They teach the transformation is at the "substance" level, instead of the "accident" level. From one of the Wikipedia cited sources[1] > the "substance" of th

They teach the transformation is at the "substance" level, instead of the "accident" level. From one of the Wikipedia cited sources[1] > the "substance" of the bread and wine is changed by the power of the Holy Spirit into the "substance" of the Body and Blood of Jesus Christ. At the same time, the "accidents" or appearances of bread and wine remain. "Substance" and "accident" are here used as philosophical terms that have been adapted by great medieval theologians such as St. Thomas Aquinas in their efforts to understand and explain the faith. Such terms are used to convey the fact that what appears to be bread and wine in every way (at the level of "accidents" or physical attributes - that is, what can be seen, touched, tasted, or measured) in fact is now the Body and Blood of Christ (at the level of "substance" or deepest reality). This change at the level of substance from bread and wine into the Body and Blood of Christ is called "transubstantiation." [1]http://www.usccb.org/prayer-and-worship/the-mass/order-of-mass/liturgy-of-the-eucharist/the-real-presence-of-jesus-christ-in-the-sacrament-of-the-eucharist-basic-questions-and-answers.cfm http://www.usccb.org/prayer-and-worship/the-mass/order-of-ma...