Don't use flat crackers or hard tasteless little cubes or styrofoam-like, melt-in-your-mouth wafers for communion. Use bread—a normal, fresh, tasty loaf of bread.
Yes, use a nice loaf of yeasted bread. Normal bread with yeast is NOT leavened bread.
I don't know how many times I've had to explain this to visitors, especially Presbyterian visitors.
"Why don't you all use unleavened bread for the Lord's Supper?" they ask.
My answer: "We do. What you just ate is unleavened bread."
"But, but. . . it was not a cracker or a wafer, but a normal loaf of bread!"
"Yes, that's true. But it was not made with leaven, but with new yeast. Sour dough bread is made with old leaven. Ours was not."
Let's think about this a little more carefully.
1. The first thing to note is that the unleavened bread is bread made without the old sour "starter" dough that contains the yeast. In normal situations the yeast comes from that starter "leaven." "Leaven" refers to the old, sour reserved dough that contains the yeast. Leaven contains yeast. Leaven is not the same as yeast. Many translations completely miss the distinction.
2. When bread is being made, there are two sources for yeast. First, you can get yeast from the old leaven that you have "reserved." In fact, the yeast must be imported into the "leaven" at the start of the process. When the process begins yeast is cultivated from the lees of wine. Then the yeast is put into the dough. A portion of the dough is used to cook the first batch, but a larger portion is "reserved" in order have the yeast readily available for use in later loaves. This is what is called the "leaven." Today we call it the "starter" dough for sour dough bread.
3. The second way to get yeast is to get it "fresh" when it's cultivated from the wine. Technically, a fresh loaf of bread made with this newly cultivated yeast is NOT "leavened." What this means is that the first bach of yeasted, rising bread that is made with the new yeast is NOT leavened bread. It is yeasted, but not from the sour dough leaven. So technically speaking a loaf made with yeast NOT from the leaven is still unleavened bread. It's new. It doesn't use the old, sour stuff. The bread we use for the Lord's Supper in our church is not sour dough bread. It is not leavened bread. It contains fresh yeast. It is yeasted, but not leavened.
4. There was theological symbolism involved in the use of unleavened bread when the Israelites made their flight from Egypt. They left behind the old, sour world of Egypt and began a new life. It was called "the bread of haste" because they had no time to cultivate new yeast. The process takes time. So they had to eat unleavened and un-yeasted crackers.
5. Once they arrived in the promised land, they started over again with the yeast of God's new world. They would no longer get their "life" from Egypt, but now from the Lord's Spirit. They ate unleavened bread in the wilderness until they could get to the new land, harvest grapes, make wine, and also new yeast.
6. All of this has to do with the Old Creation. One cuts off Egyptian leaven and finds new leaven in the New Land. In between, one eats unleavened bread. The annual Feast of Unleavened Bread seems to be a week long return to the wilderness, the inbetween place. The association of leaven/yeast with the feast of Pentecost makes it clear that by that time new yeast has been found and is being used.
7. So, the general question is whether in the New Covenant we must reenact the history of redemption weekly or annually, or whether that would be the same error as transubstantiationism in the old sense. It seems to me that using unyeasted bread would be like doing animal sacrifices. It was part of what was done over and over until Jesus came and finished it. The new leaven each year gradually fell back and became Egyptian leaven during the year and had to be cut off anew at Passover. But the New Covenant is ongoing, and cannot fall back, because it is guaranteed by the death of Jesus, not by the death of animals. The Spirit-leaven of Acts 2 does not fall back and become Egyptian.
8. Now, if the leaven is thrown out and you are in haste to make bread, then it can be made without yeast. That apparently is what the Israelites did when they hurried out of Egypt. That's why that particular bread was called "the bread of haste." They left behind Egypt (the old leaven) and hurried out to cross the Red Sea. But there's nothing to suggest that we have to eat the bread of haste (unleavened AND unyeasted bread) at the Lord's Table. In fact, Jesus reclined at table and we relax for the covenant memorial meal. The old leaven is gone, so we don't eat sour dough bread. But we do eat newly yeasted bread that represents Jesus new kingdom and the life he gives us at his Table.
9. You should note also that in Israel the bread eaten during the Peace Offering was leavened or yeasted (Lev. 23:17). It is only Passover and the ensuing week that required unleavened bread alone be eaten, and that was not only during the special meal but at every meal for the week. After that, all the bread eaten, including at feasts and sacrifices, was yeasty and leavened. Leavened bread was offered at Pentecost, and leaven is thus associated with the coming of the Spirit, the Yeaster. We live after Pentecost. Go find Dr. Collins's article in the Westminster Theological Journal where he argues that the Lord's Supper is the fulfillment of the Peace Offering. The normal peace offering meal included yeasted bread. The one special one - Passover - did not in order to commemorate the Exodus.
A side note: not every reference to "leaven" in the Bible makes it out to be symbolic of evil or the old world. So the person who says, "I'm sorry, pastor, but I just can't eat this bread for the Lord's Supper because leaven and yeast represent evil in the Bible," is just plain wrong. Leavened bread was a regular part of the fellowship meals at the tabernacle and temple. Sometimes leaven (and the yeast it carries) even represents the healthy influence of the kingdom of God (Matt. 13:33). When you eat yeasty bread at the Lord's Table you are not symbolically ingesting evil. Sigh.
10. Oddly, we object to Romanists when they say (supposedly) that Jesus is recrucified in the mass. But then by using unleavened bread we are really doing something similar: returning to Passover, to the Old Covenant, over and over rather than worshipping in a post-Pentecostal way. I don't want to press this, but it makes sense to me.
So let's stop eating nasty little hard crackers at communion. What kind of feast is that? How can people "taste and see that the Lord is good" when they are wondering about just what that wafer that is stuck to the roof of their mouth is made of.