Question 1

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 jelly stays liquid.

Gelatine sets by forming a mesh of long protein strands that trap water. Bromelain cuts those strands into fragments too short to link up. The result is not a weak set; it is no set at all.

The fix is simple: **heat the pineapple first**. Bromelain is denatured by temperatures above roughly 70°C, after which it is inactive. This is exactly why **tinned pineapple works perfectly well in jelly** — it has been heat-treated during canning. Fresh or frozen pineapple has not, since freezing does not denature enzymes.

Several other fruits contain similar protein-digesting enzymes and cause the same problem raw: **kiwi** (actinidin), **papaya** (papain), **fig** (ficin), **mango** and **guava**. All are fine once cooked or tinned.

The same chemistry has a useful application. Bromelain and papain are the active ingredients in commercial meat tenderisers, and marinating meat in fresh pineapple or papaya juice genuinely does soften it. It is easy to overdo — leave meat in a pineapple marinade for hours and the surface turns unpleasantly mushy rather than tender.

It also explains why eating a lot of fresh pineapple can make your mouth feel raw. The enzyme is briefly digesting the proteins in your mouth's soft tissue. Harmless, and it stops as soon as you stop.

Agar, a seaweed-derived setting agent, is a carbohydrate rather than a protein and is unaffected by bromelain.

Question 2

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

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 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 5

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 6

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 7

Why does stock go cloudy?

Accepted Answer

Because agitation and high heat emulsify fat and suspend fine protein particles in the liquid, rather than letting them separate out — and once they are dispersed, they generally stay dispersed. What

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