Gastronomic Glue

[Anneke]

Here's a sticky question for ya'll; honestly, you'd think they would have taught us this in cooking school...

Im trying to figure out in which circumstances you would use egg wash, egg white, flour slurry etc as a sealer for dumplings, raviolis, spring rolls etc. What is this choice a function of? the cooking medium (ie: oil vs water)?

For example, we just made some raviolis with wonton skins ( ..I know) at the hotel. We sealed them with egg whites. I just found a recipe (same) that uses a flour wash. I just wonder which one would hold better in boiling water...

[shroomgirl]

I use cornstarch slurry... for boiled filled dumplings

[Anneke]

Ok.

Why?

[phatch]

My opinion is that it has to do with available starch/protien to coagulate and bind coupled with the cooking method.

For fried, it seems water and it's slurries as well as eggs will work.

For boiled, you run some risk on diluting the glue before it sets. Lots of boiling water helps so the temp doesn't drop too much when the glued item is added.

Most boiled items have a starch based wrapping so there is usually plenty of binder to work with. A key is how moist the item was before boiling. Wonton skins just wetted and dunked haven't been reliable for me as the skin is dry enough that it just sucks up the binding water instead of setting. Some extra water or a stickier binder has been better for me here.

Pie type doughs and dumplings are fairly moist, so just a bit more water and pressure have worked there for baking and frying.

As to the egg wash vs. the egg whites, I think the main difference isn't in binding but in final presentation. Could also be the fat in the yolk messes with the binding in some cases? I don't know really.

Egg would seem to spatter less and set faster when fried than water based glues would.

Just my guesses.

Phil