I am going to cover a bit more about objective vs subjective in the next article along with the physical and psychological aspects of taste and smell and memory. It's a very fascinating subject. :)

No, nothing wrong with how people write their flavor reviews as it is how they want to write them. The "delicate sensory tickling" was actually on a forum not reddit. :) I spend a lot more time on FB, and that is where a lot of the clone requests and people not able to describe what they are looking for is. I see a lot of people on here using the flavoring language and it is quite nice to see.

I put the wheels up there for folks to print out if they wanted to. When you click on them it will open full page picture, they are larger sized pictures when you're on a computer. I printed them out and have them in clear binder page holders so I won't spill on them -- cause I spill everything. lol Printed on full page paper they are readable.

Your English and grammar is good enough that I wouldn't be able to tell you weren't a native speaker. So definitions for the words are:

• tart:

    1. agreeably sharp or acid to the taste 
    2. marked by a biting, acrimonious, or cutting quality 
    3. sharp, sharp-tasting that is, bitter, acid or acidic, harsh, sour taste, just like a lemon.
  

• sour:

    1. causing or characterized by the one of the four basic taste sensations that is produced chiefly by acids
    2. having the acid taste or smell of or as if of fermentation :  turned <sour milk> :  of or relating to fermentation
    3. Sour is one of the basic tastes. It is acid, lemon-like or vinegary, tart, bitter, acerbic. Sour food has a sharp
  

biting taste and, certainly, is not sweet.

The four basic flavors the definition mentions are Sweet, Salty, Sour, and Bitter.

I would say straight sour is more of a vinegar or milk that is going bad. Sweet and sour sauce in Asian food is a mixture of sweet syrup and a sour acid (vinegar). For the dairy category I'd use sour cream as an example for sour. In flavoring TFA Greek Yogurt as an example has a sour note to it similar to a dairy sour.

Tart is a subset of sour and I would mostly use it to describe more of a fruity sourness. Lemons and limes are tart. Citric Acid is very tart and sour. A green apple has a tart sourness to it. In food I think of tart as a mouthfeel along with the flavor of sour. But that's how I would personally describe it. I'm curious if others would agree.

Damn thinking about that and typing it out made me realize how correct OP is that I lack the right words to describe flavors. Very interested to read more of these articles.

I was able to find one article that discussed chemical reactions between flavorings-- I actually answered this exact question on fb as well:

"One example of a somewhat tricky flavor is cherry, mainly composed of benzaldehyde. It can react with alcohol or organic compounds within other flavors, to form acetals. Cherry is a popular flavor blended into juices and fruit punch, and Grover indicates some end-users prefer to mix their own flavors from different sources to maintain a proprietary position on their formula. However, if one company uses propylene glycol as a flavor carrier for strawberry and mixes this with a cherry flavor, this can spur a reaction over time."

Quote from this article : http://www.naturalproductsinsider.com/Articles/2003/04/New-Frontiers-in-Flavor------Interactions.aspx

Not all flavors interact to create new components, but the flavors do interact with the base that they are in as higher entropy is achieved and the equilibrium of the mixture becomes balanced.

Another aspect is most likely decomposition. The flavoring molecules do decompose and break down over time as well.

I wish I had a GC/MS machine...I'd be all over that thing if I had the money for it. I'm totally a data junkie nerd. lol If I find any more information, which is not easy to source as a lot of this stuff is closely guarded by the flavor/aroma industry. But sometimes I can get google to cooperate and I find some little gems of info. I find all of it totally fascinating and want to learn more. I've read all the flavorist textbooks that were linked to from the other subreddit, but it's still not enough -- and I can't justifiably spend $500 on a textbook at this point. It's too bad there aren't any retired flavorists who could impart their knowledge on us self taught flavor addicts. :)

Yes bot, this post is asking where to get supplies.