Red Fife is a wheat, so it does contain gluten and isn’t something that individuals with celiac disease can eat. That being said (well, written), Red Fife is one of the varieties that some people with gluten sensitivity say they can eat. From what I understand, we haven’t yet been able to definitively conclude why this is the case: one theory is that the long-fermentation process used with sourdough breads made from heirloom grains makes the gluten easier to digest. Another theory states that modern wheats have somehow been bred to be less digestible than heirloom and ancient wheats.
Hoping to find something more conclusive about Red Fife, I did a deeper dive on its protein content, based on the results of farmers and millers who’ve sent their grain off for testing. I’m seeing a range between 12% and 15.4%, which makes this a high-protein wheat. There seems to be some confusion on the internet about protein and gluten content, and while trying to find sources that use those terms accurately, I ran across this clarification from Loiselle Organic Farm, whose Red Fife from that season tested out at 12.2% protein: “Contrary to popular belief, Red Fife heritage wheat does not have a lower total gluten content than other newer varieties of bread wheat; this was confirmed by lab testing we commissioned at SunWest Food Laboratories in Saskatoon in 2006. However, and besides Red Fife’s exceptional taste and baking qualities, we have preliminarily determined (prior to expected laboratory testing) that the gliadin protein level is ~35% of this wheat’s overall gluten protein content. Wheat gluten’s insoluble proteins are gliadin and glutenin. This compares to ~80% gliadin protein levels found in a popular modern bread wheat variety that we last grew in 2003. Elevated gliadin protein levels are primarily what cause people to have allergic reactions/intolerances to most wheat.”
If anyone knows of a source for comparing the nutritional content of heirloom wheat varieties (or heirloom/ancient vs modern grains), I’d love to see it. I couldn’t find that, but I did find a guide for baking with various heirloom and ancient flours with info on water absorption, best uses, gluten strength, etc: https://breadtopia.com/newbies-guide-to-flour-for-bread-baking/