Rim a Collins glass with hibiscus salt and sugar. Combine all of the ingredients except the soda in an ice-filled shaker. Shake and then strain over ice into the glass. Top with grapefruit soda.
Hibiscus Syrup: Once the simple syrup is created, soak hibiscus teabags for approximately 15 minutes in hot simple syrup, adjusting time based on taste. Soaking longer will give it a stronger taste and richer color. The syrup is good for up to two weeks.
Hibiscus Salt and Sugar: Mix equal parts coarse sugar and coarse salt with a pinch of dried crushed hibiscus. Adjusting for preference.
