How to esters work?

[Baynne]

Ok, first, I'd like to thank everyone here.  I've learned SO much since I've joined the Hive that it's sickening.  But since my quest is one for knowledge, not dope, let's go here:
      How do esters work?  I've read about how to make them, but what conditions are condusive to forming an ester?  How about breaking it?  What would inhibit the ester formation?  Any tips on these things?  Can methamphetamine form an ester with acetic acid or sulfuric acid? 
I have UTFSE and seem to remember reading something about an acid attaching between two molecules of ephedrine.  Some have said that an excess of acetic acid helps form the ester.  I have been led to believe that refluxing an ester in h2o will break it.  I also seem to think that esterification protects one part of the molecule so that another can be reduced.
Any information would be appreciated.  Or leads on what to look for?  Sorry if I've missed this info before.  If I did, just flame me and point me in the right direction, please.

[ApprenticeCook]

chemistry text books, that would be a start....

esters are made from carboxylic acids and alcohols heated with conc acid (norm sulphuric).
Esters are broken when heated with dilute acid.

Can methamphetamine form an ester with acetic acid or sulfuric acid?

No. esters do not form between amines and anything, they are between carboxyls (R-COOH) and alcohols (R-OH).

Look at a chem text book.

-AC

[Baynne]

[ADDkid]

Esters are more useful then they appear, example, when doing claisen condensation, and mixed condensation.  For example ethanal and ethanoxide in a solution of benzyl acetate would give a benzyl propane compoud, which could be turn into methamphetamine and amphetamine. Esters are just has useful as aldehydes or alcohols, it just takes creative thinking to use them.
P.S. My example should not be taken lit. It was just a possible reaction.