No-bake cheesecakes only need refrigerated, so you don't have to worry about the usual cake considerations, such as time, temperature, lift and browning. However, you have one concern that can make or break a no-bake cheesecake: Gelatin. Improper measuring, poor mixing and using high-moisture cheeses, among other factors, can prevent gelatin from setting properly or altogether.
Blooming the Gelatin
Improper blooming causes the majority of gelatin mishaps. Mix the gelatin into a small amount of warm liquid and allow it to fully hydrate and soften, or bloom, before adding it to the cheesecake base. Gelatin needs about 4 or 5 minutes to fully bloom. Furthermore, you must use warm liquid for blooming; cold liquid causes the gelatin to form in strands instead of dispersing evenly.
If bloomed gelatin sits too long, it solidifies and won't mix with the cheesecake base. Add the gelatin to the base as soon as it blooms. If bloomed gelatin sits more than a few minutes and starts to solidify, you might be able to correct it. Bring a small amount of water to a boil in a saucepan and place the bowl of gelatin in it. Next, stir the gelatin vigorously with a fork as it heats. If heating and stirring the gelatin doesn't work, start over with fresh gelatin. Don't add more water to the gelatin. Adding more water skews the gelatin-water ratio and the cheesecake won't set.
Gelatin needs refrigerated at least 8 hours to set properly. When used to thicken and stabilize a cheesecake, you're looking at 12 to 24 hours of refrigeration depending on the cheesecake's thickness. Check a 9-inch cheesecake for firmness after 12 hours and, if needed, every hour thereafter.
One tablespoon of gelatin will hold and thicken about 2 cups of liquid. However, when working with cheesecakes, it is a bit more complicated -- soft cheeses vary in their water content, and can skew the gelatin-water ratio. Scoop 1 tablespoon of the cheesecake mixture and tilt the spoon downward -- it should take 1 full second for the mixture to drop from the spoon if the gelatin-water ratio is correct. If the mixture is too runny, mixing in a tablespoon of powdered sugar will help stiffen it, but only slightly.