To receive an ordinary, unleavened Communion wafer, kindly wink your right eye as the minister approaches. For a certified, organic, whole-grain wafer, wink your left eye. For low-salt, low-fat bread, close both eyes for the remainder of the service. For gluten-free bread, blink both eyes rapidly while looking at the ceiling.Blinking aside, this isn't so far from reality in some places. Such announcements arise of course from the prevalence of coeliac disease, which is four times more common than fifty years ago, even taking into account different patterns of diagnosis and reporting. The reason for this new prevalence are not certain, but there is real suspicion that the kind of modern hard wheat we now eat in great quantity, and/or the presence of gluten and other wheat derivatives in other products, has triggered the spread of this auto-immune disorder. There are also much more common, if less critical, forms of allergy or intolerance to modern bread wheat found in a fair proportion of the population.
Anglicans can arguably consider gluten-free options for the Eucharist because the Prayer Book rubric states “it shall suffice that the Bread be such as is usual to be eaten” which allows alignment or correlation with cultural change; but it goes on to say “but the best and purest Wheat Bread that conveniently may be gotten”, both urging conscientious attention to the quality of the bread, and privileging use of wheat. What the tradition seems to have in mind is the desire to use what Jesus used at the Last Supper, instituting the Eucharist. The Lambeth Quadrilateral speaks of “unfailing use…of the elements ordained by him”.
Roman Catholics are officially less free about choosing Eucharistic bread. The General Instruction on the Roman Missal (2000) states: “The bread for celebrating the Eucharist must be made only from wheat, must be recently baked, and, according to the ancient tradition of the Latin Church, must be unleavened.”
The insistence that the bread be wheat, noted in both traditions if not held with equal insistence, may well be a historical mistake, if intended as strict imitation of the Last Supper, the accounts of which do not specify of what the bread was made. For that matter, the species of grain known in Jesus’ time are not the same ones we have today; wheat in particular underwent repeated hybridization even in the pre-industrial world, let alone after the more aggressive changes of industrial agriculture and recent plant science, now including genetic modification. So it is not even possible to know exactly what Jesus used, let alone use it.
In slightly later Rabbinic traditions and since, unleavened bread – matzah – is made from the same grains that are otherwise prohibited at Passover, because they create natural yeast cultures and leaven—and hence bread: wheat varieties, including spelt and emmer, as well as barley. In subsequent history, rye and oats have certainly been included in this obligation, although they may not have grown in ancient Judea. Some rabbis included rice. In fact yeast itself is allowed at Passover, since it is involved in the fermentation of wine; but while yeast-derived wine is allowed, grain-derived drinks like beer and whisky are not.
So although it is likely that the bread of Jesus’ Passover would have been made from an ancient wheat variety, it is not stretching things too far to say that other ancient Jews, and hence early Christians also, may have eaten bread made from any of these grains.
Why then the more restrictive view in Roman Catholic circles?
In the Summa Theologiae Thomas Aquinas argues not only from the superior quality of wheat, and from the awkward ground that Augustine of Hippo had viewed biblical references to barley - which was admittedly cheaper and coarser - as indicating the harshness of the Mosaic Law. This is a little ironic since the insistence on unleavened wheat bread is supposed to reflect the Mosaic Law too!
Thomas' prescriptive advice about wheat apparently carries more