Are most stouts caffeinated?

[Brewer #441850]

Are most stouts caffeinated? Google says not all are, but I can’t figure out a way to tell if ones I’m looking at the store are caffeinated or not. I’ve avoided the style until recently, and I can’t find it listed on the bottles, at least not the few I’ve tried.

 

[Minbari]

If they are a coffee stout, sure. But i don't think anyone adds caffeine

 

[Semper Sitientum]

^ This. Plus, if flavored with chocolate it will have some caffeine, albeit a very low amount.

 

[Donoroto]

So “most” stouts are not. Some are. Non are very caffeinated, maybe like a cup of coffee per gallon at most? Pure speculation, but sounds right.