Where the oils and the lye come from

The first supply decisions, and the ones that quietly set your consistency.

Two different purchases

Oils are a perishable agricultural product with lot-to-lot variation.

Lye is a chemical of stated purity that does not vary and does need care in shipping and storage.

Buying both from the same place is convenient and rarely optimal.

Oils

Start with the grocery store: olive, coconut and castor are all available and make excellent soap.

Move to a soap supplier when volume makes it cheaper, which happens sooner than expected because supermarket oil is packaged for kitchens.

Buy fresh and buy what you will use, since an oil sitting half-used for a year is where dreaded orange spots come from.

And when you settle on a recipe, settle on a supplier too: a different origin of the same oil has a slightly different SAP value and a slightly different bar.

Lye

Sodium hydroxide, 100% pure, no additives. Drain cleaner is not a substitute unless it states pure sodium hydroxide, and most do not.

Buy from a soap supplier or a chemical supplier who ships it routinely, since it is regulated in transport.

Ask for the safety data sheet with the first order and keep it where you work, not in an inbox.

Store sealed, dry, labeled, and somewhere a child or a guest cannot reach. It absorbs water from the air and degrades if left open, which also makes your lye calculation wrong.

Keeping the lot numbers

Write down the supplier and lot for every oil, the lye lot, and the fragrance lot, against the batch number.

It takes a minute and it is the only way to explain a batch that went wrong six weeks later.

It is also what a wholesale buyer and an insurer expect a manufacturer to have.

References