This comes from a question we received: “Why not use grape juice and a loaf of bread? Wouldn’t any liquid/solid food combo do?”
So once upon a time, I remember this theoretical coming up in conversation: What if I’m with a church group and all we have with us is some grape kool aid and some tortilla chips, can we have communion with that? It is actually a decent question at it’s base, although I don’t recommend any kind of communion service that is served with salsa. 
The goodness of this question is that it recognizes what is most important in communion, which is not the physical elements. Here at University Lutheran we reliably use Cavanaugh altar bread wafers and Manischewitz concord grape wine. The chapel at Concordia seminary gets locally produced wine hand delivered by a local farmer for Wednesday chapel (chapel communion is on Wednesday because it isn’t a worshiping community on Sunday). I have even heard of some churches celebrating New Years Eve with champagne communion wine. Some churches use loaves of bread leavened with yeast (there’s this whole argument about the yeast representing the Holy Spirit rising the bread/raising the Body), while others make a point of using unleavened. We could do things differently. We could spend a lot more on a bottle of wine than it costs to buy a bottle of Manischewitz, and we could probably get some artisan matzahs instead of our round discs, but that’s not what is important. What is important is that God is sacramentally unifying Himself with the elements for the purpose of unifying Himself with us in Christ. Which leads us to tortilla chips…
So if God is giving us Himself, His own flesh and blood, in the sacrament, then maybe we should pay attention to what He’s saying. And what He tells us at the institution at the last supper is that He is using bread (unleavened for Passover) and wine. And so while it’s not the most important part of the equation, it’s still a part of the equation. So that’s why we use what we use for communion. Even the “non-alcoholic” option has a few drops of real wine in it. So COULD God use grape kool aid and tortilla chips to get His Son to us? Sure, if He can promise that He can make stones cry out in praise if people don’t (Luke 19), then he could probably do salsa communion too, but let’s not make that decision for Him.
In fact, the “offertory” in many old liturgies used to include a family or a couple that would bring forth elements for communion. These would have been bread and wine that were painstakingly prepared for just this very purpose – so that God would be present among us in the sacrament. So instead of going lowest-communion-denominator with Jesus, let’s listen to Jesus and what He wanted His meal of remembrance and salvation to be about. And maybe if we do, it will change how we see that meal.