Relativity in culinary matters and in taste is a big issue - our tastes (or distastes) for things are indeed shaped by what we are used to eat and see eaten, as well as other factors, genetics being one. Now they combine with less strictly sensorial aspects - and disgust for instance integrates, as Rozin pointed out, what he calls "cognitive aspects" such as the idea that substance X is contaminating. 

In his reply to Nicolas Baumard' post "Is a universal Michelin guide possible?", Jonathan Mair raises some interesting questions about "culinary relativism". The first idea is that there is no room for relativism once foods, ingredients and recipes circulate : " Relativism really requires sealed units (culture) within which everything is familiar and between which many things are completely unfamiliar. Most people are faced with a whole range of degrees of exposure to different unfamiliar foods"  The other has to do with possible differences in perceptions, revealed by linguistic differences : "As an English speaker I think of spicy things as being hot, obviously not the same hot as boiling water, but not altogether different either, and if something is too hot it burns no matter which kind of hot it is. I was surprised to find out this doesn't work in many languages - spicy things are itching or stinging in Spanish for example (possibly a bad translation, in any case, they're not hot and I don't think they burn). In Chinese there's also a completely different word for 'hot hot' (re, tang) and 'spicy hot' (la). But, in Mongolian (which was my fieldwork language) there is one word for both (haluun) just as there is in English."

Maybe I am missing something, but I don't see why relativism, either concerning sensation and perception, or concerning the more cultural aspects of food preparations and culinary principles, couldn't apply in groups that are "open" and when foods available more widely.

Well, spices stimulate the trigeminal nerve (the one that runs through your face, thus the fact that you get red, cry, and feel a burning sensation over your nose when you eat chili or mustard). It is thus a tactile and pain sensation, which of course gets bound with the tastes and smells one experiences at the same time (this binding is very complex, and what you feel trigeminally may influence your overall flavour perception, or be influenced by other dimensions of the food experience). Both thermal, textural and pain information is conveyed through the trigeminal pathways - and being then classified as hot or itchy. Thus these two words may well target the same bundle of sensations - menthol is reported to be cold, fresh, and slightly irritating, for instance. So, one has to be careful NOT to say that people don't experience spices being hot just because they do not call them "hot". Interestingly, one of the most frequent adjectives for spices is "burning" - which combines the thermal aspect (hot) and the pain aspect (irritating).  

Now if the qualities or dimensions of what is experienced may not differ, the intensity of the burning-hot-irritating aspect raises problems, that Jonathan's remarks underline. Suppose the two Chinese words, the one meaning 'hot hot' (re, tang) and the other meaning 'spicy hot' (la) both apply to food. Do chinese speakers, with similar culinary background, disagree on whether one and the same (token) dish is 'hot hot' or 'spicy hot', and what happens if you add some capsaicin (the "active" part of chili) to this very same dish, while keeping the other ingredients untouched? Although the two terms may target either a qualitative difference between two kinds of trigeminal pattern of stimulation, they may also reveal a difference in intensity within the same pattern (or both an intensity and a quality differentce ? cooking is a such melting-pot...). Still, the idea that they refer to an intensity difference would explain the single word in English and Mongolian : every spicy food burns a lot, because members of these communities are not used to eat spices. Chinese are  used to some degree of trigeminal irritation (spicy hot) which doesn't mean they are insensitive to irritation, and some dishes are still 'hot hot'. But this is just a guess - and it should be checked.   

The intensity of the trigeminal sensation varies with exposure, and this is well studied, for example in this paper : " In humans, repetitive application of capsaicin, citric acid, or concentrated NaCl elicits oral irritation that grows in intensity across trials (“sensitization”). After a rest period, reapplication elicits less irritation (“self-desensitization”), but if given recurrently will eventually evoke a progressive rise in irritation (“stimulus-induced recovery”). In neurophysiological recordings from neurons in the trigeminal subnucleus caudalis (Vc), the first relay in the pathway for oral somatosensation, these irritants elicit a similar pattern of progressively increasing firing, followed after a rest by self-desensitization and “stimulus-induced recovery”. In contrast, nicotine, menthol or mustard oil elicit irritation that decreases across trials (“desensitization”), a pattern also observed in Vc neuronal responses to these irritants"

Reading this paper, I realise that actually, Coca-Cola may be closer in some respects to spices. It irritates. But now, I would have to say the same thing about Champagne - but really, being French, I can't but think that Champagne must be an exception !