GUSHING The phenomenon called "gushing" is mostly due to the properties of the product that is bottled (e.g. beer). Besides that, for carbonated mineral water, gushing can also be induced by damages or residues on the inner surfaces of the bottle. Those can lead to spontaneous release of the carbonic acid present in the product. The residues mostly consist of mineral precipitations or microbiological remainders (mould in general). To avoid gushing, it is advisable to ensure an optimal removal of mould depots and a effective stabilization of water hardness in the cleaning caustic. In general, it is a well-known fact that mostly PET-bottles are affected by gushing because their surface is softer and therefore much more susceptible to damaging than glass bottle surfaces.