South Carolina's Home-Based Food Production Law (SC Code § 44-1-143) applies exclusively to nonpotentially hazardous foods — the formal term for what most people call "shelf-stable." These are foods that can sit safely at room temperature for extended periods without becoming dangerous to eat.
The science behind this definition comes from the 2009 FDA Food Code, which South Carolina has adopted as its standard. A food is considered shelf-stable — and therefore eligible for home production and sale — when it meets at least one of two conditions: its acidity (pH) is low enough to prevent dangerous bacterial growth, or its moisture level (water activity, Aw) is low enough to do the same. Most home-baked goods, jams, dry spices, and candies meet these criteria naturally.
When a product's pH and water activity fall into a middle zone — not clearly safe on either measure alone — South Carolina requires a Product Assessment (PA) conducted against the 2009 FDA Food Code standards before the product can be legally sold. Clemson University's Food2Market program is the go-to resource for this testing in South Carolina.