Know Your Sauces
Cooking Skills: Sauces 1
Chapter 1 · Know Your Sauces
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The basics
A sauce is a flavoured liquid with the right thickness. There are only five ways to get that thickness. Starch (cornflour or arrowroot mixed with cold water) gives a clear, glossy sauce. Flour cooked in butter, a roux, gives an opaque, creamy sauce. Reduction boils away water until the sauce is stronger and thicker. An emulsion whisks fat into liquid. A purée blends soft cooked vegetables into the liquid. Most sauces use one method and a few use two.
Taste is as important as thickness. Taste a sauce at the end and ask four questions: does it need salt (flat), acid (heavy or dull; add lemon or vinegar), sweetness (too sharp; add a pinch of sugar or honey) or fat (thin and harsh; add butter or cream)? Mayonnaise and hollandaise are in Cooking Skills: Eggs 2, chapters 7 and 8.
The method
- Decide how thick you want it before you start: it should coat the back of a spoon, or pour like single cream.
- Mix cornflour with cold water first, then stir it into a hot sauce and boil for a minute.
- Reduce in a wide pan: a wider surface means faster evaporation.
- Add salt last, especially if the sauce is reducing, because it gets saltier as it shrinks.
- Taste, then adjust with salt, acid, sweetness or fat, one at a time.
| Method | Examples | Looks | Watch out for |
|---|---|---|---|
| Starch | Soy glaze, stir-fry sauces | Clear and glossy | Lumps if added to hot liquid |
| Flour (roux) | White sauce, gravy | Opaque and creamy | Floury taste if undercooked |
| Reduction | Stock glaze, pan sauces | Dark and intense | Too salty if reduced too far |
| Emulsion | Butter sauce, dressings | Pale and creamy | Splitting if too hot or too fast |
| Purée | Vegetable sauces, soups | Smooth, matte | Hot liquid in a blender |
Blending hot liquids: hot liquid expands in a sealed blender and can blow the lid off and scald you. Let it cool for a few minutes, fill the jug no more than half, hold a folded cloth over the lid, and start on low. A stick blender in a deep pan avoids the problem.
Allergens: soy sauce contains soy and gluten; butter is milk; flour contains gluten; stock may contain celery. Use cornflour, tamari or plant butter where needed.
Try it
A cornflour-thickened soy glaze
A shiny, savoury glaze for noodles, rice, vegetables or grilled meat. The cornflour is mixed with cold water first, so it blends smoothly, then boiled for a minute to lose its raw taste.
Ingredients (4 portions)
- 3 tbsp soy sauce
- 150 ml water or low-salt stock
- 1 tbsp honey
- 1 tsp fresh ginger, grated
- 1 garlic clove, crushed
- 2 tsp cornflour
- 2 tbsp cold water
- 1 tsp rice vinegar
- Put the soy sauce, water or stock, honey, ginger and garlic in a small pan and bring to a simmer for 3 minutes.
- Mix the cornflour with the cold water until smooth. Take the pan off the heat, stir in the cornflour mixture, then return to the heat and stir until it boils and thickens, about 1 minute.
- Stir in the vinegar, taste, and serve over rice, noodles or grilled vegetables.
Allergens: soy sauce contains soy and gluten. Use tamari for a gluten-free glaze.
Cornflour: cornflour thickens as it boils. Don't boil it for much longer than a minute, or it thins again.
A butter and lemon sauce
A light, glossy sauce for fish, chicken or vegetables. The lemon and water are boiled down a little, and then cold butter is whisked in a cube at a time, so the fat and liquid join into a creamy emulsion. Keep it gentle; boiling it will make it split.
Ingredients (4 portions)
- 1 lemon, juiced
- 4 tbsp water
- 60 g cold butter, in small cubes
- 1 tbsp chopped parsley
- 1 pinch flaked sea salt
- Simmer the lemon juice and water in a small pan for 2 to 3 minutes until reduced by about half.
- Turn the heat right down. Whisk in the butter one cube at a time, waiting for each to melt before adding the next, until the sauce is creamy and pale.
- Take it off the heat, stir in the parsley and salt, and serve at once. Don't boil it again.
Splitting: if the sauce turns oily, take it off the heat and whisk in a spoonful of cold water to bring it back.
Milk: butter is dairy. A plant butter works, but the sauce may be less stable.
A reduced stock glaze
Good stock boiled down to a quarter of its volume becomes a dark, savoury glaze that coats the back of a spoon. It needs no thickener. Use low-salt stock, because the salt becomes stronger as the liquid shrinks.
Ingredients (4 portions)
- 400 ml low-salt chicken stock
- 1 tbsp balsamic vinegar
- 1 tsp honey
- 2 sprigs of thyme
- 1 tsp butter
- Put the stock, vinegar, honey and thyme in a wide pan and bring to a boil. Boil steadily for 10 to 12 minutes, until reduced to about 100 ml (a quarter) and it coats the back of a spoon.
- Remove the thyme, whisk in the butter, taste and add a little salt only if needed. Serve over roast vegetables, sausages or chicken.
Stock and salt: shop stock cubes and granules are very salty. Use low-salt stock, make it up weaker than the pack says, and taste before adding any salt, especially if you plan to reduce the sauce.
A blended carrot and ginger sauce
No flour or cornflour here: the cooked vegetables themselves make the sauce thick. The potato adds body, and a squeeze of lemon at the end brings it to life. Serve with fish, chicken, eggs or rice.
Ingredients (4 portions)
- 1 tbsp olive oil
- 1 onion, chopped
- 3 carrots, chopped
- 1 small potato, peeled and chopped
- 1 tbsp fresh ginger, grated
- 500 ml low-salt vegetable or chicken stock
- 1 tsp lemon juice
- 1 pinch flaked sea salt
- Cook the onion in the oil for 5 minutes. Add the carrots, potato and ginger and cook for 2 minutes more.
- Add the stock, bring to a boil, then cover and simmer for 20 minutes until the vegetables are very soft.
- Cool for 5 minutes, then blend until smooth, adding more stock or water if it is too thick. Add the lemon juice and salt and taste.
Hot sauce: a thickening sauce bubbles and spits, and hot sauce sticks to skin and burns worse than water. Stir with a long spoon, keep your face back and turn the handle of the pan inwards.
Stock and salt: shop stock cubes and granules are very salty. Use low-salt stock, make it up weaker than the pack says, and taste before adding any salt, especially if you plan to reduce the sauce.
Experiments
Cornflour or flour
Clear and cloudy.
- Thicken two small pans of stock, one with cornflour mixed with water and one with a paste of equal parts butter and flour, and compare.
Look for: The cornflour sauce is clear and glossy and thickens quickly; the flour sauce is cloudy and matt, and needs a few minutes of simmering to lose its raw taste.
Reduced or thickened
Boiled down or thickened.
- Boil one pan of stock down to a quarter and thicken another with cornflour, then taste both.
Look for: The reduced stock is more intense and saltier; the thickened one is milder. Use reduction for flavour and starch for body.
Salt, acid and sweetness
Finish a plain sauce.
- Divide a plain sauce in three and add salt to one, lemon juice to another and a little honey to the third.
Look for: Each changes it in a different way. Learning which one a flat sauce needs is the most useful skill in this course.
Hot or cold thickener
Lumps on purpose.
- Stir cornflour straight into a hot pan of stock in one, and mix it with cold water first in another.
Look for: The straight cornflour forms lumps; the slurry is smooth. Always mix starch with cold liquid first.
Tasting notes
| What I tried | Method or amount | What I saw | What I thought | Will I do it again? |
|---|---|---|---|---|
| Soy glaze | ||||
| Butter and lemon sauce | ||||
| Stock glaze | ||||
| Carrot and ginger sauce | ||||
| Cornflour or flour | ||||
| Reduced or thickened | ||||
| Salt, acid and sweetness | ||||
| Hot or cold thickener |
Troubleshooting
| Problem | Likely cause | What to do |
|---|---|---|
| Lumpy sauce | Starch or flour added to hot liquid | Whisk hard, then strain; next time mix with cold water first |
| Too thin | Not enough thickener, or not boiled | Boil a little longer, or add more cornflour mixed with water |
| Too thick | Over-reduced or too much thickener | Add a splash of water or stock |
| Too salty | Salted before reducing, or salty stock | Add water or unsalted stock, or a squeeze of lemon |
| Tastes of raw flour or starch | Not cooked long enough | Simmer for a few more minutes |
| Tastes flat | Needs salt, acid or sweetness | Add a little lemon or vinegar, then salt |
Stock and salt: shop stock cubes and granules are very salty. Use low-salt stock, make it up weaker than the pack says, and taste before adding any salt, especially if you plan to reduce the sauce.
Keeping sauces: cool a sauce quickly in a shallow container within 1 to 2 hours, press cling film onto the surface to stop a skin forming, chill and use within about 2 days. Reheat until steaming hot, stirring. Milk and cream sauces can split when frozen, so freeze other sauces instead.
- I can name the five ways to thicken a sauce.
- I can thicken with cornflour without lumps.
- I can reduce a stock to a glaze in a wide pan.
- I can whisk butter into a sauce without it splitting.
- I can taste a sauce and say whether it needs salt, acid, sweetness or fat.