When you're making an all extract brew, you don't need to sacrifice body and mouthfeel.
Maltodextrin (Dextrin, Dextrine) is good for adding mouthfeel and body to extract brews without affecting flavor. You add it to the wort at the same time as the extracts. Maltodextrin is naturally present in finished beers, up to 6% by weight. Maltodextrin is not fermentable by brewer's yeast so adding it to increase body will not increase the alcohol content.
Our maltodextrin is composed of .5% dextrose, 2.5% Maltose, 3.5% maltotriose, 93.5% higher saccharides, and is made from corn. It is also available by the pound or even the sack.