Why Vegetables Boiled in Stock Are Best Not Blended

When making stock, cooks usually remove and discard the vegetables, herbs and bones. The website Quora has addressed whether stock would turn out worse if everything were puréed with a hand blender, and why this is generally not recommended.

What happens during cooking

Stock-making relies on culinary extraction, a process in which flavour and aroma compounds from the ingredients pass into the water. Meat and bone stock also releases gelatin, which gives the liquid a pleasant, slightly gel-like consistency once it cools.

After several hours on a low heat, vegetables lose much of their original flavour and become soft, watery and fibrous. They have not lost all nutritional value, however: they still contain fibre and other substances, although their taste and texture may no longer be pleasant enough to serve on their own.

Why blending is not the best choice

When the cooked vegetables are blended, their fibres and tiny particles disperse into the liquid, making the stock cloudy and thicker. This does not necessarily make it less tasty, since the result depends on the amount and type of vegetables and the desired outcome. But if the aim is a clear, aromatic stock, blending is unsuitable.

Extra caution is needed when bones are in the pot. They must never be broken up with a hand blender, because sharp, hard bone fragments could end up in the liquid and are dangerous to swallow. Before blending, the stock should be carefully strained so that bones and other solid parts are fully removed.

If you want a thick soup

For a creamy soup, a different method is better: prepare and strain the stock, add fresh vegetables, cook them until soft, and blend them together with the liquid. This produces a flavourful, thick soup with a pleasant texture.

Clear, strained stock serves as a base for sauces and other soups. The cooked vegetables do not have to be thrown away; if their taste and texture are still pleasant, they can be used in a vegetable purée or in a filling.