I am wondering what ingredients do the Jehovah's Witnesses use in the bread and the wine. I talked to one of my friends who is a active member of the Jehovah's Witness religion but was not satisfied with her answer.
To find a proper answer to this good question, have a look at their 12/15 2013 Watchtower magazine. The paragraphs 5-7, under the subtitle 'The Emblems' should interest you.
As a summary, the bread was made from wheat flour and water, without any leaven or seasoning, such as salt, being added. Because it was unleavened, it would not have risen.
For the wine, as there was no need for augmenting or fortifying the value of Jesus’ blood, the wine used is not a type fortified with brandy or spices. Plain red wine should be used, a homemade wine or a commercial wine, such as Beaujolais, Burgundy, or Chianti.
We always mix wheat flour and water and fry it in a pan. The wine is what would have been available to them in Egypt, just a red grape wine, unadulterated thus reflecting the purity of Jesus' sacrifice.
It can be as simple as store-bought kosher flatbread and simple grape-based wine. The emphasis is on unleavened bread and the wine being a decent comparison to what was drank at the passover.