The most common answer online to “how long do you steam grouper” is 8 to 10 minutes. That number is not wrong, but it leaves out a premise: it refers to a whole fish of about 600 g, placed straight into a steamer whose water is already at a full boil. For the very same cordia-seed steamed fish, a recipe site supported by Taiwan’s Ministry of Agriculture says 8 to 10 minutes in a steamer, while a home recipe using an electric cooker says 1.5 cups of water in the outer pot, 20 minutes of steaming and then 10 minutes of resting — more than three times as long, and both are right. The difference is not about who is more accurate. Three things — the cookware, the form of the fish, and whether there is anything lining the plate — make the same fish need completely different times. This page lays out Longhu grouper (Longhu hybrid grouper) from 400 g to 1,200 g — whole fish, fillets, steaks and heads — against steamer minutes and electric-cooker outer-pot water, and explains why the final test of doneness is core temperature rather than a stopwatch: Taiwan’s Food and Drug Administration (Ministry of Health and Welfare) sets 65°C or above for seafood, and the U.S. FDA sets 63°C for fish.
A Longhu grouper of about 600 g (1 Taiwanese catty) takes 8–10 minutes on high heat throughout once the water is at a full boil, then rests 1–2 minutes after the heat is off; add 1 minute for roughly every extra 75 g. Steaks or fillets 2–3 cm thick take about 6–8 minutes, boneless slices about 4–6 minutes, and a halved fish head 12–15 minutes. An electric cooker cannot copy these minutes directly — it switches off when the water in the outer pot boils dry, so what you set is the amount of water, not the time, and the fish sits inside during the warm-up while the cold water comes to a boil. A 600 g whole fish corresponds to about 0.5–1 rice measuring cup in the outer pot. But time is only ever a starting point; the real test is core temperature: Taiwan’s Food and Drug Administration (Ministry of Health and Welfare) sets 65°C or above for seafood, and the U.S. FDA sets 63°C for fish. Without a thermometer, push the thick end of a chopstick into the thickest part of the fish; if it goes through without effort, it is done.
Nobody copied it wrong. The five sources below are all verifiable recipes, yet their times range from 8 to 30 minutes. Put side by side, the differences turn out to come entirely from four variables, not from the fish itself. Once you understand this table, you will no longer need to ask “how many minutes exactly” — you will be able to work it out yourself.
| Source | Cookware and heat | Time | Why this number |
|---|---|---|---|
| GoFish (supported by the Ministry of Agriculture): giant grouper fillet steamed with cordia seeds | Steamer, fish added after the water boils | 8–10 minutes, then back in the pot to rest 1 minute | A 180 g fillet: thin, and in direct contact with plenty of steam |
| GoFish (supported by the Ministry of Agriculture): steamed grouper | Steamer, high heat | 8–10 minutes | A whole fish of about 600 g — the baseline for every number on this page |
| Amanda’s home cooking blog: grouper steamed with cordia seeds | Electric cooker, 0.5–1 rice measuring cup in the outer pot | 10–20 minutes | The electric-cooker time includes the warm-up while the cold outer-pot water comes to a boil |
| Homemakers Union Consumers Co-op: fish steamed with cordia seeds | 10-person electric cooker, 1.5 cups in the outer pot | 20 minutes, then 10 more minutes of resting after it switches off | Firm tofu and onion line the plate, so the whole plate has far more heat capacity |
| HK01 steamed fish recipe | Steamer, high heat | About 6 minutes for 1 catty, about 12 minutes for 2 catties | The Hong Kong method runs short, and the article states outright that stove power varies from home to home |
The four variables: ① cookware (a steamer takes the fish only at a boil; an electric cooker includes the warm-up) ② form (whole fish, steaks and slices differ greatly in thickness) ③ plate lining (tofu, onion and rice vermicelli absorb heat, so the whole plate takes longer) ④ stove power and plate thickness. The HK01 article itself says “the most direct way is still to ask the fishmonger when you buy” — precisely because these four things cannot be summed up in a single number.
The times below apply to white-fleshed fish with fairly thick skin and delicate flesh, such as Longhu grouper; every steamer column starts timing only “after the water is at a full boil”. The electric-cooker column gives the amount of water in the outer pot in rice measuring cups, not minutes — the next section explains why. Use every column together with the doneness cue in the last column; time is only a starting point.
| Form and weight | Steamer (high heat after boiling) | Electric cooker (outer-pot measuring cups) | Doneness cues and notes |
|---|---|---|---|
| Whole fish, 400 g | About 6–7 minutes | About 0.5 cup | Small fish overcook easily; better to open the lid early and check |
| Whole fish, 600 g (1 Taiwanese catty) | 8–10 minutes | 0.5–1 cup | Baseline. Rest 1–2 minutes after turning off the heat |
| Whole fish, 800 g | About 11–13 minutes | About 1 cup | Extrapolated from the baseline at 1 extra minute per 75 g |
| Whole fish, 1,000 g | About 13–15 minutes | 1–1.2 cups | Use the upper end for a thick-bodied fish, the lower end for a flat one |
| Whole fish, 1,200 g | About 16–18 minutes | About 1.5 cups | At this size, score the back two or three times |
| Steaks or cross-cut pieces (2–3 cm thick) | 6–8 minutes | About 0.5 cup | Thickness matters more than weight; measure the thickest piece |
| Boneless slices (about 1.5 cm) | 4–6 minutes | 0.4–0.5 cup | The form most easily overcooked |
| Fish head, halved | 12–15 minutes | 1–1.5 cups | Lots of bone and slow heat transfer; make sure the flesh near the bone is fully cooked |
⚠️ The baseline (a 600 g whole fish in 8–10 minutes, plus 1 minute for roughly every extra 75 g) is cited from the recipes and articles listed in the sources at the bottom of the page; the columns for whole fish of 800 g and above are linearly extrapolated from that baseline, not individually tested, so always confirm with core temperature. If the plate is lined with tofu, onion, rice vermicelli or a lot of sauce, the heat capacity of the whole plate rises noticeably: add time, and add half a cup to one cup of water to the electric cooker.
The appliance Taiwanese households use most to steam fish is actually the electric cooker, yet nearly every recipe that says “steam for 8 minutes” is talking about a steamer. These four points explain why the two cannot be swapped, and also why recommendations for outer-pot water range anywhere from half a cup to one and a half cups.
| Outer-pot water | Approximate steaming run | Suitable for | Notes |
|---|---|---|---|
| 1/2 cup | About 10 minutes | Steaks, slices, whole fish under 600 g | The amount most often used for steaming fish |
| 1 cup | About 15–20 minutes | Whole fish of 800–1,000 g | Takes about 15 minutes for the switch to pop up |
| 1.5 cups | About 20–25 minutes | Large fish, or a plate lined with tofu or onion | The amount used in the Homemakers Union cordia-seed steamed fish |
| 2 cups | About 30–40 minutes | Not needed for steaming fish; this is a stewing amount | Using it to steam fish will certainly overcook it |
⚠️ This table is a rule of thumb, not a guaranteed value. The pot size, thermostat condition, measuring-cup volume and room temperature of each electric cooker all affect the actual time; advice online for the same thing ranges from 1/5 cup to 2 cups. The first time you steam fish in your own electric cooker, use the lower amount of water and measure the core temperature right after the switch pops up; remember that combination and you will be accurate from then on. When topping up water, always add hot water — adding cold water makes the temperature inside the pot drop sharply.
Time changes with the cookware, thickness and starting temperature, but the temperature at which proteins denature does not. The four methods below run from objective to subjective; without a thermometer at home, the second one is good enough.
The time it takes heat to reach the center of the fish depends on “thickness”, not “weight”. Two fish of the same 800 g, one thick-bodied and one flat and long, can differ by three or four minutes in the time to cook through. Likewise, a fish going straight from the fridge into the pot and one brought close to room temperature differ in starting temperature by more than ten degrees, so the times naturally differ. That is why every rigorous recipe comes back to core temperature in the end, rather than giving you an absolute number of minutes.（Basis: the recommended core temperatures of 65°C or above for seafood from Taiwan’s Food and Drug Administration (Ministry of Health and Welfare) and 63°C for fish from the U.S. FDA.）
“The water must boil”, “raise the plate”, “don’t lift the lid” — you see these everywhere, but few people explain why. Once you know the reasons, you can decide for yourself what to adjust with a different fish or a different pot.
Steamed fish is mild on its own, so success or failure often comes down to the sauce. The six below are the styles most common in Taiwanese homes and restaurants; each gives ratios you can copy directly and the key move, and each states when it goes on — added before steaming or poured on after, they make two different dishes. The full step-by-step methods (including marinating and plating) are six home recipes on the advertiser’s product page; this page does not repeat them.
The most versatile style: salty with a hint of sweetness, a light amber color. The key is “don’t steam the fish with the sauce on it” — the fish releases liquid as it steams, and sauce poured on beforehand gets diluted into a plate of salty water.
After steaming When the sauce goes on｜ Just smoking Hot oil temperature
Taiwan’s most representative way of steaming fish. Cordia seeds are pickled tree fruits, salty with a sweet aftertaste, and their own liquid is a natural source of saltiness and savoriness. This is one of the few sauces that tastes better “steamed together with its liquid”.
Steamed together When the sauce goes on｜ 1.5 tbsp Cordia seeds with liquid
Like cordia seeds, this belongs to the “pickles steamed in” approach, but it is more noticeably sour and sweeter, and the steaming liquid takes on a fruity aroma. It suits fattier cuts, where the acidity cuts the richness.
Steamed together When the sauce goes on｜ 2 tbsp Fermented pineapple with paste
The method that best brings out the fish’s own flavor, and the hardest to get wrong. The whole dish tastes of just three things: the freshness of the fish, the amount of salt, and the temperature of the oil. It suits anyone steaming this fish for the first time who wants to know what it tastes like on its own.
After steaming When the sauce goes on｜ 2 tbsp Hot oil
The whole fish is covered with fermented chopped chili and steamed together, so salty, spicy and sour flavors all soak into the flesh. Because chopped chili is very salty, this style needs the least extra seasoning, but it is also the easiest to make too salty.
Steamed together When the sauce goes on｜ 3 tbsp Chopped chili
The strongest-flavored style, suited to those who like bolder tastes or eat it with rice. The salty, fermented aroma of the black beans masks fishiness, making it a safe choice for larger fish with a relatively noticeable fishy smell.
Steamed together When the sauce goes on｜ Fry first Black bean prep
Ratios are based on a whole fish of about 600 g. Steamed-fish soy sauce and cordia seeds are both salty, so reduce accordingly if you salt the fish beforehand, or the whole plate will be too salty. The ratios above are cited from the recipes listed under “Sources” at the bottom of the page.
Root cause：Fish inevitably releases tissue fluid as it heats. The problem is pouring the sauce over the fish beforehand and steaming them together — the sauce is diluted by that liquid, the whole plate ends up as a puddle of salty water, and the flesh itself has no flavor. Another source is not patting the surface dry after thawing before it goes in the pot.
Fix：Once cooked, pour off all the liquid on the plate first, then pour the pre-mixed sauce in along the edge of the plate. If the fish was salted beforehand, it will release liquid as it sits, so always pat it dry with kitchen paper before it goes in the pot. Sauces meant to be steamed with the fish, such as cordia seeds and fermented pineapple, are the exception, but remember to pour off the excess liquid all the same.
Root cause：Overcooked. Fish muscle fibers are short; once the proteins denature they contract sharply and squeeze the moisture out, and past that point there is no going back. Common reasons are “steaming five more minutes in case it is not done”, or lifting the lid repeatedly so the temperature keeps dropping and the total time is forced longer.
Fix：Use the lower-end time from the table, measure the core temperature when time is up, and take it out once it reaches 65°C; don’t push on by the clock. If it needs finishing, rest it after turning off the heat rather than continuing to steam on high.
Root cause：Heat needs time to reach the center, and what decides that time is thickness, not weight. A thick-bodied fish, or one taken straight from the fridge into the pot (low starting temperature), leaves the center clearly behind the outside. The head and the area around the backbone are especially slow, because the flesh around the bone is the densest.
Fix：For whole fish of 1,000 g and above, make two or three diagonal cuts at the thickest part to shorten the heat’s path; let the fish warm up for a dozen or so minutes before cooking rather than steaming it ice-cold; before taking it out, insert a probe into the thickest part to confirm, rather than judging by the surface.
Root cause：One of the main sources of fishiness is the bloodline meat — the dark strip of flesh along the lateral line, high in hemoglobin and fat. The second source is black membrane and residual blood inside the belly cavity that was not cleaned out. The third is the whole fish sitting in the bloody liquid it releases while it keeps heating.
Fix：During prep, scrape the black membrane out of the belly cavity, rinse away residual blood under running water and pat dry. Raise the fish on chopsticks or a steaming rack so the bloody liquid runs to the bottom of the plate instead of surrounding the fish. Slices of ginger placed under the fish, rather than all on top, remove fishiness more directly.
Root cause：Two reasons: first, the plate was not oiled, so the gelatin sticks straight to the ceramic surface at high heat; second, moving the whole fish to another plate with a spatula right after steaming — Longhu grouper skin is thick, but once its gelatin softens it tears easily.
Fix：Before steaming, brush a thin layer of oil on the plate, or lay down scallion pieces and ginger slices as a barrier — which also raises the fish and removes fishiness. If you need to move it, wait three minutes for the gelatin to set slightly, then bring it to the table on the same plate; that is the safest way.
Every time on this page is based on “the whole-fish weight after it is killed, scaled, gilled and gutted”. The Longhu grouper supplied by “YOUBAN” (Wei Quan Co., Ltd.), an advertiser on this site, comes already prepared and vacuum-packed, with the weight marked on every pack, so you do not need to work out the loss yourself; specs, prices and six home recipes are on their product page. See YOUBAN’s specs and home recipes ｜Order on LINE · ask about today’s stock @862zvofa
This page covers only the time and heat for steaming. The fish’s background and nutrition figures are on the fish guide page, advanced cross-cuisine methods are on the recipes page, soup has its own page, and product specs and prices are on the advertiser’s product page.
For a white-fleshed fish like Longhu grouper, a whole fish of about 600 g takes 8–10 minutes on high heat throughout once the water is at a full boil, then rests 1–2 minutes after the heat is off. Add 1 minute for roughly every extra 75 g. Steaks or fillets 2–3 cm thick take about 6–8 minutes, boneless slices about 4–6 minutes. But these are all starting values; the real test is core temperature: Taiwan’s Food and Drug Administration sets 65°C or above for seafood, and the U.S. FDA sets 63°C for fish.
1 Taiwanese catty is exactly 600 g, which is also the most common household portion. 8–10 minutes on high heat in a steamer is the figure given by the recipe site supported by the Ministry of Agriculture; a Hong Kong recipe says about 6 minutes for 1 catty, which runs short, because stove power and plate thickness vary from home to home. We suggest checking the core temperature once at 8 minutes, and if it is not enough, covering it again for another one to two minutes.
For whole fish or steaks under 600 g, about 0.5 rice measuring cup in the outer pot (a steaming run of about 10 minutes); for whole fish of 800–1,000 g, about 1 cup (about 15–20 minutes); if the plate is lined with heat-absorbing ingredients like tofu or onion, go up to 1.5 cups. 2 cups is a stewing amount and will certainly overcook fish. Electric cookers vary a lot, so the first time, use the lower amount and measure the core temperature after the switch pops up.
Not necessarily. The switch popping up only means the water in the outer pot has boiled dry; it has no direct connection with the fish’s core temperature. Most electric-cooker recipes go on to say “rest another 5–10 minutes”; that rest uses the residual heat in the pot to finish the core and is part of the design. After it pops up, rest it first, then open the lid and measure the temperature.
Not recommended. If it goes in frozen, the outside gets overheated while waiting for the center to thaw, so it ends up dry outside and just done inside, with an especially large amount of liquid. Thaw it completely and pat the surface dry before steaming. For vacuum-packed fish, note: open or cut the packaging before thawing; do not thaw it in the fridge still sealed in the bag.
The most versatile Cantonese ratio is 1.5 tablespoons oyster sauce, 1 teaspoon sesame oil, 1/2 teaspoon sugar and 2 tablespoons water, mixed well and poured on after steaming once the liquid on the plate has been poured off, then topped with shredded scallion and hot oil. The Taiwanese cordia-seed style uses about 1.5 tablespoons of cordia seeds with liquid, steamed together with shredded ginger. The key difference is timing: soy-sauce styles go on after steaming, while pickled styles (cordia seeds, fermented pineapple, chopped chili) are steamed together.
Because steam is at 100°C, while hot water that is not yet boiling is only 70–80 degrees. If the fish goes in before the water boils, it lingers in the low-temperature zone for several minutes, the proteins slowly release moisture, and the result easily turns dry and noticeably fishy. Wait until plenty of white steam is pouring steadily from the edge of the lid before adding the fish, and start timing from that moment.
It depends on the sauce. For plain scallion oil or Cantonese soy sauce, rubbing a thin layer of salt inside and out with 1 tablespoon of rice wine and leaving it about 10 minutes lets a base seasoning in and carries away some of the fishiness — but always pat off the liquid that seeps out before it goes in the pot. For already very salty sauces like cordia seeds or chopped chili, do not salt the fish separately, or the whole plate will be too salty.
Quite a lot. For the same 600 g, steaks cut 2–3 cm thick take only 6–8 minutes while a whole fish takes 8–10 minutes, because the distance the heat must travel differs — steaks are heated from both sides at once, while in a whole fish the heat has to pass through the full thickness of the body to reach the area near the backbone. For steaks, measure the thickest piece; do not go by total weight.
If it is your first time cooking this fish, we suggest starting with the simplest: steamed with scallion oil — it lets you learn what the fish tastes like on its own before deciding which direction to take. Longhu grouper has thick skin, plenty of gelatin under the skin and short-fibered flesh, so moist-heat methods like steaming, simmering and stewing suit it best, while pan-frying and roasting need more precise temperature control. For cross-cuisine methods and using different parts, see the recipes page on this site; soup has its own page.
The times and temperatures on this page are all cited from the sources above. In the table, the columns for whole fish of 800 g and above are linearly extrapolated from the baseline of “600 g in 8–10 minutes, plus 1 minute for roughly every extra 75 g”, not individually tested; in practice, go by core temperature.
Images on this page are AI-generated illustrations, not photos of actual dishes.
This page only describes the taste, texture and heating parameters of the ingredient and makes no health-benefit or medical-efficacy claims of any kind.
Page content last updated: 2026-08-12.
This page is written and published by HowBridge (0523.tw) and explains the time and heat for steaming grouper; see “Sources” above for references. Links on this page that lead to “YOUBAN” are on-site advertisements.
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Try another method
Beyond steaming, pan-frying, air-frying, hot pot, congee and New Year dishes each call for their own heat and timing. Every page includes step-by-step instructions and a timing chart.