Longer answer - all smellable scents are composed of chemicals that our scent receptors can understand, primarily by having the chemical compounds actually arrive into our noses and touch the receptors. What that means is that a fart is composed of very fine “shit particles” that float about till they enter your nose and cause you to smell it.
While an individual fart may be difficult or impossible to bottle, since it contains very few particles needed to either store or replicate successfully, the existence of fart candles displays that farts can be emulated by scent manufacturers by studying the chemical composition of farts.
I wonder how many farts it would have taken for scent manufacturers to successfully replicate a particularly pungent fart!