fallen rotting apples

Hello Folks

I've just dug out my runner bean trench for next years crop and dumped loads of rotting, fallen apples into it (leaving some for the birds over the winter period), along with manure from the compost heap, before filling it in again to rot down.  I'm hoping that the high liquid content of the decomposing apples will benefit the beans when planted next year.  Though I am now left wondering if the acid content of the apples will be detrimental to the growth of the runner beans.  Any thoughts or comments on the matter?  Thanks