While enjoying your favorite beverage, you may wonder how beer bottles are made. They come into the world through relatively universal factory method used to make most types of bottles. Many, if not most beer bottles are made of brown glass. This is because the brown color was thought to help keep out the damages of the sun’s rays on the beer inside. No matter what color, beer bottles are made by the same factory process.
- The raw materials to make glass are melted and mixed in a furnace over the span of a day. These ingredients include silica sand, soda ash, limestone and varying amounts of recycled glass pellets called cullet. According to "How It’s Made," the furnace is kept at 2,730° forming molten glass. If the bottle is to be brown, small amounts of iron, sulfur and other chemicals are added for color.
- The molten glass is dripped from the furnace and cut by machine shears at exact measurements. The molten gobs are then moved by a machine scoops into troughs to be shuttled to the next part of the beer bottle making process.
- Next the gobs are poured into small molds. Miniature beer bottles, usually less than half their final size are created here. The mini bottles are solid molten glass.
- The little bottles now travel to the next mold, or “blow mold”. Here, the molten glass forms are dropped into another mold that is the size of the completed beer bottle. Compressed air is then forced down into the small bottle top, blowing the molten glass out until it reaches the sides of the larger mold. In this way the process is very similar to traditional glass blowing. The glass is simply blown out to create the final size and the hollow interior. If any numbers or symbols are needed on the final bottles they will be craved into the walls of the final mold.
- Finally, the bottles need to be cooled in a controlled way. If they cool too quickly the stress will create weaknesses and even fractures in the glass. The bottles are usually cooled on large automated racks aided by computer driven fans. Some factories lubricate the bottles so they will have an easier time traveling through the final stages of quality checks and label additions.