Metallic taste in gazpacho

Droplet, I'm exactly the same. For some reason, my mother and I are unable to eat any seafood/fish with either tomato or cucumber (or both) - they leave a foul taste in my mouth and it's liking I'm eating food that has gone off even if it's fresh. In contrast, this problem doesn't seem to occur when the tomato is cooked.

So interesting. Thanks for all the great input. I'll have to try a batch without seeds and see what happens. It's fascinating how dramatically different our palates are; I cannot taste the metallic thing at all, even when I try, and my partner gets the taste on contact and can't shake it from his mouth afterward.

According to Chris Kimball, the seeds in tomatoes have 3X more flavor than the flesh! (http://www.eatyourbooks.com/blog/2012/10/17/for-maximum-flavor,-stop-seeding-tomatoes) Sounds like pulverizing may be the villain here. I use a simple food processor, and never noticed this, but try low tech and some judicious paring per Sam. Interesting clues from droplet -- has he ever had a similar experience?

Vvvanessa, I've experienced the same thing when being served cooked fish with uncooked tomatoes (say a grilled or roasted mackarel with fresh tomato salad). Each by itself tastes great but combining them in a mouthful leaves a terrible taste on my palate. I thought it was just me, but when I have asked other people, I've gotten poitive answers from some of them too. So I guess it is similar to the known cilantro phenomenon. The way it ties to your case in my mind is that olive oil, from a chemical perspective (and taste too) relates closely to the fat composition of fish fats. That is especially true if you take a robust first pressing extra virgin. I have no clue what you used, but if it was one of those, that's probably what did it once you combined them in a blender. My second guess would be a cucumber that has a bitter-ish end which got in there.

Just cut them in wedges, and use a spoon to scrape out the seeds; you could press the pulp through a strainer with the back of a spoon to save more of the liquid bits you scoop out with the seeds---leaving the seeds behind and saving the juice and pulp. Discard the rib bits.
For the cukes..do the same, or use "English" cucumbers. The core of the tomato can be bitter also..so use a paring knife to scoop out the top stem part..and trim off the 'ribs' when you slice and process. The big stem part (Upper and lower) of a tomato is especially bitter if you just toss a whole one in a vitamix. Look for a something called a 'tomato shark' to help scoop and remove those.

More...intact seeds might not be detected on the pallet for slices of tomatoes/cucumbers...but releasing chemicals in the seeds with the pulverizing--could throw off the flavor for a super taster. Same with Apple seeds which is far more pronounced if you have a slice with the seeds..same with grapes with seeds.

Ahh..did you use the seeds in the vitamix? Those can make a bitter taste which I would suppose someone could describe as a metallic. The vitamix would pulverize those into the soup, same with the cucumber seeds.

Did you use an aluminum pan, or strainer/food mill to make the soup....or any aluminum that contacted the soup. The high acids in Tomatoes will react with aluminum and give it a metallic taste...or discolor the product.

Those are all great thoughts, though I don't think any of them is actually responsible for the taste he's getting. I think his tastebuds are just being wacky. Thank you for your thoughtful answers!

In addition to the above suggestions, if you mixed (or stored/served) the guac in a metal bowl that can occasionally provoke a slightly tinny taste.

This is curious. Is there a possibility the olive oil was rancid? There's also a strange phenomenon known as "pine mouth". I've had it and it taints everything you taste for up to 2 weeks with a metallic flavor. It's associated with pine nuts. Good luck! Perhaps he'll taste the gazpacho tonight and it will be delicious. Here's hoping!

http://www.fda.gov/Food/ResourcesForYou/Consumers/ucm247099.htm

The metallic taste could be coming from some medication or vitamin he may be taking which can come out when eating.