The process in which old or stressed yeast cells rupture and spill their contents into fermenting or finished beer. Autolysis produces several glutamate-related flavors often described as "meaty", "soy sauce" or "brothy". Autolysis is most often found in stronger, aged beer, especially with ample yeast left in the bottle, or subjected to higher temperatures and related refermentation. Strong beer, not protected by lactobacillus or other potent preservative element, and aged more than 10 years very often will show some signs of autolysis.