This is an example of creating your own recipe can be a dangerous practice. While bacon and green beans are both low-acid foods, there are no processing recommendations for canning bacon. Therefore, can the beans by themselves. Then when ready to eat the beans, add the bacon just before serving.
Adding any fat or butter to home-canned products, unless specifically stated in the recipe may slow the rate of heat transfer during processing. This will result in an unsafe product. Additionally, the fat could seep in between the lid and jar rim and the lid will not seal properly.
Spices or herbs may be added in small amounts before processing.
Source: https://learningstore.uwex.edu/Assets/pdfs/B1159.pdf
