DHK said:
It was full of leaven (fermentation or yeast). It was symbolic of corruption, evil. This would never be used in the elements of the Lord's Table. Again it is blasphemous to do so. Corruption cannot represent that which is holy.
Blasphemous is a strong word. Are you really sure you want to use it? If so, you blaspheme, not me, because you think that wine containing bacteria (leaven) is pure, and purified wine is unclean. Even Welch understood the difference, which is why he attempted to purify the grape juice in some way other than that which produced alcohol.
Plus, you're going to have to paint with a wide brush -- you are accusing most churches of all denominations up until about the mid 1800s of blasphemy. They weren't serving Welch's grape juice, I can assure you that.
Most important, fermented wine is NOT full of leaven. That's the whole point. The bacteria/leaven eats sugar and produces alcohol as a by-product. It's a self-destructive process because once the alcohol gets to a certain concentration, it kills off the leaven and stops the process of fermentation. Fermentation is gone. It's over. Kaput. Done. There's nothing left to ferment. It's all dead. That's why the wine has become pure of any leaven.
No, the people of the NT didn't study microbiology. They didn't need to. God knows all. Plus, the correlation is fairly obvious since you can get sick from grape juice that simply goes bad due to the bacteria. But you won't get sick from fermented wine because the bacteria is dead and the alcohol prevents any other bacteria from growing. That's probably why they used to combine wine with water. That put enough alcohol in the water to kill off some of the bad stuff, but not enough to get drunk.
So while the people of the NT didn't study microbiology, you should study it if you think fermented wine is full of leaven.
FINALLY:
Puritan Increase Mather said, "Drink is in itself a good creature of God, and to be received with thankfulness, but the abuse of drink is from Satan; the wine is from God, but the drunkard is from the Devil."
From the 1689 Baptist Confession of Faith:
The Lord Jesus hath, in this ordinance, appointed his ministers to pray, and bless the elements of bread and wine, and thereby to set them apart from a common to a holy use, and to take and break the bread; to take the cup, and, they communicating also themselves, to give both to the communicants.
Please don't tell me that in 1689 they used the word wine but meant grape juice. Were all those nasty Baptists blasphemers? Even the Anabaptists served wine.
By the way, I'm pretty shocked that a moderator of these boards would be so loose with the claim of blasphemy. I thought that was the sort of thing you were supposed to prevent others from doing.