!!

Guests can now post!

Welcome to Intelligent Answers.  As a guest, you are now able to post a question, subject to getting through our spam-bot filters.  However, if you want to answer any questions, you will need to register.  Thanks for visting!  (BTW - guests cannot post links, and if you post spam, we will block your IP and report you to every spam protection site we can find - we work hard to keep this site spam free for the benefit and enjoyment of our members!)

Author Topic: What, exactly, is the difference between oil, fat, and grease?  (Read 2887 times)

Wumpus

  • Guest

Just bought some strong detergent to use on my car engine, and it says on the can that it can also be used as a washing up liquid.

So in what way is car oil/grease substantially different/similar from cooling oil/grease, if they respond to the same detergents?

And on a biological front, how is a fat different from a grease?

Offline Hiheels

  • Founder member, in the naughty corner for smoking in the café.
  • Administrator
  • Dean
  • *****
  • Thank You
  • -Given: 78
  • -Receive: 45
  • Posts: 3946
  • Helpfulness: 109
  • Yes, yes, very nice. Now put it away.
  • Referrals: 0
Re: What, exactly, is the difference between oil, fat, and grease?
« Reply #1 on: 01 July, 2009, 08:07:53 PM »
From http://www.ci.austin.tx.us/water/faqgrease.htm#a3 comes:

3. What is the difference between oil and grease?

The terms are often used interchangeably, but they are very different substances. Grease is the solid white residue left over in the cooled pan after frying meat such as bacon. Oil, such as vegetable oil, is the liquid left over from frying foods and never turns into a solid.

So basically oil never sets, but grease does...I'd wager they're all classified as fats - but I'll see if I can find anything to back up or refute that supposition...

Right, I'm back and I've found http://chemistry.about.com/od/chemistryglossary/g/fat.htm
Now, on this site there's a chemical definition of fat, but there's not the same for either grease or oil, so could it be that fat is the only one with a chemical definition?
« Last Edit: 01 July, 2009, 08:20:27 PM by Hiheels »

Wumpus

  • Guest
Re: What, exactly, is the difference between oil, fat, and grease?
« Reply #2 on: 01 July, 2009, 08:59:05 PM »
Interesting sideline.... does your answer mean that there's no such thing as vegetable grease?


Your link contains the line...

"Fats may be either solid or liquid, though sometimes the term is reserved for solid compounds."

So maybe fat (in the cooking sense at least) could be a generic term covering both oil and grease?


Offline Hiheels

  • Founder member, in the naughty corner for smoking in the café.
  • Administrator
  • Dean
  • *****
  • Thank You
  • -Given: 78
  • -Receive: 45
  • Posts: 3946
  • Helpfulness: 109
  • Yes, yes, very nice. Now put it away.
  • Referrals: 0
Re: What, exactly, is the difference between oil, fat, and grease?
« Reply #3 on: 01 July, 2009, 09:22:15 PM »
Just casting my mind over vegetable secretions and I would have to agree that there's no such thing as vegetable grease, that I can think of anyway.

I think you may be right that fat covers a multitude in some contexts, but there are so many references on t'intertubes to all three I kind of think there must be some sort of difference, but apart from the chemical thing I can't find anything to say what that might be.
I may have to cry  :'(