Dextrine

[kv]

Hello to all!

I was wondering where to look for this stuff, in what sort of shops it could be found?
Or, a proper way to make it?

[Blaf]

Hello kv!

I found my Dextrine in Art shop...they charge little less than 10 Eu. for a kilogram. That's how I got mine. Never tried to bake my own so far. They say (they know everything) it could be made by baking corn starch, it should be spread in thin layer (say 1cm thick) on the bottom of your baking vessel while stove temp should be set between 200 and 250 C. From time to time, corn starch is to be mixed as to expose bottom layers to heat...when it becomes slightly brownish, the stuff is ready to use. I repeat gain - I haven't tried it myself yet and just read about it elsewhere. Which doesn't mean I won't do it sometimes...

Blaf

[kv]

Thanks Blaf! :)

[Duvel]

About the backing.. I've done it, it works great!
Just:
200 Degrees Celsius
4 hours should be enough.

Make sure you put a spoon trough every half hour.

[mr.stijntje]

nice to hear that you tried it, I didn't realy believe it at first
but,

4 hours should be enough.

4 hours is very much, I don't know if my mother will like it when I do it..

by the way, does anyone know the molecule formulas from corn starch and dextrin? to explain why it becomes dextrin after heating. I suppose it discomposes? (right word?)
and also to promise my mother there will be no smoke etc...
she doesn't really believe me

btw, here you can also find some information about it..

edit: excuse me, @ that site also the formula is called,

Formula: mixture of polysacharides

so dextrin has no single formula because its a mixture :)

[kv]

Well I also have doubts about heating it so long, 4 hours sounds to much, maybe 30minutes or so...

mr.stijntje have look here > http://en.wikipedia.org/wiki/Dextrine

[chemical cook]

i always make my dextrine by baking corn starch in the oven. i bake it for 3 hours at 200C. works great. but after 3 hours it smells like burned pizza's though. lol

[Exhile]

I can't tell the formulae now but the principal is to "crack" te polymers by heating, this way you obtain another endproduct, you can make dextrine ou of starch and sulfuric acid but the concentration can't be high and i haven't done it before.

[deadman]

Not trying to bring up an old topic, but I have made dextrin. Blaf I'm not real up to date on euros but that seams life an aweful lot to pay for dextrin. In America you can buy 1 pound (453g) for around 1 US dollar. So very inexpensive. When baking corn starch to reach dextrin you are trying to break it down from its long polymers into a more simple structure. The heat acts as a catalyst. When I make mine I leave it in at 425 degrees F. Which is around 218 centigrade. Everyone says 400-450 F is recommended so 200-225 C would work fine. It only takes me about 1-2 hours to achieve wanted results. It will slowly turn brown. Make sure to mix every 20 to thirty minutes. If you really want to find out if it is a bon-a-fide dextrin use iodine solution and figure out if it is still a starch. Just thought this would be useful and cheaper.