The Oxford Companion to Beer definition of
germination-kilning vessels (GKV)
are combination vessels in the malting plant that combine the last two of the three principal stages of the malting process into one. The malting stages are (1) steeping of the grain in cylindro-conical or flat-bottomed tanks to clean and hydrate it; (2) germinating the grain under temperature-controlled humidified air in rectangular or circular vessels to activate enzymes that begin the process of gum, starch, and protein modification; and (3) kilning the grain to dry it and to kill the new plant shoot (the acrospire) and rootlets that started to develop during germination. In a GKV, germination and drying occur within the same vessel without the need to transfer the green malt from a germination box to a kiln. Once germination is complete, the humidified air that was blown through the grain bed is replaced by hot dry air.
GKVs, like single-purpose germination vessels, come in rectangular or circular shapes. They need to be fitted with malt turners to keep the malt rootlets from matting together at the germination phase and to ensure proper aeration during aspiration. During germination, the turners ensure the proper rotation of the batch from top to bottom. This ensures the homogeneity of the finished malt.
GKVs tend to be completely automated. Malt turners in a rectangular GKV move back and forth through the grain bed. In a circular GKV, the floor carrying the grain may revolve instead, while the malt turners are fix-mounted and thus stationary.