Let’s talk about frying, readers. My lab group recently bought a deep-fryer, named, for reasons that I will not care to speculate on, the FryDaddy (available at fine retailers like Target and Amazon). And we bought this because fried food is delicious, and this is a great way to make fried food in a relatively convenient and non-messy manner. Once we had the FryDaddy, we then thought….hey, we’re scientists, how about trying to actually do some science with this? In particular, let’s look at what happens when you re-use frying oil several times, like many restaurant chains do.
So we sat down one Wednesday morning with lots of food to be fried…..
And we kept frying…..
And we kept eating…
And in between each frying, we took samples of the oil out to test for further analysis.
When there was nothing left to fry and no room left in our stomachs, we looked at the oil samples, which looked something like this:
So the oil looks darker the more it is used for frying, which means that there are likely more contaminating chemicals and at higher concentrations the more it used. We’re still waiting on more technical data to confirm, but in the meantime, a brief google search indicates that even though other people have found similar things, many cooking experts and even some scientists say that reusing frying oil is perfect safe. Check out links HERE, HERE, and HERE.
There are some “rules” apparently, about which oils tend to break down more easily at the higher temperatures of frying, and also thoughts about avoiding particle contamination from the food that you have already friend in there.
I think this last point may have been where we went wrong. How do I know? Well the fried pickles at the end did taste remarkably like the fried mozzarella sticks, which were the first things we tried. Oh, well.
Happy frying, readers!