Gellan
Origin - Microbial Biofermentation
Generally Use - 0.5% - 1%
Key Characteristics - Gel forming, Sensitive to Calcium.
Low Acyl Gellan - forms firm, brittle gels. High Acyl Gellan - forms soft, elastic gels.
Gellan comes in two types - High Acyl Gellan or Low Acyl Gellan, the two types can be used together to achieve the chefs desired texture.
Typically is used to form gels or fluid gels, as a stabilizer, or in very low concentrations to suspend particles or small objects (such as fruit juice spheres) in a liquid.
A gellan gel has the advantage of having quite a high melting temperature, 80C or even above. For that reason it is sometimes used for creating hot gels or as an ingredient in ice-cream or sorbets which can be flamed with alcohol.
Gelling
To gel blend gellan into cold liquid and slowly heat to a low simmer while whisking. Pour out and allow to set.
Fluid Gels
For a fluid gel either continuously blend the gellan as it cools or allow it to set into a gel then puree that gel.
Other
Gellan’s sensitivity to calcium means it can also be used for spherification with the right conditions.
Also in very low concentrations gellan can be used to suspend particles (or fruit ‘caviar’ etc) in a liquid, holding them in place in a way that seems to defy gravity. Also at low concentrations two equal gellan strength solutions can be contained in the same vestal without them mixing. Heston Blumenthal uses this effect cleverly in serving a glass of tea which is iced cold if drunk from one side of the glass but hot tea if consumed from the other side of the glass as the two temperature liquids containing gellan remain separate without any physical divider.
Keywords:Gellan, origin,gelling,fluid gels