image courtesy darwinbell

The Ins and Outs of Onion Sizes

Posted by 78a7e62a tiny Jonathan Soma on may 7, 2012 under Blog Post

We've talked about how to cook onions before, now let's talk about onion-industry-approved facts about how they're sized. 

Maybe you've been curious about what a medium onion is. I was, too, until I found the United States Standards for Grades of Onions from the USDA's Agricultural Marketing Service. Now, I know we aren't ones to let the government boss our food around, but their definition of a "medium onion" is one with a diameter of 2 to 3.25 inches. That's a pretty big difference, I'll bet the bigger onion has a lot more inside it.

Mathletes, let's go! Volume of a sphere with a 2" diameter vs. volume of a sphere with a 3.25" diameter?

2" diameter onion = 0.3 cups

3.25" diameter onion = 1.24 cups

So, lesson learned. Per USDA parlance, one medium onion can have over four times as much onion in it as another medium onion. But no one listens to the government! Let's see what Industry has to say.


Courtesy the Idaho-East Oregon Onion Sizing Guide

That's a prepack yellow onion - the kind that come in bags - sitting inside the looming spectre of a "super collosal" onion. There's about four pages of talk about how you definitely should really absolutely make Bloomin' Onions out of super collosals, and I think I agree.

Those of us looking for info on how much onion is in an onion are in luck: on page 18 of the Onion Sizing Guide we get a yield guide.


Okay, so plenty of fun facts for us here. A 3" onion has about twice as much onion as a 2 1/2" onion, and a 3 1/2" has about 75% more than a 3" onion. We'll get to why that matters in a second, I want to talk about deep frying these things.

If you're looking to make onion rings, you damn well better pick a big onion. A wimpy 2 1/2" onion can only have about 55% of its weight turn into those delectable loops, while a 4" onion can dedicate 70% to the deep-fried cause. It'll make 45 fucking onions rings! I am swearing out loud now, and with gusto.

But back to the main point: when you're using onions to cook something, a slightly bigger onion gives you much more onion to work with. Those bags full of prepacked onions are really easy to truck home, but is it worth the fact that you'll have to cut up twice as many onions?

I don't think so, because I hate peeling onions. And bless my heart, there's a chart for that one, too.


And there we go! Peeling onions is a huge time-suck, as proven by science, and small ones make you the worse for it. It takes about 30 seconds to peel a pound of 3 1/2" onions, versus about 100 seconds to peel a pound of 2 1/2" onions. Don't buy bagged onions, buy bigger onions. Your life will be better! End of story.

But not really the end of the story, actually, because here's a fun video advertisement I found for an onion sorting machine. Featuring words like singulation loading carriers!

Tagged with food onions facts

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