Unlabelled - The spikes of gramineous plants are composed of specialized units called spikelets. Two bracts at the spikelet bases are known as glumes. The spikelet glumes in barley are degenerated into threadlike structures. Here, we report a long glume mutant, , similar in appearance to a lemma with a long awn at the apex. Map-based cloning showed that the mutant allele has an approximate 1.27 Mb deletion of in chromosome 2H. The deleted segment contains five putative high-confidence genes, among which HORVU.MOREX.r3.2HG0170820 encodes a CH zinc finger protein, an ortholog of rice and an important candidate for the allele. Line GA01 with a long glume and short awn was obtained in progenies of crosses involving the mutant. Interestingly, , a mutant with long glumes on lateral spikelets, was obtained in the progenies of the mutant. The long glume variant increased the weight of kernels in the lateral spikelets and increased kernel uniformity across the entire spike, greatly improving the potential of six-rowed barley for malting. Supplementary information - The online version contains supplementary material available at 10.1007/s11032-024-01448-x.