Fuente: WIPO "meat" A method of forming a hydrogel fibre inside a bioreactor is provided. The method comprises steps of providing a container vessel of the bioreactor with a volume of cross-linking fluid therein, and injecting a flow of hydrogel precursor fluid into the cross-linking fluid, whereby the hydrogel fibre is formed, wherein a leading end of the hydrogel fibre revolves at least partially around a vertical axis, in particular a centreline of the container vessel. Bioreactors and bioreactor assemblies for cultivating fat are also provided. The hydrogel fibre is preferably formed from a cell-containing hydrogel precursor fluid comprising proliferated cells, in particular fibro-adipogenic progenitors, in particular of mammalian origin, such as of bovine origin.