Created in 1868 by New Orleans banker Edmund McIlhenny, Tabasco has grown from its New Orleans roots to become the ubiquitous American hot sauce. Also branching into foreign markets, Tabasco is sold in more than 160 countries around the world. Tabasco is known to last, opened or unopened, refrigerated or unrefrigerated, for years. Enduring though it may be, the many different Tabasco sauces do eventually expire. The product won't spoil and become unsafe to use, but it might not taste as it should.
Look at the date code on your Tabasco bottle. Each Tabasco bottle is marked with a date code to identify its production date. The first four numbers identify the day and month, so 0512 would mean May 12. The fifth number is the year code, such as a 14 for 2014. So, if you see 051215, it means it was produced on May 12, 2014.
Check the type of Tabasco you have. The different varieties of Tabasco have different shelf lives. The original Tabasco sauce has a shelf life of five years, while Tabasco Garlic Pepper and Habanero sauces last two years and Green Jalapeno Pepper and Chipotle Pepper have just 18 months of usefulness.
Compare the date code on the bottle against the shelf life of the sauce. Open or unopened, Tabasco sauce shelf lives are the same. If the time since the production of your sauce extends beyond shelf life for the sauce, it has expired.