Place the red cabbage on paper towels. Sprinkle with salt. Let stand 3 hours. Pat cabbage dry. Set aside.
Place pickling spice in a piece of cheesecloth or a coffee filter and tie securely with cooking twine. Place the vinegar and the spice pouch in a large saucepan. Bring to a boil; reduce heat to medium and cook for 5 minutes. Discard the spice pouch. Let vinegar mixture cool to room temperature.
Pack the cabbage into clean, hot jars and pour the vinegar mixture over them. If necessary, add additional malt vinegar to completely cover.
Seal the jars and store them for at least 1 week before eating.