The density and amount of bubbles that your bar of soap makes is sometimes refereed to as the lather. The lather of soap can have a variety of properties and the amount or size of the bubbles can be affected by the ingredients in the bar and the type of oils used.
For greater bubbles that are big and fluffy add more coconut or castor oil. For smaller more dense bubbles add more heavy butters like shea butter and cocoa butter. Additionally additives can dampen the effect of later like goat’s milk or clay, while some additives like sugar, beer, and wine can boost the effects of later.