Does anyone know how old this bottle may be?
It is irregularly shaped, it has no prints and is +/- 60 cm high.
Thanks a lot in advance!
It's impossible to pin down the age of the bottle without more information and/or images.
From what I can see in the two images, this "fermenter" likely to date to the last quarter of the 19th Century, but that's just an educated guess based on decades of collecting demijohns and carboys. The bottle below (another fermenter) is about 46 cm tall, blown in a 2-piece mold, has an applied lip, and has a "sand" pontil scar. Not American, origin uncertain.
Right, you could say 19th century in general but getting more specific would require a few more photos....close up of the lip / neck, and a photo of the base. Even then, it may still be difficult to tell.