Several people have pointed out that it shouldn’t be called “unsweetened” tea, but should be called “non-sweetened ” tea. The sweetness (such as sugar) wasn’t taken out of the tea—it was never added.
 
“Does it bother anyone else that it’s called ‘unsweetened tea’?  I’ve never seen anyone actually removing the sweetness from tea.  Why isn’t it ‘non-sweetened tea’?” was posted on the newsgroup hsv.general on June 7, 2000. “Unsweetened tea isn’t actually unsweetened, it’s non-sweetened” was posted on Reddit—Showerthoughts on July 5, 2019.
 
         
Google Groups: hsv.general
How do you order a soda down South?
Ron Hammon
6/7/00
(...)
> Does it bother anyone else that it’s called “unsweetened tea”?  I’ve
> never seen anyone actually removing the sweetness from tea.  Why isn’t
> it “non-sweetened tea”?
>
> Lee “anal-retentive, non-tea drinker” Seitz
>
>
Sort of like UNleaded gasoline that we once paid extra for!  They must’ve had to knock ol’ George in the head to prevent him from putting that dammned tetraethyl lead into it.
       
Twitter
Heather
@LLandscapes
@HalSparks I am so fucking thrilled someone knows his English! It should be “non-sweetened”, not “unsweetened” #Charmaggedon
2:22 AM - 24 Sep 2011
 
Twitter   
Paladin 🔰
@paladin
Why is it “unsweetened” tea? That implies it was once sweetened and then the sweetener was removed. Shouldn’t it be “non-sweetened” tea?
5:44 PM - 23 Nov 2011
 
Twitter
CJ NapIes
@cjnapIes
Shouldn’t “unsweetened” tea be referred to as “non-sweetened” tea, since it was never sweet in the first place? @GrammarMonkeys
10:22 AM - 2 Jul 2012
 
Twitter
Scott Knight
@_saknight
It should be “non-sweetened” tea, not “unsweetened.” I didn’t put sugar then take it out, just didn’t put it. #semantics #grammarnazi
7:56 PM - 27 Jun 2013
 
Twitter
Joe Wolf ☕ 🐺
@bdkosher
Why isn’t unsweetened tea called ‘non-sweetened’?
3:06 PM - 8 Sep 2014
     
Twitter
Nathan Reese
@nathanjreese
Why do places call it unsweetened tea and not non-sweetened tea? Did they remove the sugar from it with a centrifuge?
12:15 PM - 5 Sep 2018
 
Reddit—Showerthoughts
Posted by u/Ben_Driftwood July 5, 2019
Unsweetened tea isn’t actually unsweetened, it’s non-sweetened.