Question 1

What is the difference between gelatine, pectin and agar?

Accepted Answer

Three setting agents from completely different sources, setting at different temperatures, with different textures — and they are **not interchangeable** in a recipe.

**Gelatine.** A protein derived from **animal collagen** — usually pig or cattle hide and bone.

**Sets on cooling**, around 15°C, and **melts at body temperature**, which is why gelatine desserts dissolve in the mouth. That melt is the defining characteristic and is difficult to replicate.

Sold as leaves or powder, graded by setting strength in **bloom**. Must be softened in cold water first, then dissolved in warm — **never boiled**, which weakens it.

**What defeats it:** raw pineapple, kiwi, papaya, figs and fresh ginger contain **protease enzymes** that digest the protein and prevent setting. Cooking the fruit destroys the enzymes, which is why tinned pineapple works and fresh does not.

**Not vegetarian.**

**Pectin.** A **plant** polysaccharide found in fruit cell walls, concentrated in apples, citrus peel and quince.

**Requires sugar and acid** to set, in fairly specific proportions — which is the whole basis of jam-making, and why recipes for low-acid fruit add lemon juice, and why reducing the sugar in a jam recipe stops it setting.

**Low-methoxyl pectin** sets with calcium instead, which is what low-sugar jam products use.

Sets to a spreadable, slightly elastic texture. Vegetarian and vegan.

**Agar (agar-agar).** A polysaccharide from **red seaweed**.

**Must be boiled** to activate — simply dissolving is not enough, which is the most common failure.

**Sets much more firmly** than gelatine, at a **much higher temperature** — it sets at around 35–40°C and does not melt until roughly 85°C. So an agar jelly is stable at room temperature and on a warm day, which gelatine is not.

**Texture is firm and brittle** rather than wobbly, and it does not melt in the mouth — which is why substituting it directly into a panna cotta gives a disappointing result.

Vegan, and used considerably less than gelatine by weight.

**Others:** **carrageenan**, also from seaweed; **cornflour and arrowroot**, which thicken rather than set; and **egg**, which sets by coagulation.

Question 2

Why does fresh pineapple stop jelly from setting?

Accepted Answer

Because pineapple contains bromelain, a group of enzymes that break down protein — and gelatine is a protein. The enzyme digests the very molecules that would otherwise form the gel network, so the

Question 3

What is the difference between jam, jelly and marmalade?

Accepted Answer

All three are fruit preserved with sugar. The difference is which part of the fruit ends up in the jar. Jam is made from crushed or chopped whole fruit cooked with sugar. It contains pulp and often

Question 4

What is the difference between stock and broth?

Accepted Answer

Traditionally, stock is made from bones and broth from meat. The practical difference that follows is body: stock sets to a jelly when cold, broth generally does not. Stock is simmered from bones,

Question 5

What actually happens when sugar caramelises?

Accepted Answer

Sugar melts, then breaks apart and recombines into hundreds of new compounds — which is why caramel tastes nothing like sugar and why the process is irreversible. The stages. Heated sucrose melts

Question 6

Why do bananas make other fruit ripen faster?

Accepted Answer

Because they release ethylene, a gaseous plant hormone that triggers ripening — and they release a lot of it. Ethylene signals fruit to convert starches to sugars, soften cell walls, change colour

Question 7

Why do different cuts of meat need completely different cooking?

Accepted Answer

Because the answer is determined by how hard the muscle worked — and that single fact predicts the connective tissue content, which predicts whether the cut wants fast heat or long slow heat. The

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