I made a delicious raspberry filling for a buttercream cake but am unsure if it needs to go in the fridge tonight (I did look around but felt like I couldn't find a consistent answer?) Here is the recipe I used:
- 1 1/2 c frozen raspberries
- 2T cornstarch
- 2T lemon juice
- 1/4 c sugar
Thanks for any input! I've done tons of cakes but am new at the fruit filling!
I prefer to err on side of caution where food safety is concerned. Unless you've had your product lab tested, there is no way to know if your additives suppressed the water activity and ph levels below the threshold.
Water activity level determines safety and storage of food. Water activity is the measurement of unbound water molecules tin the food. When water molecules are not bound to food, it becomes available for microorganism to reproduce.
The government established a water activity level of .85 and below and an ph level of 4.5 below as the threshold for inhibiting the growth of harmful bacteria.
Sugar, salt, protein, and starches can reduce water activity by binding water molecules, making water unavailable to bacteria. Acids, like lemon juice or vinegar can be added to lower levels.
While freezing inhibits bacteria growth, it does not kill bacteria. Once thawed, if the ph level and water activity are above the threshold, bacteria will quickly grow. There's no way to know how much bacteria is on your thawed fruit.
Your filling has both an acid and a starch. That good. But it's impossible to know if it's sufficient without testing.
Yes, it is an awesome response and I agree w/her:)