When you heat cold pressed oils or wood pressed oils especially Sesame (Gingelly oil), Groundnut oil, Mustard oil in Summer or rainy season, they generate foam. Many customers ask us why heating cold pressed oil generates foam?
Foaming in oil is a natural phenomena. Especially during summer or rainy season when humidity is high or there is moisture on the surface of vessel, it is very natural for cold pressed oils to foam.
Then why refined oils don't foam?
If you read label of refined oils carefully, you will notice a chemical added to refined oil called "Anti Foaming Agent".
Usually, Polydimethylsiloxane is used as a anti foaming agent which stops formation of foam in refined oils.
Wood Pressed or cold pressed oil on the other hand are oils in their natural form and hence they tend to behave in their natural manner i.e. generating foam when heated.
What to do, if my cold pressed oil is foaming?
Solution is very simple. Just make a small ball of tamarind may be 1 inch diameter.
Fry this tamarind ball in oil first. The ball will soak all the foam in a minute or two.
Once all the foam is soaked and the oil is hot, start frying the food as usual.
Remember, Oil foaming is not something you should worry about when it comes to cold pressed oil.
Only if the oil is smelling bad while foaming or its tasting bitter, there might be some issue.
For clearer explanation about what to do if cold pressed oil generating lot of foam, please check this video on youtube.
Reference Links
Read about Synthetic anti-foaming agents and how they work here.