Baoning Vinegar（保宁醋 – Bao Ning cu – ball neeng tsoo – “Baoning vinegar”）comes from Langzhong（阆中）which is a city in Sichuan. Baoning（保宁）is an old name for Langzhong. Langzhong is famous for its “ancient city”, a large section of Langzhong designed to look like ancient China. Many Chinese tourists travel there, are there are many gift shops selling Zhang Fei beef jerky and Baoning vinegar. I couldn’t bring any vinegar back with me because it may crack and leak in the suitcase. Baoning vinegar is used a lot in Sichuanese cooking to add sour flavor. There is only one distributor of Baoning Vinegar in the USA, in Monterey Park. The only store I’ve found it in is Hawaii Supermarket in San Gabriel.
If you can’t get it, you can use Chinkiang Vinegar AKA Zhenjiang Vinegar (Chinkiang is the Taiwanese name and is more popular in the USA, while Zhenjiang is the Mandarin name), which is found in every Chinese supermarket in the USA and also internationally! The Jin Shan brand of Zhenjiang Vinegar from Jiangsu Hengshun Vinegar Industry CO, LTD. is the best Chinkiang vinegar（镇江香醋 – Zhen Jiang xiang cu – juhn dzyahng syahng tsoo – “Zhenjiang fragrant vinegar”） that is easy to find. This vinegar comes from Zhenjiang（镇江）a city in China. Don’t get the Asian Taste brand because I have heard it is not actually from Zhenjiang. Both Chinkiang and Baoning vinegars are “black vinegars”, vinegars with black colors and slightly sweet flavors. There is also a famous black vinegar from Shanxi Province and you can find it at a Chinese grocery store, but I have only used the Baoning and Chinkiang vinegars before.
My family has found out that “Balsamic Vinegar of Modena” is a great substitute. It does not taste much like Chinese black vinegar, but it pairs well with Chinese flavors in our opinion! (“Balsamic Vinegar of Modena” in the USA means that it is not the traditional kind, but derived from red wine vinegar.) However, I recommend you get Chinkiang or Baoning vinegar first for traditional flavor, then try it again another time with Balsamic vinegar. Besides, both Chinkiang and Baoning cost much less than Balsamic Vinegar of Modena. Balsamic Vinegar of Modena is exceptionally delicious in dumpling dips,
Here are some pictures of Langzhong from my visit: