Bloom

Chocolate must be tempered to stabilise it before use, or crystals may form on the surface of chocolate, causing what is known as 'bloom'. This can appear as a white film on the surface of chocolate, and in some cases the chocolate may become soft or crumbly.

There are two kinds of bloom that form on the surface of chocolate:

• Fat bloom (where the chocolate loses its gloss, developing a powdery grey-white film on the surface), and due to improper storage, poorly tempering, lack of tempering, or changes in temperature.
• Sugar bloom (where a dull white film forms on the surface of the chocolate, usually dry and hard to the touch, and the chocolate becomes soft or crumbly), due to repetitive heating and cooling or cold storage.

Whilst bloom diminishes the appearance of the chocolate, it is not harmful and does not alter the taste.

See also Fat Bloom and Sugar Bloom.