This was my first year canning applesauce. My first batch was a little too thin for our liking, but I tweaked what I did a little, and the next two batches came out great. I have some apples left, but not enough to make it worth canning. I was wondering if I could open my first batch, add it to the apples I have remaining, and process like I normally would.
Yes, that should work just fine.
When you are opening the first batch, it’s “the same” as a freshly made batch, at least from a food safety perspective.
As applesauce is not sensitive to longer cooking time (unless you are making apple butter, but that’s totally different and would need way longer times and evaporation), you are also fine taste wise.