Is tasting something you see a form of synesthesia? Synesthesia is often stated as "a confusion of the senses" and some of the more common forms include "seeing sounds" or associating letters or numbers with colors. There is also a very rare form of synesthesia called lexical-gustatory synesthesia where one "tastes words."

One thing I've occasionally experienced is that I'll see something and then involuntarily will taste it in my mouth. It's almost always things that are not pleasant, like carpet or copper (things I've tasted when I was a child, I don't regularly eat these things!), and more often when seeing them in large concentrations (e.g. a particularly shaggy carpet, lots of bare copper). Like tasting food, I seem to become acclimated to it pretty quickly. 

The closest thing I've heard from other people is they'll say that food "looks so good I can taste it" or something like that. However, I usually hear this for food that also smells very good and as I understand this tasting is because smell and taste are linked (which is normal, not synesthesia). However, I experience this tasting with things that don't have any noticeable smell.

I'm not looking for a diagnosis, but I'd like to know if tasting something you see as I have experienced is something that could possibly fall under the category of synesthesia (or if there is a more mundane explanation).
After a fair amount of research, I came across Noam Sagiv, PhD, a professor at the Centre for Cognition and Neuroimaging who has done research into synesthesia, including visual-gustatory synesthesia (the proper term for seeing-tasting synesthesia). I contacted him about this and he said the following (reproduced with permission):


  I can understand your frustration with finding information about this.
  As you probably know already from trying to look up information on
  synaesthesia, there is a lot more research on coloured letters and
  numbers than anything else.  
  
  There are a few types of synaesthesia
  where taste is the inducer (e.g., coloured taste) and a few that
  involve taste as the synaesthetic experience: For example, musical
  notes/intervals > taste, or lexical > gustatory that you mentioned
  already.
  
  In our experience there are also two other variants; there are no
  published papers yet that I am aware of but we recently accepted an
  invitation to write one.   
  
  1) We tentatively
  labelled it mirror-taste synaesthesia - this is where you see someone
  else eating something (with no smell - e.g., on TV) and experience a
  flavour experience that mirrors the other person's - i.e., similar
  principle to "mirror touch" synaesthesia, where you see someone being
  touched, and feel the same experience on your own body. The "social"
  aspect here is critical - it's not enough to see the food, you need to
  see another person eating it. My conference presentations covered this
  one - particularly a brain imaging study we conducted, where we found
  that basically, we all do something similar, even if only a minority
  of individuals actually experience it: What we found is very simple,
  that videos of people eating activate not only the visual cortex
  (which is what everyone expects) but also the gustatory cortex,
  despite the absence of direct stimulation of the sense of taste.  
  
  2) The other type of gustatory-visual synaesthesia we would like to
  start exploring soon, is the more direct type you describe. You see
  something that you've tasted before, and experience the taste
  involuntarily/automatically and vividly. We have a couple of anecdotal
  cases but haven't started the formal survey. I expect this to be more
  common with foods than with non-edible things, but the fact that you
  get this for some early experiences is consistent with findings from
  gustatory lexical synaesthesia (where the synaesthetic taste
  "repertoire" includes things you've eaten as a child, even if you
  haven't had those for 30 years, and doesn't include things you eat
  often now, but haven't tried as a child; these things probably
  consolidate in the first decade of life, probably first half).   
  
  We
  often find we learn new things from synaesthetes and enquiries like
  yours. I'd be grateful if you did participate in our forthcoming
  survey, and/or other studies in the lab if you are in the area (West
  London, UK).


So the short answer from a leading expert in the field is: this area has not been extensively researched, but tasting something you see does indeed seem to be a form of synesthesia, possibly including the situation that I described in the question above.

Dr. Sagiv has also extended the invitation to participate in research on synesthesia to everyone here on CogSci Stack Exchange, so feel free to contact him to discuss any synaesthetic experiences, volunteer to participate in a survey, and/or go to his lab in West London.