Shortening vs. Oil
My oh my I’ve received a lot of questions about doughnuts the last couple of days! Reader Seth asks:
Joe, I notice you use liquid oil for your frying medium. I’ve heard that professional doughnuts makers use mostly solid shortening. Is that true? And if so, why?
An excellent question, and one I’ve been meaning to get to the last couple of days. The answer is yes, just about all commercially made doughnuts are fried in solid shortening. There are several reasons for this. First, as I mentioned earlier in the week, a solid fat is much more resistant to breakdown and rancidity than a liquid fat.
To explain why, I’ll need to get into a little bit of chemistry. The world of fat, as you’re probably aware, is divided into categories based on whether the fatty acid molecules they contain are saturated or unsaturated. What does that mean? Well, if you remember, I recently talked about how fat molecules are “E” shaped: a glycerol molecule with three fatty acid molecules attached. Those fatty acid molecules are nothing more than long strings of carbon atoms – atoms which can each be bonded to up to two hydrogen atoms (making a so-called “hydrocarbon chain”). If that sounds confusing, think of a line of pre-school teachers (carbon atoms) walking down the street, and each of them is holding either one or two toddlers (hydrogen atoms) by the hand. (Can you tell I have little kids at home?)
If every teacher has both hands occupied by a toddler, then that fatty acid is said to be saturated, full up with hydrogen atoms (as a side note I should say that should you ever see something like that in real life, hurry up and enroll your kid in that pre-school, because the teacher-to-student ratio is unbeatable). If one of the teachers in the line has a free hand, then the fatty acid is said to be mono-unsaturated. If more than one teacher has a free hand, or even two free hands, then that fatty acid chain is said to be poly-unsaturated.
The general rule of fats is that the ones that are high in unsaturated fatty acids tend to be liquid and the ones high in saturated fatty acids tend to be solid. But that’s not the only difference. Unsaturated fats, since they have molecular bonding sites available (remember those free hands) can bond to other types of “free radical” atoms (imagine unruly teenagers joining the parade). This process, known as oxidation usually occurs as the oil is heated and exposed to air. It causes the fatty acid chains to break into pieces, yielding all kinds of weird compounds including foul-smelling short-chain fatty acids, aldehydes and ketones. In the end, oxidation can cause the fat to go rancid.
So you can see why solid fats are valued so highly by people who fry a lot. They’re durable. They also have the advantage of being solid at room temperature, which means that once the food that’s been fried in them cools down, the residual oil won’t “weep” oil onto plates, napkins or cardboard boxes. Firm fat also tends to feel less greasy on the tongue.
But doesn’t most shortening have trans fats in it, Joe? That was the rule up until very recently. Just about two years ago now, inexpensive trans-free solid shortening became available to the food industry. Nowadays more than a few doughnut shops fry in trans-free fat, though by no means everybody. As someone who’s never believed the hype surrounding trans fats, that’s not important to me. If it is to you, you’ll be comforted to know that you can once again enjoy doughnuts without the specter of trans fats hovering over you.
What about the inside of the doughnuts? Is there any different when frying with oil vs. frying with shortening? And if am using Crisco for frying, how much should I use?
Also I’d like to know how many times shortening can be used for frying.
Hi Joe!
No, the type of fat doesn’t much influence the interior of the doughnut, unless it soaks in. In that case, doughnuts fried in liquid oil will to be wet and oily, and doughnuts fried in shortening will tend to be firm and fatty.
I’m reminded here of of so-called “old fashioned” doughnuts which are fried at a very low temperature so as to encourage the melted shortening to seep in. Once cool, these doughnuts are very dense and delicious, until you consider that they’re about 30% fat.
Shortening can be used at least ten time for frying at home. In commercial doughnut operations, the shortening is never changed. More solid shortening is simply added to the fryer as the doughnuts absorb it. It’s a simple system, if a little nasty-sounding.
As for how much, you’ll want to use at least several pounds (pints). So the doughnuts float. That’s the only general rule!
Good luck!
– Joe
Hi Joe,
I just found your site here and have been looking for “healthier” oils yet solid. I have been using Canola oil at home for my apple fritters I plan to start selling via food truck vending. I noticed that the oil I used (from Costco) smelled a bit off when I opened the bottle. That is not the real problem though since I can change brands. However, it does get rancid in the pan quite early on. I read your article about the two types which was very helpful. Which confirms my idea that I may want to use a solid oil. So I am looking for as “healthy” (as far as grease goes) an alternative as I can without going into lard (lots of Kosher people here).
BTW, though you answered well about the two types, you never answered as to why you use liquid over solid in your reply.
Hi Boyd!
I use liquid over solid at home because it’s just easier. If I were frying professionally I would use a solid fat for sure since it’s so much more durable. As far as “healthy” fry mediums go, I guess it all depends on your definition! 😉
A lot of people define a healthy solid fry mediums one that is transfat free. These days it’s very easy to find trans-free fry mediums from places like Sysco and Bakemark, or any other major ingredient wholesaler. In fact it’s probably harder to find fry oil WITH transfats! I would call a rep or visit are warehouse in your area and see what they have on offer. You’ll probably be pleasantly surprised!
Let me know if this answers your question. Cheers,
– Joe
i didnt have shortening to make corn bread and it came out hard. not fluffy.
because i used olive oil?
Hey Frank!
It’s hard to know without the recipe. However if the instructions called for creaming the fat then yes that’s probably what happened. Solid fats hold air bubbles when they’re whipped up and that helps create a lighter texture.
Better luck with the next batch!
Cheers,
– Joe
My cousin made and sold donuts and they were great. They were very dark brown on the outside but tasted sweet inside-yum. I can not figure out what oil she would have used. They almost looked like they were fried for along time. She could not keep up with all the orders,they were that great. I have her receipe but not the oil. Have any ideal what it could have been?