Does Sesame oil density change after the container has been opened for several days?

Marginally. Butterfat can separate or bloom, but measured weight per cup/mL stays within 1 % as long as the product is within its use-by date.

Can I swap whole Sesame oil for skim at the same gram weight?

For mass yes, but fat content changes flavor, browning and texture. In baking, match the variant the recipe expects rather than the raw gram count.

By Fidamen-Chefsolver Team | Reviewed by Chefsolver Staff

Sesame oil; aromatic oil with nutty, toasty notes.

Ingredient

Use as a finishing oil or in dressings; add near the end of cooking to protect flavor.

Does Sesame oil density change after the container has been opened for several days?: Marginally. Butterfat can separate or bloom, but measured weight per cup/mL stays within 1 % as long as the product is within its use-by date.
Can I swap whole Sesame oil for skim at the same gram weight?: For mass yes, but fat content changes flavor, browning and texture. In baking, match the variant the recipe expects rather than the raw gram count.