Why does my rusk go soggy quicker in coffee?

  • 4 Replies
  • 2577 Views

0 Members and 1 Guest are viewing this topic.

*

Offline royden

  • First timers
  • *
  • 1
    • View Profile
Why does my rusk go soggy quicker in coffee?
« on: 19/07/2010 18:30:02 »
Roy Hodgskin asked the Naked Scientists:
   
Hi Chris,

How come when I dunk a rusk in coffee (hot water + instant), it goes soft; but went I dunk it in tea (hot water + a teabag) or hot chocolate (hot water + instant hot choc) it takes a lot longer to get soft, if at all?

Regards,

Roy Hodgskin

What do you think?
« Last Edit: 19/07/2010 18:30:02 by _system »

*

Offline RD

  • Neilep Level Member
  • ******
  • 8185
    • View Profile
Why does my rusk go soggy quicker in coffee?
« Reply #1 on: 20/07/2010 20:36:41 »
Possibly an unfair comparison because of inconsistent rusks, e.g. comparing rusk from freshly opened pack with one after the pack has been opened for a couple of days and consequently has gone a bit soft. 

For a fair comparison all variables, except type of drink, should be kept constant:
rusks from the same pack, dunked at the same time, in drinks of the same volume and temperature.

It would also be necessary to repeat the experiment many times to see if there actually is a sogginess bias.
« Last Edit: 20/07/2010 20:44:33 by RD »

*

Offline imatfaal

  • Neilep Level Member
  • ******
  • 2787
  • rouge moderator
    • View Profile
Why does my rusk go soggy quicker in coffee?
« Reply #2 on: 21/07/2010 11:18:16 »
Heat differences? - you let your tea brew, you have to stir the chocolate like crazy to avoid lumps, but the coffee is ready as soon as hot water is poured.  the coffee is on average hotter than the other two - just a guess.
There’s no sense in being precise when you don’t even know what you’re talking about.  John Von Neumann

At the surface, we may appear as intellects, helpful people, friendly staff or protectors of the interwebs. Deep down inside, we're all trolls. CaptainPanic @ sf.n

*

Offline Geezer

  • Neilep Level Member
  • ******
  • 8328
  • "Vive la résistance!"
    • View Profile
Why does my rusk go soggy quicker in coffee?
« Reply #3 on: 21/07/2010 17:15:23 »
Some coffee beans are quite "oily", so perhaps coffee tends to "waterproof" the rusk? However, I don't think instant coffee has the same properties.

EDIT: Wait a minute! I read the question upside down  [;D]. Forget the oily idea!
« Last Edit: 21/07/2010 20:56:14 by Geezer »
There ain'ta no sanity clause, and there ain'ta no centrifugal force ćther.

*

Offline RD

  • Neilep Level Member
  • ******
  • 8185
    • View Profile
Why does my rusk go soggy quicker in coffee?
« Reply #4 on: 21/07/2010 23:09:49 »
If there is a sogginess bias it could be due to one drink being a better solvent, or surfactant,
 or possibly some enzymatic action.   
« Last Edit: 21/07/2010 23:18:32 by RD »