Soap is like a fine wine - it gets better with age.
The process we use to make our soaps is called 'cold process soap making'. Cold Process soap is made by mixing sodium hydroxide (lye) with water, then blending it with oils, then adding essential oils and natural colorants, and finally, pouring it into molds to make it nice and pretty. Of course this is a very simplified tutorial but it gives you an idea. The soaps then sit inside the mold for 24-72 hours to saponify (become soap), are removed from the mold to dry for 24 hours, then cut into single bars and must then "cure" for 4-6 weeks.
So why not use the soap after 1 week? Well, although the main process, saponification (the binding of Sodium Hydroxide/Lye and Oils), is done within 24-48hrs, there is still more chemical processes going on that would require a chemist to explain in detail. To keep it simple: water loss is the major part of the curing process as well as structural change and the drop of the ph. The recipe itself plays a huge role too. Recipes with a high Olive Oil content can take much longer - often 6 months or longer. Soaps with butters will harden quicker and be at their best after 4 weeks.
How can you as a customer know when you purchased a bar that was not fully cured? Watch out for these characteristics: the soap feels slimy when it comes in contact with water, the soap dissolves pretty quickly, the soap does not lather well, the soap is harsh to the skin.
We at Blue Bison Soapery want our customers safe and happy. We want them to leave our store with a bar of soap (or two ;)) that is not only SAFE but at its BEST. A bar that is hardened, mild to the skin, lathery, and long lasting in the shower/tub.