I just got licensed for home baking (yay!), but with a home processing license here, I cannot make any products that require refrigeration for safety reasons as a finished product.  There is a difference between refrigerating for quality (melting, etc. in hot weather) vs. needing refrigeration in order not to go bad and spoil.  I'm sending in a few frostings just to be on the safe side for water activity level testing, but I'm trying to keep costs down.  Are any of the following KNOWN to be shelf-stable with low water activity levels (and please don't say just from experience, it has to be known to be tested low).  Thanks!

1)  Wilton buttercream frosting made with 1/2 shortening, and 1/2 butter

2)  Wilton buttercream frosting made with 100% butter

3)  Cream cheese buttercream frosting (made with 8 oz. cream cheese, butter and sugar) - this is one that I know comes up a lot.  Apparently 8oz. of cream cheese can be stabilized with 4 cups of sugar, but I want to be sure).

4)  Vegan buttercream - same as Wilton's recipe, but using Earth Balance butter and soymilk instead of regular butter

5)  Clothespin cookie filling - made with 1 cup milk cooked with flour, then mixed with butter, marshmallow cream, a little shortening and superfine sugar. This one melts at room temp but I'm not sure it's "unsafe" so it needs to be tested.

Thanks so much!

Alle

AHere are several recipes that have been tested for acidity and water activity: http://www.texascottagefoodlaw.com/Resources/Recipes.aspx

Wow, I didn't know lemon curd of any kind was NPH.  I'm very happy about this!