Hi Rita, 

I know it is tempting to make use of all of the "windfall" apples that come off a productive apple tree near the end of the growing season, but the Extension Service does not recommend using these apples, especially for fresh juices or for canned products. There are a few reasons behind our recommendation.

First, windfall apples, especially later in the season, can be overripe. Overripe fruit in general tends to have a higher pH (less acidic) than freshly picked fruit from the tree. Acidity is a key factor in preventing some microorganisms from growing. If you cook and can with fruit that is overripe, you run the risk of creating a less acidic product that might allow pathogens to grow and make people sick.

The second big reason we advise against using fallen fruit is because of the added bacteria those fruit have encountered when they hit the ground. Animal feces and  microorganisms in the soil can cling to the fruit's peel, and additional bruising and insect damage give pathways for mold spores to enter. Juices made from windfall fruits have been known to make people ill (fatally in some cases), and canned products like applesauce and apple butter are more likely to spoil when made from windfalls because of this added "bacterial load" that isn't fully eliminated during the canning process.

So the short story is: play it safe and compost those fallen apples.

Thanks for using Ask Extension!

Jared