At work we have problems with our Cream Cheese filling--Think of a filling that gets baked for a danish product. We have a problem with our Cream Cheese filling going bad after about a week. The formula contains Sour Cream, one of the theories was is that the sour cream is beginning to culture the cream cheese which is producing the lactobasilic acid which is providing the off flavor... The other theory was that our cake flour was not completely incorporated into our Filling and that the cake flour was beginning to ferment and cause souring in our recipe. Here's the formula. Cream Cheese 100% Sugar 25% Cake Flour 6% Salt 1% Vanilla 1% Lemon Zest 0.5% Eggs 12.5% Sour Cream 17% We have some thickening problems with this recipe as it is, Would it be possible to sub in a modified food starch for the cake flour and if so, what quantity--How does the thickening power change?--What if it's the sour cream, Should I just omit that and sub in something different, or just get rid of it all together and add in more cream cheese.