There is one restaurant here in Liuzhou which claims its 卤水 (lǔ shuǐ) is over 70 years old.
By the way, the article linked to says the Chinese is 'lou mei'. It may be in some obscure dialect, but in Mandarin, spoken by the vast majority, it is lǔ shuǐ (pronounced roughly like 'loo shway'). Several sites claim this means 'old water'; wrong! It just means 'master stock' and the etymology is 'brine water'. No mention of its age.