This topic has come up on another part of the forum.
Seriously folks, this is a very important issue. I think we should all look into it and see if its ok.
About 2 years ago, I read an article on this subject on the net, and it was frightening.
All I will say is that the doctor blamed this action for many of the woes of the western world.? This of course was only his opinion.? But if we are to be making curry a lot and for years to come, I think it would be worth clarifying.
Here's something I found:-
Alice,
I am trying to convince my good friend not to save the grease she cooks with for re-use. Instead of draining grease out of a pan after frying it, she saves and stores it to use again. It seems to me that grease that is cooked once is bad enough, twice must be horrible. Am I unjustly picking on her, or am I right that there is an even greater health risk when you cook with pre-cooked oil/grease?
Dear Reader,
Reusing cooking oil has been done for ages. There really isn't a problem, if done properly. The greatest hazard is allowing the fat to become rancid (spoiled) and deteriorated to the point it produces undesirable flavors and odors. Besides ruining what would have been a perfectly good meal, rancid oils also contain free radicals that are potentially carcinogenic.
To understand how to best re-use oil, it is important to know about smoke points ? the temperatures at which oil begins to decompose. If you heat oil to a temperature that is too high, it produces smoke fumes. Acreolin, a substance that makes your eyes burn, is given off as well.
The optimal temperature to fry foods at is 190?C (375?F). At higher temperatures, the food will burn on the outside, and at lower temperatures, the food absorbs too much oil and tastes greasy. Different oils have different smoke points. Oils with higher smoke points are better for frying. The following is a list of smoke points:
Type of Oil Smoke Point Temperature
safflower oil 265?C
sunflower oil 246?C
soybean oil 241?C
canola oil 238?C
corn oil 236?C
peanut oil 231?C
sesame oil 215?C
olive oil 190?C
lard 183 - 201?C*
(*varies depending on the diet fed to hogs and the part of animal fat that is derived)
Each time the oil is re-used, the smoke point becomes lowered. This is due to:
foreign matter in the oil (such as batter)
salt
the temperature to which the oil was heated
exposure to oxygen and light
length of time the oil remained heated
the number of times the oil was reused
Combining different types of oils also lowers the smoke point.
When oil becomes deteriorated, it appears dark and thick (viscous). It may have an off odor, and smoke appears before it reaches 190?C. If the oil smells funky and old, better to toss it away and replace it with fresh oil.Each time the oil is re-used, the smoke point becomes loweredThis would explain why I find it harder to brown garlic using the curry gravy oil.
The garlic tends to lie there looking defiantly raw.
I've been doing a lot of cooking experiments lately and? having read Curry King's latest demonstraion post, it set me thinking.
His demo was almost identical to one I had.
I was shown curry gravy and chicken vindaloo at home.
His curry gravy recipe was nearly the same as
three other curry gravy recipes I have been given or seen.
I really think we are as close as we will ever get to the flavour.
There is some reason why it is different when you cook at home.
I am (begrudgingly) happy and not searching for a missing ingredient anymore.
I will enjoy what we have instead.
Personally I still think it's a temperature thing.
The recipes we have are correct.
And more recipes , from any restaurant, will always be welcome
If you managed to cook them on a commercial high pressure gas cooker then they would be identical.
So if you still want to chase the flavour I think the only domestic possibilities lie with your microwave.
That gets really hot.
Have you noticed a microwaved reheated curry really takes on extra flavour?
I think that avenue of thought might have possibilities.
What about trying to make the curry gravy in the microwave from start to finish?
Apart from anything else, I don't want to believe, that I have been lied to.
The chefs that have helped me have all seemed really good people.
They have given up their free time to help someone, that they didn't have to.