.
I do have a video to go along with this, but let me know if linking YT vids is frowned upon here and I'd be happy to edit it out.
Ingredients, Sun-dried oysters and Oyster Sauce:
Shucked Pacific Oysters (生蚝), medium sized, 1.5-2kg. So we’re using oysters that we bought pre-shucked at our local market. If you’d like to wash and shuck enough oysters to get 1.5-2kg of them that’d obviously be best, but that feels (1) extraordinarily painful and (2) like it’d cost a fortune abroad.
Water, 4.5L. For blanching the oysters in.
Sugar, ½ tbsp. Added near the very end. AFAIK the super traditional version wouldn’t contain sugar, but modern recipes (ours included) are balanced around oyster sauce with some sweetness to it. Plus, it helps give a little thickness and color.
Light Soy Sauce (生抽), 1 tsp. Optional. Some producers add soy sauce in with the oyster sauce, some don’t. I like adding a little bit, helps with the color.
Bog-standard mass produced oyster sauce (蚝油), ½ tsp. Super optional. I like adding a touch in order to make use of their thickeners – it’s a lot easier to buy Lee Kum Kee oyster sauce at the supermarket than it is to buy cellulose gum. Helps everything come together a bit. This is really only my personal approach though, obviously.
Process, Sun-dried Oysters and Oyster Sauce:
If using pre-shucked oysters, give the oysters a quick rinse. Transfer the oysters in a ‘dangling’ motion over to a pot with a bit of tap water. Rinse the oysters for ~3 minutes. You don’t have to go too crazy here – we’ll be filtering the sauce later, and we do want that brininess. If you’re using clean fresh oysters, you can skip this step, simply toss the oysters together with their brine in a big bowl.
Get a pot of water to a light simmer. Transfer the oysters over in a dangling motion. The ‘dangling’ motion is to minimize dragging over any sediment from the oysters.
Poach the oysters for 30 minutes, stirring periodically. Make sure the water isn’t boiling. Rapidly boiling water has the potential to destroy the integrity of the oyster. Think something that’s roughly ‘poached egg’ heat.
Fish out the oysters and place in a strainer to drain. If you have one of those cool bamboo strainers, that’s awesome as you can both strain and sun-dry in the same thing (plus, you get super authentic bonus points). I like straining it over the pot that I’ll eventually be cooking the oyster sauce in, so as to not waste any of the liquid. If not using a bamboo strainer, transfer over to a baking sheet.
If it is sunny out: place the bamboo strainer in a location with lots of sunshine. Sun-dry for a day, flipping the oysters once around noontime. If you’re living in a city like us, it’s a good idea to hang the strainer in order to avoid bugs or cats getting to your oysters. Note that if it’s partly cloudy, the oysters might need two days to dry out completely – simply bring them inside and store in the fridge overnight.
If it’s not sunny out: place the oysters on a baking sheet and toss in an oven. Put the oven on its lowest possible temperature (100C for us) and crack the door. ‘Bake’ for six hours, turning the oysters once halfway through.Sun drying is preferable because (1) it produces a better dried oyster in the end and (2) doesn’t waste energy like the oven method. But hey… sometimes you were planning on sun-drying and the weather’s just not cooperating. Better to waste a little energy than a lot of seafood, yeah?
Lightly oil a stainless steel pot, and pass the leftover poaching liquid through a fine mesh strainer lined with a tofu or cheesecloth. So the vessel that we used here was a stainless steel wok (very convenient for this particular job), but anything stainless steel will work great. Why stainless steel? Not overly sure actually, my best hypothesis is that as it’s a stick surface some of the liquid will caramelize and brown as its reducing. Cast iron would also work. Just don’t use something like a non-stick or a claypot.
Lightly simmer the liquid for 3-4 hours to let it reduce, scraping the sides down with a rubber spatula every 5-10 minutes. This reduction is undeniably annoying, so the million dollar question: why not just toss the thing at a heavy bowl and let it reduce much quicker? The answer is that you’ll lose way too much oystery goodness to the sides of the pot and your final yield will be much, much less. The more paranoid you are during this stage, the more oyster sauce you’ll get. That said, if your primary goal is making sun-dried oysters, you might be cool with a yield of a couple tablespoons. In that case, no need to be so paranoid.
Once it’s bubbled down into a brown liquid with consistency that’s roughly akin to a very thin pan sauce, add in the sugar, the soy sauce (if using) and the oyster sauce (if using). Let it cook together for ~2 minutes. Once its come together, jar it up. You should be looking at roughly ~1/3 cup oyster sauce by the end. Store in the fridge.
Again, I understand that this is not a very large yield from 1.5-2kg of oysters. The rule of thumb for traditional oyster sauce is that it yields 1g of oysters sauce from every 100g of oysters, so I was already relatively happy with the yield this approach gave.
Your final product will be something with a very clear and obvious ocean-y taste. My recommended use for it – to get the most bang for your buck – is to use it in recipes in conjunction with the standard mass produced stuff. Adding a ½ tsp or a tsp per tablespoon to your store bought oysters sauce will give you the flavor of something that is roughly equivalent to a good quality Guangdong-locally-produced oyster sauce.
And now… how to use those dried oysters:
Ingredients, oyster braised pork ribs:
This is a relatively simple homecooked dish that is very similar to a Cantonese banquet dish, oyster braised pork knuckle. We went with this one because it’s the sort of thing that’s easy enough to whip up on a week night.
Pork ribs, cleaved across the bone into 1 inch pieces (排骨), 500g.
Marinade for the pork ribs: ½ tbsp salt, 1 tbsp sugar, 2 tsp cornstarch (生粉), 1 tbsp rice wine (米酒), ½ tbsp light soy sauce (生抽), 1 tbsp oyster sauce (蚝油). Mix the cornstarch together with the rice wine and add it in as a slurry – this will coat the ribs much more evenly. Note that this is basically a bog-standard marinade, with two exceptions: first, the cornstarch ratio is a touch less, as this will be braised in the end; second, we’re adding some oyster sauce in in order to repeat that ‘oyster’ flavor a couple times in the dish. We’re using rice wine in this dish as it’s really nice with pork ribs, but you could use also use Shaoxing wine or even sake.
Dried oysters (蚝豉), 50g reconstituted with one cup hot, boiled water. We’ll be reconstituting this with hot water – we did want this to be an easy-ish dish after all. You could alternatively use cool water and leave it to reconstitute for much longer (6+ hours in place of the 45 minutes we did here here).
Garlic cloves, 3. Lightly smashed.
Seasoning for the braise: 2 tsp light soy sauce (生抽), 1 tsp dark soy sauce (老抽), ½ tbsp sugar, 1 tbsp oyster sauce (蚝油). The mix of light and dark soy sauce is mostly for color.
Rice wine (米酒), 1 tbsp to use when stir-frying and 3 tbsp to top off the braise. Again, feel free to use liaojiu/Shaoxing wine or sake (which is a type of rice wine) instead.
Process, Oyster braised pork ribs:
Give the dried oysters a quick rinse, then add the one cup of hot, boiled water. Let it reconstitute for at least 45 minutes. Again, you could alternatively use cool water, adding it in the morning and coming back to it for dinnertime.
Rinse the pork ribs under running water for 10 minutes. Rinsing the pork ribs extracts the myoglobin, giving the pork a cleaner look and flavor. Feels like it makes it a touch more tender too, but I have nothing to back that claim up.
Add the marinade ingredients to the pork and mix well. Marinate for at least 30 minutes. Remember to make a slurry with the cornstarch so that things don’t clump.
Stir fry, then braise: As always, when stir-frying first longyau (huaguo in Mandarin): get your wok piping hot (around steak searing temperature), shut off the heat, add in your oil (here about 1 tbsp), then give it a swirl to get a nice non-stick surface. Heat on high now:
Garlic cloves, in. Fry for ~15 seconds.
Pork ribs, in. Fry for ~1 minute, stirring only periodically. We do want the pork to develop a bit of browning.
~1 tbsp of rice wine, in. Pour over your spatula and around the sides of the wok to let it sizzle and quickly reduce.
Reconstituted oysters, in. Stir fry for ~15 seconds.
Soaking liquid from the dried oysters, in. Pour in through a strainer so that it’s not grainy. Give everything a quick stir.
Seasonings, in. Give it a quick stir.
Heat off. Transfer over to a claypot or some other suitable braising vessel, making sure that you get all the liquid.
Top off with the 3 tbsp of rice wine. Adjust the ribs to be relatively even. Some will be peaking out, that’s ok.
Flame on low. Cover, cook for 20 minutes.
Check on the pork ribs, making sure things aren’t bubbling too rapidly. Flip the ribs. Cook for 10 more minutes.
Enjoy some braised pork ribs. The dried oysters are my favorite part of this dish.
Note on economic considerations when making this outside of China:
I know oysters are expensive in the USA. One of my frustrations in the US is that food is generally (A) absurdly cheap processed shit or (B) absurdly expensive hyper-premium fare. Oysters are a perfect case – you either pay a pretty penny and get some (admittedly) really nice oysters, or turn to the can.
The way I would approach this is using frozen shucked oysters. I know those also aren’t cheap, from what I could find online they seem to run ~24 bucks per 16oz. That puts the cost of this recipe at ~72 dollars. Maybe I’m just poor, but that’s still… really expensive (by contrast, the cost of this recipe in China is CNY 135, or ~$20 US).
Still, the way to think of this isn’t $72 for a third of a cup of oyster sauce. The way to think of this is $72 to get a bunch of dried oysters, which are a great ingredient and pretty expensive if you bought them straight up. Then you get a bit of traditional oyster sauce on the side, which you can mix in with your standard bottled oyster sauce as I recommended above.
