Side by side, trying one after the other. I can tell they taste different. But walking into a place blind, and only getting one. I think it might be hard to tell.

Taste-wise? Probably not. But I'd know by 11am because the caffeine withdrawal would start and I'd get headaches.

I'm a pretty avid coffee enjoyer, and I can't tell the difference. The stuff that you can buy chemically decaffeinated are made by brands that generally sell lower quality coffee beans in the first place

Only if you're sensitive to caffeine.

My sister would feel the difference because her heart goes nuts if she has regular coffee. I wouldn't since I'm an addict with high tolerance. Maybe the headache around noon would make me suspicious but probably not.

Side by side I could pick out bad decaf, but I'd struggle to notice good decaf.

On its own I'd just assume I was given a bad to average cup of coffee, which is what I would expect anywhere but home.

At a cheap diner? You'd have a hard time telling cuz even when you use regular coffee, the caffeine content is pretty low.

Anon says it was a restaurant that happens to serve coffee; not a dedicated coffee shop. So, honestly, probably not. Chances are the coffee would be stale, burned, or just plain poorly brewed regardless of what beans were actually used.

A lot of whining is done about decaf, but it takes a pretty refined palate and a lot of experience consciously tasting the differences to be able to reliably tell the difference by taste alone.

The biggest giveaway is the near total lack of a caffeine buzz, even after several cups. But the placebo effect will go a long way to mitigate that.

Depends on the coffee.

I developed a sensitivity to caffeine, it basically throws me into a weird heart racing thing at any but the smallest doses.

But I freaking love coffee. So I buy decaf. If you shop around, find a few brands that do water process decaf, you'll end up with something that's good. Not just good enough, but good.

But the chemical process decaf, yeah, I can tell a difference blindfolded. Literally, I won a bet doing it.

The typical name brands, they usually have a fairly over processed taste to begin with. So it's harder to detect, and I can't tell the difference as clearly. It's there, but you have to already have compared them before you can tell blind.

Thing is, part of that is how you drink coffee. If you're drinking it out of habit, or on the go, your brain is going to filter the taste out in favor of other sensory input. You have to be drinking it for the coffee itself, paying attention to the experience.

Chemical process decaf has this layer of unpleasant metallic tang to me. Water process tastes like the same basic roast and bean, just slightly less intense. Things like floral notes get a little muted.

You don't expect good coffee in restaurants, and it's hard to tell between bad coffee and bad decaff

At least the ones i have tasted decaf espresso does taste more weak but might have been because my decaf beans were noticeably older and the freshness seems to be one of the biggest factors. If i took decaf coffee somewhere based on my knowledge i would likely just assume that it is old/low quality/not brewed strong enough before i would assume its decaf

I don't drink coffee, but shouldn't that be the case everywhere, cause of the extra steps you have to take to remove the caffeine from the beans?

Also I've never been charged for a coffee refill.

Coffee is usually free after you buy the first cup.