No, Einkorn wheat is not gluten-free. Neither are other forms of ancient wheat.
Einkorn wheat (named from the German word "einkorn," which means single grain) is an ancient form of wheat. Two species of wheat are called Einkorn wheat: Triticum boeoticum, a wild variety, and Triticum monococcum, a closely-related domesticated variety. It's grown as a local crop in some areas of Europe, and will grow in some places where the soil is poor and other varieties of wheat will not grow.
Einkorn wheat, like spelt (another form of wheat), is used in baked goods mainly sold in natural foods stores. As in the case of spelt, some manufacturers erroneously place the term "gluten-free" on products made with Einkorn wheat.
However, foods made with Einkorn wheat still contain wheat (albeit in a slightly different form), and therefore are not gluten-free.
Several studies appear to confirm that ancient wheat strains, including Einkorn, Kamut and Graziella Ra, are not truly gluten-free.
For example, a study published in Clinical Nutrition in February 2013 tested four types of ancient wheat on small intestine cell samples from people with celiac disease. The study found the wheat strains all elicited immune system responses, although some people's cells reacted more vigorously than others.
A second study, this one published in the American Journal of Clinical Nutrition in 2012 looked at whether Einkorn wheat affected the immune systems of people with celiac disease in the same way as modern forms of wheat. The researchers found that the gluten in Einkorn is toxic to celiacs, but that it may be less toxic than other forms of wheat.
And finally, another study published in 2012 considered the ancient durum wheats Graziella Ra and Kamut. It also found that the gluten proteins in these forms of wheat caused immune system reactions in people with celiac disease. "In conclusion, we strongly advise celiac patients from consuming ancient wheats, including Graziella Ra or Kamut," the researchers said.
So the bottom line is: steer clear of these ancient forms of wheat, even if they're labeled "gluten-free."
Columba M.S. et al. Are ancient durum wheats less toxic to celiac patients? A study of α-gliadin from Graziella Ra and Kamut. Scientific World Journal. doi: 10.1100/2012/837416. Epub 2012 May 2.
Gianfrani C. et al. Immunogenicity of monococcum wheat in celiac patients. American Journal of Clinical Nutrition. 2012 Dec;96(6):1339-45. doi: 10.3945/ajcn.112.040485. Epub 2012 Nov 7.
Suligoj T. et al. Evaluation of the safety of ancient strains of wheat in coeliac disease reveals heterogeneous small intestinal T cell responses suggestive of coeliac toxicity. Clinical Nutrition. 2013 Feb 14. pii: S0261-5614(13)00049-6. doi: 10.1016/j.clnu.2013.02.003.