4 months old the beer is it safe to drink?

* Beer is a living product: It contains yeast and bacteria that continue to work even after bottling. These microorganisms will continue to ferment and change the beer's flavor over time.

* Flavor deterioration: While some beers improve with aging, most beers will start to deteriorate after a few months. This will result in off-flavors and a less pleasant drinking experience.

* Spoilage: If the beer is not properly stored, it can become contaminated with bacteria or mold, making it unsafe to drink.

General guidelines for beer storage:

* Most beers: Enjoy within 6 months of purchase.

* Lagers: Best within 3-6 months.

* Ales: Best within 6-12 months.

* Stouts and porters: Can age for several years (especially if bottled).

Important Note: Always check the "best by" date on the bottle or can. This is a guideline from the manufacturer for the optimal drinking experience.