I would think that your home-made granola would be ok...and it sure sounds delicious
If you get organic dried fruit to add to your granola (try dried cranberries - yummy!) or dry your own at home, then it should be safe also... Peeling fruits known to be higher in sulfites also can help, since much of the sulfite is contained in the skins.
- gives a table of common food items that may contain or do contain sulfites. Keep in mind that organic versions of these things may contain less or no added sulfites.
All corn derived ingredients - corn starch, corn syrup, etc. - will contain sulfites because sulfites are added during processing of the corn.
Organic food is not allowed to have sulfites added, but you would still need to watch for innate sulfite content; i.e., organic raisins will still be higher in sulfite than many other organic dried fruits because the grapes themselves contain sulfites.
Something that may help is to make sure you are getting enough Magnesium, Molybdenum, Zinc, Iron & Vitamin B12 (may not be getting enough B12 from food and/or a multi-vitamin, so you might need to get a separate B12 supplement; a dose of B12 + Molybdenum can help stop a sulfite reaction for me...don't know if that works for everyone with sulfite reactions though). These are important nutrients that the body needs to correctly process sulfites, and many people are deficient in at least one of these nutrients (e.g., I've seen estimates of 50+% of USA is magnesium-deficient due to inadequate magnesium-rich food consumption).
Correcting deficiencies in the nutrition required for sulfite processing can reduce sensitivity over time...depending on epigenomic factors (Dr. Amy Yasko has a lab test panel that can detect altered genes involved in controlling methylation and associated metabolic cycles in the human body that are involved with sulfite processing, but her test is expensive; a nutritional supplement trial may be less costly and more informative - discuss with your doctor).
I hope this is helpful. Take care,
Too many health issues to list...