Researchers in Austria have developed a new three-dimensional culture system for growing mini brains in the lab. They began with a custom blend of human stem cells growing inside a spinning bioreactor, and coerced them to assemble into complex structures they call "cerebral organoids." After two months of growth, these unassuming tenderloins reached their maximum size -- one far shy of an actual human brain -- but they have persisted ten months now, and their survival appears indefinite.