What does the cold vs soft butter biscuits experiment test?

It tests one variable: butter temperature. The idea is that biscuits made with cold butter rise taller and flakier than ones made with soft butter.

40-minute experiment

Cold vs soft butter biscuits

Flaky layers need cold butter.

The idea

Biscuits made with cold butter rise taller and flakier than ones made with soft butter.

The one thing you change: Butter temperature

You need

2 cups flour
1 tbsp baking powder
1/2 tsp salt
6 tbsp butter, half cold and half soft
3/4 cup milk

Steps

Make two half batches. Cut cold butter into one and mix soft butter into the other.
Add milk, pat each out, cut rounds and bake at 220C for 12 minutes. Use oven mitts.
Let the biscuits cool for 5 minutes, since the steam inside burns, then split one from each batch and compare. Don't eat raw dough.

What you should find

The cold butter biscuits are taller with visible flaky layers. The soft butter ones are flatter and crumbly.

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The science behind it

Cold butter for flaky pastry

Pea-size chunks of cold butter stay solid in the dough. In a 200°C (400°F) oven they melt, the water in the butter turns to steam, and the steam pushes the…

Read the explainer

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