Can you use olive oil in soup? When to add oil to slow-cooked and quick-boiled soups in Hong Kong homes
Hong Kong people make soup almost every day: slow-boiled old-fire soups simmered for hours, quick-boiled soups ready in half an hour, clear chicken soup, vegetable soup and tomato egg drop soup are all household staples. In recent years many families have started using extra virgin olive oil, and the first question is often: “Can you use olive oil in soup? Will it go bad as soon as it boils? When should you add the oil?”
The answer: yes, you can. The key is not “whether you can use it”, but when to add the oil. The fruity and phenolic aromas of extra virgin olive oil fade noticeably with long, hot boiling; most clear soups and quick-boiled soups are better served by drizzling the oil in after turning off the heat, keeping the aroma on the surface. For old-fire soups that need a little fat for a smoother mouthfeel, you can also add it just before serving.
The short answer:
- Quick-boiled soups, clear soups, vegetable soups: once the soup is done, take it off the heat, then drizzle in about ½–1 teaspoon of extra virgin olive oil.
- Old-fire soups: there’s no need to simmer the oil in the pot for hours; just drizzle a little before serving or after ladling into bowls.
- Soup bases that need aromatics fried first (such as tomato egg drop soup or hot and sour soup): briefly stir-fry the ingredients in a little olive oil on medium-low heat, then add water and boil; you can still drizzle in some raw oil at the end for aroma.
- Smoke and bitterness mostly come from heat that is too high or oil that is no longer fresh, not from “olive oil being unsuitable for soup”.
Key points (30-second version):
- Extra virgin olive oil is suitable for soup, but in most cases it is best drizzled in after turning off the heat, rather than boiled in the pot for a long time.
- Five Hong Kong home examples: vegetable soup, tomato egg drop soup, clear chicken soup, winter melon and barley soup, hot and sour soup.
- Common mistakes: simmering extra virgin in old-fire soup for hours; mistaking smoke for “the oil has gone bad”; keeping the oil bottle by the stove where it gets hot.
- Storage and freshness matter just as much: see “How to judge olive oil freshness and oxidation?” and “How to store olive oil?”.
Why use oil in soup? What does olive oil do in soup?
| Role | Explanation |
|---|---|
| Smoother mouthfeel | A little fat makes a clear soup less “watery” and rounder in the mouth |
| Carries aroma | Fat-soluble aroma molecules need fat to carry them; drizzled in after turning off the heat, the fruity aroma stays on the surface more easily |
| Layers of flavour | Extra virgin brings grassy, fruity notes and a slight pepperiness, adding a layer of aroma to light soups and reducing the need for extra lard or chicken fat |
| One bottle, two uses | The same oil can be used for stir-frying, dressings and drizzling over soup, making it easier to finish within the recommended period after opening |
Soup is usually cooler than the peak temperature of a wok surface when pan-frying or stir-frying, but staying close to boiling point for a long time still gradually drives off the volatile aromas. So “can you use it” and “how to make it fragrant” are two different things: you can add oil, but most of the time adding it after boiling is finished is better value than throwing it into the pot at the start.
For general principles on cooking performance and temperature, see “How does extra virgin olive oil perform in cooking?”; for high-heat pan-frying and stir-frying, see “Can you pan-fry with olive oil over high heat?”.
When to add oil: old-fire soups, quick-boiled soups and clear soups
1. Quick-boiled / clear soups (about 15–40 minutes)
Put the ingredients in the pot, add water, bring to a full boil, season, and it’s done. The worst thing for this kind of soup is adding a lot of oil at the start: the oil floats on the surface, its aroma fades after a long boil, and the soup easily turns greasy.
Suggestion: soup done → turn off the heat → drizzle ½–1 teaspoon of extra virgin olive oil into the bowls or straight into the pot → stir gently or let the film of oil spread naturally → eat straight away.
2. Old-fire soups (several hours on a low flame)
The point of old-fire soup is the flavour that bones, meat and herbs release over a long time. If you put extra virgin olive oil into the pot early and simmer it for hours, its fruitiness will almost completely disappear, doing little for the flavour and wasting a more expensive oil.
Suggestion: no need to add olive oil while the soup is cooking. Before serving, or into each person’s bowl, drizzle a little (about ½ teaspoon); the soup gains a layer of fresh fruitiness without overpowering its original taste.
3. Soup bases that need aromatics fried first
For soups where tomato, garlic, ginger slices or chilli are fried until fragrant before adding water, briefly stir-fry them in a little olive oil on medium-low heat for 30 seconds to 1 minute, then add water and boil. You can still drizzle in some raw oil once it’s done.
Principle: keep the frying brief, and don’t let the heat get so high that it smokes continuously; if it smokes, take it off the heat to cool down first. For smoke signals, see “Does olive oil smoke when stir-frying?”.
Five Hong Kong home soups: how to use olive oil
The quantities below serve about 2–3; the amounts of oil are home-cooking guides and can be adjusted to taste.
1. Seasonal vegetable soup
- Choi sum, spinach, lettuce or watercress, with a few slices of ginger.
- Boil in water or clear stock until the vegetables soften, then season with salt.
- After turning off the heat, drizzle in about 1 teaspoon of extra virgin olive oil.
Tip: vegetable soup is light on its own, so drizzling oil in after turning off the heat makes the fruitiness easiest to taste; too much oil will mask the vegetables.
2. Tomato egg drop soup
- On medium-low heat, briefly stir-fry tomato chunks in about 1 teaspoon of olive oil until juicy, then add water (or stock) and bring to the boil.
- Pour in beaten egg to form egg ribbons, and season with salt and a little white pepper.
- After turning off the heat, you can drizzle in another ½ teaspoon of oil for aroma.
Tip: the sweet-sour tomato pairs very well with olive oil’s fruitiness; frying the tomatoes is a short, medium-low-heat step, similar to frying an egg.
3. Clear chicken soup
- Blanch the chicken pieces, then simmer gently or cook on a low flame until the soup is clear and sweet, adding ginger and red dates (optional).
- Skim off the surface fat, then season.
- Before serving, drizzle about ½ teaspoon of extra virgin into each bowl.
Tip: chicken soup already contains fat, so olive oil is just to “lift the aroma”, not to add more greasiness; for the old-fire version, too, it’s best drizzled in once it’s done.
4. Winter melon and barley soup
- Winter melon chunks and barley, with or without lean pork, simmered in water until the melon turns translucent.
- Season, then turn off the heat.
- Drizzle in about ½–1 teaspoon of olive oil.
Tip: for light, soothing soups like this, a little oil makes them taste less thin; don’t add a lot of oil before the barley has softened.
5. Hot and sour soup (home-style)
- On medium-low heat, fry shredded ginger and wood ear fungus (optional) in about 1 teaspoon of olive oil until fragrant, then add stock.
- Add tofu, egg ribbons, vinegar, white pepper and a little cornflour slurry to thicken.
- You can drizzle in a little more oil before serving.
Tip: hot and sour soup is strongly flavoured, so use less olive oil rather than more, so it doesn’t overpower the vinegar; medium-low heat is enough.
Three common mistakes
| Mistake | Result | How to improve |
|---|---|---|
| Simmering extra virgin in old-fire soup for hours | The fruitiness disappears and only the greasiness remains | Don’t add oil during cooking; drizzle it in before serving or after ladling into bowls |
| Heating the oil on high until it smokes before adding water or vegetables | The oil turns bitter and the kitchen fills with fumes | Fry aromatics on medium-low heat; take it off the heat if it smokes continuously |
| Keeping the oil bottle by the stove / window for long periods | Heat and light speed up oxidation, and the taste deteriorates | Store it sealed in a cool cupboard; see the storage article |
For signs of oxidation and spoilage, read further in “How to judge olive oil freshness and oxidation?”; for choosing oil, see “How to choose extra virgin olive oil?” and “What’s the difference between cold-pressed and refined olive oil?”. If you want to use the same oil for dressings, see also “How to use extra virgin olive oil in dressings?”.
Mastri: from drizzling over soup to everyday pan-frying and stir-frying
Soup usually uses very little oil, but once a bottle is open you still want one oil that covers drizzling over soup, dressings and medium-low-heat quick stir-frying, so your kitchen doesn’t fill up with half-used bottles.
Mastri Extra Virgin Cold-Pressed Olive Oil 750ml:
- Grade and ingredients: cold-pressed extra virgin; the ingredient list is only 100% extra virgin olive oil; no additives, no artificial flavourings, non-GMO ingredients (refer to the product page).
- Uses include hot soup: the product page suggests drizzling it directly over salads, pasta, hot soups, steamed seafood or using it for dipping bread; it is also labelled as suitable for household low-to-medium-heat quick stir-frying, frying eggs or tossing.
- Stated smoke point: the product page states about 190–210°C (a brand statement, not an independent lab verification for any particular soup).
- Flavour: the product description mentions fresh fruitiness with grassy and green apple notes and a gentle pepperiness, so it doesn’t overpower a clear soup.
- Storage: a cool place at room temperature is fine; best used within 6 months of opening (refer to the product page).
Boil up a pot of vegetable soup tonight, drizzle in half a teaspoon of Mastri after turning off the heat, and smell the fruitiness rising from the surface.
Frequently asked questions (FAQ)
Q1: Can you use olive oil in soup?
Yes. Extra virgin olive oil can be used in soup, but for most clear and quick-boiled soups it is best drizzled in after turning off the heat for aroma; for old-fire soups, drizzle it in before serving — there’s no need to simmer the oil in the pot for hours.
Q2: Should I add olive oil to old-fire soup at the start?
Generally, no. Long boiling greatly weakens extra virgin’s fruitiness. Once the soup is done and seasoned, simply drizzle a little into the pot or the bowls.
Q3: Will the oil be “ruined” by boiling the soup?
Short periods on medium-low heat, or drizzling it in after turning off the heat, are safe home uses. What really affects the flavour is usually continuous high heat with smoke, or oil that has already oxidised and changed taste. If it smokes, take it off the heat to cool down, rather than concluding that “olive oil can’t go in soup”.
Q4: How much olive oil should I drizzle into a bowl of soup?
As a home guide, about ½–1 teaspoon. Use less for clear chicken soup or old-fire soups that already contain fat; a light vegetable soup can take closer to 1 teaspoon. The aim is a thin sheen and fruity aroma on the surface, not a thick layer of oil.
Q5: Can I use olive oil instead of lard or chicken fat to fry aromatics?
Yes, as a home substitute, especially for briefly frying ginger, garlic, tomatoes and the like. Use medium-low heat and keep it short; for dishes that rely on a rich animal-fat aroma, the flavour will still differ, so choose according to taste.
Q6: Will drizzling oil in after the soup boils “destroy” its nutrients?
This article makes no medical or nutritional benefit guarantees. In kitchen practice, drizzling oil in after turning off the heat is mainly to preserve aroma and mouthfeel; boiling it in the pot for a long time makes the aroma dissipate more easily. Choosing a fresh, well-stored extra virgin is more practical than fixating on any single number.
Disclaimer
This article is general dietary and kitchen education, offering practical reference for using extra virgin olive oil in old-fire soups, quick-boiled soups and everyday clear soups. Oil amounts, timings and heat levels are general suggestions only and depend on your cooker, the amount of soup and your taste. The content does not constitute medical advice, nutritional therapy or food-therapy advice, and does not guarantee detox, liver protection, cholesterol lowering or any disease-improvement effect. Smoke point and usage statements are cited from the brand’s product page and public educational materials for general reference only. If you have special dietary restrictions or medical conditions, please consult a registered doctor or dietitian.
