As Curtis explained, the history of rum in the New World got its start with Christopher Columbus bringing sugar cane to Hispanola in 1493, and luckily, this honeyed grass grows like crazy in the Caribbean. Sugar became king there and soon few other crops were planted; food and lumber often had to be brought in to the islands all at the expense of sugar. A key moment was when the molasses, the industrial waste product in sugar production, was no longer solely dumped into the ocean as people realized that it could be used to feed yeast in a ferment and then distilled. A second key moment was due to England colonizing Caribbean islands. While sugar was sent back to England and Europe, much of the molasses was shipped to New England in trade for food and other supplies. Over 160 rum distilleries sprang up in New England in addition to the ones further north in places like Newfoundland. England's hand in this trade caused rum to collapse after the Revolution.
A third key moment in rum was in the late 19th century when the Bacardi family came along and took the generally nasty, oily spirit and figured out how to refine it via filtration, better distillation, and other techniques. The 1950s unfortunately brought about the fourth key moment when rum became closer to vodka. America lost its taste for full flavored and funk in the age of processed foods and spirits that would leave you "breathless." Luckily, the fifth key moment was in the last 20 years with the rediscovery of what rum can be. In 1991, the Old New Orleans Rum Company started up and produced some intriguing spirits, and a few years later Phil Pritchard started in Tennessee.
Most New England rum was not considered as good as Caribbean rum (with a few exceptions). Wondrich surmised that the secret lay in Leonard Wray's (of Wray & Nephew Rum) Practical Sugar Planter book from 1848 with the quote, "Rum is the spirit which is made on sugar estates from the molasses and skimmings resulting from the manufacture of sugar." The secret here is the skimmings -- the foam on top of the boil that is removed; while not needed in the further production of sugar, it has a lot of the flavors of fresh sugar cane juice and can contribute a grassy note to rums. On the islands, rum was made from molasses, skimmings, and dunder (the remainder from the last still run), whereas in New England, they lacked the sugar cane and thus the skimmings and could only make "molasses brandy." Sadly, the Caribbean is making this same molasses brandy now since most of its raw materials are coming from Brazil. Therefore, the good news is that New England can be at parity with Caribbean rums, but the bad news is that there is no more terroir in much of Caribbean rums (at least the molasses-based ones where they are buying the raw materials at market). Campbell continued on the theme by describing how the Caribbean imports a lot of the raw materials for they produced too much rum volume to keep up on the agriculture end. Rum has often been quick, fast, and cheap, and its popularity post-World War II also saw the decline of flavor. "With the speed of molasses," there is a slow return to rum having more flavor, and this is getting craft bartenders excited.
Simo brought up a Camper English post on the Alcademics blog about how much sugar is added to rums -- a shocking amount! Eastern Standard bartender turned Privateer Rum rep Kevin Martin declared, "It's a bartender's job to add the sugar (to cocktails)." For example, Smuggler's Cove in San Francisco was mentioned for its immense sugar program where they carefully choose which sweeteners to mix with their spirits. So how does one know quality when there are few labeling laws as to additives? Campbell looks first for flaws; heads come across as nail polish burn and tails as pencil shavings, while level of sweetness suggests how much the producer is trying to hide these flaws. She also looks for quality: concentration and complexity of flavor, amount of heat, and whether it is still- or wood-derived for the variety of flavors.
While bartenders and rum aficionados look for such complexity, bar guests often look for sweetness. Unsweetened rum is often too harsh for tasting straight. Simo's reply was that, "'Ooh, that's smooth' is the worst tasting note ever" for it favors the bland and inoffensive. More flavor, for example, can be generated with longer, slower ferments, fermenting with dunder from prior batches, and fermenting to lower ABVs. The higher the alcohol content in the ferment, the more heads that get carried over; lower alcohol content is cleaner since the yeast are "less drunk" and produce fewer off flavors since they are less stressed. Rum is a lawless and rogue world; rum is made in too many places with too few laws and restrictions. As a counter example, Curtis mentioned Ed Hamilton's rums where the codes on the labels takes transparency to an extreme for it provides photos and details for each rum's production.
Wondrich brought up a point about a New England A.O.C. for rum that spanned the historic zone of Providence up to Portland. At the Boston Cocktail Summit in 2012, Wondrich and Curtis in the "Medford Gold" talk concluded that the new style of New England rum has the consensus flavor of molasses notes and a dry tang at the end, and that it should try to join the ranks of Bourbon in designation.