Cut the pork in half lengthwise and then cut it crosswise into 2 1/2-inch chunks.
In a medium saucepan, bring the ber vinegar, water, garlic, ginger, salt, black pepper, and red pepper to a boil over medium-high heat. Add the pork, cover and reduce heat to low. Simmer for 1 hour, or until the pork is very tender.
Remove the pork from the liquid and transfer to a cutting board. Use two forks to shred the pork.
Using a slotted spoon, scoop out and discard the garlic and ginger. Add the shredded pork and chili sauce to the pan. Stir to combine.
Gluten-Free Adaptable: use 1 1/2 cups chicken or vegetable stock in place of the beer. Substitute gluten-free sweet chili sauce.