Oil and agar agar: why pure oil does not gel

Adding agar agar to pure olive oil does not produce the same gel as water or juice. Agar needs a water phase in which to disperse and dissolve with heat. Understanding this difference avoids many unsuccessful trials.

Gel, emulsion or powder?

Define the aim before choosing an ingredient. An oil-containing gel can be designed as an emulsion with a water phase, but structure and stability depend on the whole recipe. This is different from pure oil gelled by agar alone.

A fat powder uses a different approach: tapioca maltodextrin can incorporate a fatty ingredient and change its presentation. The amount depends on the fat and the product used; one ratio does not suit every formula.

Distinguish two applications

The truffle oil powder recipe uses fat absorption. Oil air is instead an aerated preparation with a specific formulation. The method for one cannot simply be applied to the other.

For a pearl with a liquid centre, consider a spherification recipe suited to the base composition. Pearls made by dropping an agar solution into cold oil are different: the water-based solution gels, while the oil acts as a cooling bath.

A useful trial

Record how much water is present, how the fat is distributed and the texture you want. Then choose between gelling, emulsifying and making a powder, without changing every ingredient at once.