We disclose a tablet containing at least one water-soluble fiber source, wherein the tablet is of a size and shape susceptible to insertion into a package of a beverage and the tablet will dissolve in the beverage in the absence of agitation in less than about 2 minutes. We also disclose a tablet containing at least one water-soluble fiber source, at least one acidulant, and at least one water-soluble carbonate or bicarbonate, wherein the tablet is of a size and shape susceptible to insertion into a package of a beverage. We also disclose a fiber delivery packet containing at least one water-soluble fiber source and a water-soluble film that encloses the at least one water-soluble fiber source, wherein the packet is of a size and shape susceptible to insertion into a package of a beverage and will dissolve in the beverage in the absence of agitation at a temperature from about 4° C. to about 25° C. in less than about 2 minutes. The tablets and fiber delivery packets we disclose are capable of adding flavor, sweetness, or tartness to bottled water and of allowing consumers to conveniently add fiber to their diets.