So last night i made the raspberry filling found here: http://cakecentral.com/recipes/2503/raspberry-filling
I made everything according to directions, and stuck it in the fridge to thicken overnight.
We as soon as I added the cornstarch and put it back on the heat, the mixture started to thicken. After the 5 mins of simmering it was thicker and I put it in the fridge to thicken more. This morning I pulled it out and it hasn't thickened any more It is a thick spoon coating syrup kinda, but still definitely more liquid than gel. As this consistency I think it will not work as filling.
My question is: Is there anything I can do to help it thicken more? More corn starch and more boiling maybe? I don't want to mess it up because the taste is great, but right now I think i would have to mix it with BC to use it.
If it were me, I would put it back on the heat and add more cornstarch. Probably not much. You may need to add some sugar too.
Add a little bit of unflavored gelatin and put it back in the fridge for a while. That has worked well for me in the past.
I make a glaze starting with a cup of fruit and 3/4 cup water, 1 cup sugar and 3 tablespoons cornstarch. Just revising my recipe for the water and cornstarch you should have been using at least 8 tablespoons of cornstarch. This doesn't include the added juice from the fruit. Remember my recipe is for a thick glaze for a fresh fruit pie not a cake filling. You have already added 6 tablespoons of cornstarch I would make a slurry of 6 more tablespoons of cornstarch and 1/3 to 1/2 cup water. Bring your syrup to a boil and whisk in 1/2 to 3/4 of the new cornstarch slurry. bring to a boil and cook until translucent. (You may need to add more of the slurry or a bit of water if it is too thick.) This will thicken as it cools but it certainly doesn't need to sit in the frig. overnight. If you want a stronger color, add a drop or two of liquid food coloring.