I've had a few request for the gumpaste recipe that I use to make the petals in the exploded rose video, but I can't give it out. For one, I sell it in my Etsy shop, but I also genuinely don't know it for small quantities.
I make my gumpaste in very large amounts because I tend to go through it really fast. It's kind of a hybrid of a few different recipes, and to reduce the ingredient quantities to something that would be easily made in small amounts is more of a mental exercise than I'm willing to do. So go buy some of mine, but in the meantime you could try some of these other recipes that are commonly used.
The one that people seem to be using a lot now is the Nicholas Lodge one from the Craftsy classes. I personally find this one too brittle and too much like a pastillage as far as the chalky dried texture goes. I'm not a huge fan of it overall, but people seem to be using it because it's fast to make.
That recipe is: 125gram egg whites
825 gram confectioner's sugar
30g tylose powder
Beat the eggs in a stand mixer for a minute, then add most of the sugar. Beat it on high to make a meringue, then when it gets to soft peak stage add the tylose and beat it on high for a few seconds. Wrap it well and refrigerate it for 24 hours before using if possible.
Another recipe is the "quick gumpaste" recipe, which isn't really gumpaste, but it works. For that all you have to do is add 1 1/2 tsp of tylose to 1 pound of store-bought fondant, or 2 tsp of tylose to 1 pound of homemade fondant. The only problem with this version is that it tends to be more susceptible to humidity, so if you refrigerate it for any length of time it can soften up. (Note: this recipe will NOT work with fondarific, which has candy clay in it and won't harden up as a result!)
The last one is the "classic" gumpaste that is also courtesy of Nicholas Lodge, but this one came from an earlier textbook. You can mess with it to change the consistency if you live somewhere really humid or dry.
3 1/2 cups confectioner's sugar
1/4 cup cornstarch
3 tsp gum tragacanth
5 tsp cold water
2 tsp powdered gelatin
3 tsp shortening
2 tsp corn syrup
1 egg white
Put the dry ingredients in a stand mixer bowl and stir them together. Bloom the gelatin it the water, then melt it over a hot water bath, adding the corn syrup and shortening. Stir until it's all dissolved then add it to the dry ingredients. Add the egg white and beat it on slow until it's all mixed. Turn the mixer to high and beat until the gumpaste is white and stringy, 5-10 minutes or until it sounds like your mixer is going to struggle and die. Wrap airtight and refrigerate for 24 hours if possible. Knead with shortening to get it ready to use.
Try these recipes out, mix them up, change them around, etc. You'll find one that you like to work with and that dries the way that you want it to. There are many variations on the basic recipe, so it's worth playing around with them a little.
Kara Buntin owns A Cake To Remember LLC, online cake supplies at www.acaketoremember.com and www.acaketoremember.etsy.com