Soda Bottles

At the grocery store yesterday, my daughter asked me why soda bottles have the bumps at the bottom. Anyone know ?


IIRC it’s to provide more rigidity along the bottom of the bottle, which, I presume was the case even when they put the extra black cap on the bottom, to keep it looking nicer. Of course, taking the black cap off lowered the cost of producing the bottles.

Well, there are some positives to the shape. Curves are stronger than flat surfaces so this allows thinner plastic to be used. The layout of the 5 bumps (I have two Coco Cola product 2 Liter bottles here) allows decent stacking. The cap fits fairly well in the middle of the five bumps.