Casting Food

[JennaReneeCleary]

Hello!  

I have a casting question.  I would like to cast food.  Specifically the pieces to a gingerbread house I bought.  I would ultimately like to make the gingerbread house out of clay but am looking to make a mold first.  The pieces are flat for the most part.  I would  to make one pieces press molds for each piece.  Is it possible to make a mold of the gingerbread houses out of plaster?  Would I need to coat the gingerbread cookie with anything? I thought about making the molds out of silicone, creating them out of clay, and then using the the clay pieces to make a plaster mold but that seems overly complicated.  It's been awhile and I am feeling a bit rusty.  I tried to research but am not getting a clear answer.  Any advice would be appreciated.  : ) 

[Mark C.]

You need to understand molds well for this-like NO undercuts for starters .

yes you need to make it smooth an firm and slippery. 

I recall many years ago a gingerbread thred many do a search on that on main page as the slip cast page is new

Edited December 7, 2022 by Mark C.

[Min]

23 hours ago, JennaReneeCleary said:

Would I need to coat the gingerbread cookie with anything? I thought about making the molds out of silicone, creating them out of clay, and then using the the clay pieces to make a plaster mold but that seems overly complicated.

If plaster sticks to the cookie then yes you would need to seal & soap it. I've bought gingerbread house kits that have plastic trays / boxes that the pieces come in, if yours does then another option would be to fill those with soft clay then cast it upside down on the plastic. Is making the gingerbread slabs with clay and then casting those while the clay is still damp an option for you? Wouldn't need to soap the slabs.

Welcome to the forum!

 

Edited December 8, 2022 by Min

[Callie Beller Diesel]

The first slipcasting project we were given in college involved making moulds from food items that were then to be made into decorative pots. Some things we found:

Some softer items like peppers, zucchini and one extremely memorable fish head wound up partially cooked. Be mindful of the exothermic reaction of plaster, and how that might affect something like icing or candy decorations on the cookie panels. 

Some things were pretty brittle, and the weight of the liquid plaster broke the food item when someone attempted to make a case mould. Those items would have benefitted from having the texture taken by another method, like using plaster bandage as a base layer, removing the item and reinforcing the bandages with plaster. If you have to use the cookie itself, I’d be inclined to do a press mould rather than something you’d pour slip into.

Stuff can and will get stuck in undercuts in the plaster, even if you use mould soap. Consider filling in some textures at least partially, or sealing the food item with a few coats of varnish. If you try to clean out bits from the creases in your mould before it’s fully cured, it’s pretty easy to damage the mould. If you wait until the mould has cured, there’s a strong possibility of something gross happening. 

 

[Jeff Longtin]

To pick up on Min's point: you are aware that they make "kits" that are essentially rubber molds that enable you to press cookie dough into them and bake your own gingerbread house?

A simple option would be to make a plaster mold of the plastic/rubber kit (positive) and then make another plaster mold (negative) to repoduce the plastic tray in plaster form. Then use this plaster form as a press mold for clay.

Have you ever heard of alginate? Essentially its a gelatin like product that is skin safe. The nice thing about it is that it doen't get hot. You would still need to seal your current house form but the alginate would allow you to mold the form as is. (without too much concern for undercuts) Once molded you would need to make a plaster form and then a plaster mold BUT you can, at least, get a nice mold of the form as is.

To pick up on Mark's point however: even if you can find a way to mold the thing with undercuts you still need to keep in mind that when you pull the clay out of the mold the undercuts will tear the clay.  Therefore its best to reduce/eliminate undercuts, as much as possible, so the clay pulls away easily.