Typically, glass bottles are created in a factory using an automated process, however, the process can be recreated at home. There are two main steps when it comes to making glass bottles. The first involves molding the molten glass using an iron mold and air. The second involves reheating and cooling the glass.
Using tongs, carefully pour a stream of molten glass into iron tubes to form the gobs that look somewhat like a short bottle with thick walls. These are called parisons.
Transfer the parison into a mold made of iron.
Using compressed air, blow air into the glass until it acquires the shape of the mold. This process is called blowing. Once it has taken shape, release it from the mold.
Once removed from the mold, make sure to anneal the bottle. Annealing is the process of reheating the glass and then gradually cooling it. This is done to remove the stresses and strains in the glass after shaping. If this is not done, the glass bottle may shatter due to the buildup of tension caused by uneven cooling. Once the bottles have cooled to room temperature, they are ready for packaging.