I've got a couple of jars of coconut oil- organic, extra virgin, in a glass jar, etc etc $$$ from Whole Foods. I took them on a trip across the country (2 weeks, living out of a car during the summer) and I can't bring myself to eat any of it. It has a strong chemical smell, grainy texture and leaves my throat feeling sore if I eat any of it straight. I've been using it as moisturizer and massage oil because I don't want to just throw it out. The smell still bothers me even using it for this purpose.
I'm wondering if its the brand, if coconut oil can actually go bad, or if the problems are due to the temperature changes from being at high altitude (and low temperature) in Wyoming to the trunk of the car in Texas at 114 degrees F.
The grainy texture is not a concern--that happens sometimes and the level varies from brand to brand. Usually the "grains" will melt when heated or rubbed on your body. However, the bad smell is definitely a concern. Did it smell normal before your trip? Or did you notice it when you first opened it. If it was there from the first time you opened it, it could just be the brand you bought.
Some of the brands are much more highly processed. The first jar I bought was Spectrum brand (I think) and it didn't really smell like coconut which I found disconcerting, but when I switched to Nutiva I got the coconut smell I was expecting. That's the brand I use now. Tropical Traditions is another brand I've heard recommended quite highly although I've never used it.
However, if the oil smelled normal before you left and now smells bad I would not continue to use it--even on my body. Coconut oil is very shelf stable and not prone to becoming rancid. Nevertheless, if the smell changed I would stop using it.
Oils can become rancid. I purchased a $$ jar of coconut oil from Whole Foods and was very hesitant to throw it out given the cost, but every time I cooked with it and put it in smoothies it was horrible. After getting another brand, I had no problem.
You bring up another issue that may not be related to spoiled oil...Pay attention to how your throat feels if you try another brand/jar that is presumably not rancid, as a sore throat is often a sign of a serious allergic reaction. Coconuts are in the tree nut family, so if you have any tree nut sensitivity you may need to stay away from coconut as well.
Coconut oil does not naturally have a smell. If you are purchasing coconut oil and it has a coconut smell, it must have some additives and is not 100% coconut oil. If it smells really bad, it is rancid. Yes, the temperatures in the car (if it is hot) can definitely turn it rancid.
There are many ways company's make coconut oil. Some use the fermentation method, which I have tried and the coconut oil does not smell or taste good. There is the method of drying the coconut over smoke (copra) and then extracting the oil which is also another common method overseas, which would make it smell absolutely disgusting(like smoke/bbq) and the color of the oil would be yellowish/greyish if not refined/bleached(I've bought this before but for other purposes). Alot of companies take the copra(dried coconut) and use solvents to extract the oil(it might be the case with your coconut oil). The best coconut oil that I use to eat and put on my skin, is from brands like "Nutiva", "Organika", and ("Garden of Life" uses Fermentation but tastes good). I have read Nutiva's website and they do say that they use a process that inhibits fermentation. In my opinion, you should'nt eat the oil you have now, try and use it up for another purpose (or try returning it), and buy a good brand of coconut oil to eat/cook with. My hunch tells me that the oil smelled like that when you bought it. I hope this helps.
it's also possible that the oil was already rancid when you bought it. (it's seems clear to me, from your description, and my experience-- that your jars were rancid). rancidity has been explained perfectly above. if processing wrecked it that badly, the store wouldn't sell enough of it to make money.
coconut oil is expensive, has a long shelf life, and is volatile to temp, time and light. stores can easily miss product that has gone bad on the shelf, the use by date doesn't tell the complete story.
i work for a boutique grocery that is a competitor to Whole Foods; i'm known as the "answer lady" in that store. i can tell you that when stores receive their loads, the groceries haven't always been held at temp properly on the trucks, esp.in the summer. it's our job to refuse the shipment, or write off bad product as a loss. that said...
while it's very easy to see that the shipment of fresh raspberries are bad because they grow mold in a New York minute, we are not opening jars of oil to see it they are okay. problems like that are so rare it's not worth our time. also, even after being abused, the oil still takes a little while to spoil. i once saw 144 jars of coconut oil arrive clear, and take an hour or so on the shelf to solidify...clearly it wasn't staying cool enough on the truck. this rarely happens, and we catch it when we can, but there is always stuff we can't catch, and we take returns with a smile, and we apologize. if happens often we discontinue our relationship with that supplier...
it's always a good idea to test a perishable before you take it on a trip, or in any situation where you are depending on it and you can't replace it. that way you can return it right then. don't open it until after you have paid for it though - because if it's open, by health code, the store can't sell it to you.
it is also possible that it became rancid on "your truck" instead of the shelf, or the store's truck. next time you road trip keep your coconut oil, (and your evoo, also) in the cooler. ALL fats WILL eventually become rancid. direct sun or high heat just helps it along rather quickly.
also, shop around. i used to pay $$$ at WF for my coconut oil also. now i pay $ and i get a great free mini cuppa joe and a red oval smile on the side, if you catch my drift...