  This fluid dynamics video reports how to form liquid core capsules having a
thin hydrogel elastic membrane named liquid pearls. These fish-egg like
structures are initially made of a millimetric liquid drop, aqueous or not,
coated with an aqueous liquid film containing sodium alginate that gels once
the double drop enters a calcium chloride bath. The creation of such pearls
with micrometer thick membrane requires to suppress mixing until gelling takes
place. Here, we show that superimposing a two dimensional surfactant
precipitation at the interface confers a transient rigidity that can damp the
shear induced instability at impact. Based on this, pearls containing almost
any type of liquids can be created. The video focuses on the dynamics of the
entry of the compound drop into the gelling bath.
