1/2 cup pineapple juice (or juice from canned pineapple)
1/4 cup white vinegar
1/4 cup ketchup
1/4 cup sugar (adjust to taste)
1 tablespoon soy sauce (optional)
1 teaspoon grated garlic (or 1/2 teaspoon garlic powder)
1 teaspoon grated ginger (or 1/2 teaspoon ginger powder)
1 tablespoon cornstarch
2 tablespoons cold water
Pinch of salt (optional)
In a small saucepan, whisk pineapple juice, vinegar, ketchup, sugar, soy sauce (if using), garlic, ginger, and salt.
Bring to a gentle simmer over medium heat.
In a small bowl, mix cornstarch and cold water until smooth.
Slowly whisk cornstarch mixture into the simmering sauce.
Simmer 1–2 minutes, whisking, until thickened and glossy.
Taste and adjust sweetness or tang (add more sugar or vinegar as needed).
Remove from heat and serve warm or cool to thicken further.