Until the mid 1800s, refined white sugar was a comparatively scarce & expensive luxury. Coarse brown sugar, molasses, sorghum & to a lesser extend, maple sugar & syrup were the sweeteners of the 'everyday housewife'. According to some old catalogues, syrup pitchers (called "syrups" for short) were originally called molasses cans, or syrup jugs. Syrups came in a variety of colorful containers in a different styles of glass products both blown & molded.
     Maple syrup, the sweetener made from the sap of maple trees, was first collected and used by Native American Indians, though was later adopted by European settlers. It is traditionally harvested by tapping a maple tree through the bark and into the wood, then letting the sap run into a bucket, which requires daily collecting. Molasses, sometimes called sorghum, is a thick syrup by-product from the processing of the sugar cane or sugar beet into sugar.
     According to Wm. Heacock in Victorian Colored Pattern Glass Book III, most colored glass syrups had metal tops applied to them with plaster. These tops were made of tin, pewter & other types of nickel or silver-plated metal. Frequently syrups are found today with a decomposed metal top or no top at all because that metal does not withstand the test of time as well as glass. This has created a need for metal tops to replace the missing ones. Whether a syrup has an original top or not is determined by 2 major methods. ... check for darkened plaster under the inner rim and/or compare the lid to an old ad or catalog reprint. Neither of these are fool-proof, however as there are always exceptions. In Heacock's (and our) opinion, as long as the syrup has a decent top on it, whether original, replaced or a reproduction, the value of the piece of glass which it caps should not be affected. Indeed many, but not all, of the the pieces shown in books have original tops. Even when the metal tops are original, it is not unusual for their 'thumb tabs' to have not made it through the years.
     During the 1850s to the 1870s syrups were always mold-blown & finding these in color is difficult. Later, pressed syrups were pressed from the bottom in an operation called the cut-and-shut method which was the only way a closed piece can be pressed unless the neck & lip are formed by hand.