pH Conversion with microprocessor??

[KuntzBrewing]

Are you aware of any sensors that can detect starch percentage in solution. I'm thinking of making an automated brewing system. Like I hit "start" and walk away for 6 hrs. In order to do that I want to make sure starch conversion is complete

 

[KuntzBrewing]

Sorry I was spaced out something awful when I wrote the title. I meant starch conversion. (That's what I get for Google searching phone probes while making a new thread)

 

[annoyingrob]

Way back when, I used to work for a company that manufactured electronics for quick prototyping.

25 bucks gets you a Ph sensor
http://www.phidgets.com/products.php?product_id=3550

30 bucks gets you an adapter board that can read the signal, and convert it to a 0-5v analog voltage.
http://www.phidgets.com/products.php?category=6&product_id=1130_0

I'm not sure whether or not 55 bucks is worth it to you, but it's a pretty good all-in-one solution. They're meant to be used with their USB interface boards:
http://www.phidgets.com/products.php?category=0&product_id=1018_2

but they will interface with anything with an analog converter.