By Rebecca Laroche, in consultation with Steven Turner
Some time ago, Steven Turner of the National Museum of American History and I published our discovery that Robert Boyle’s Experiments and Considerations Touching Colours (1664) reflected knowledge held in historical recipes. In particular, one experiment began with the observation, also recorded in recipes attributed to women, that syrup of violets and syrup of roses changed color when an acid, e.g. lemon juice, was added to it. The juxtaposition of this experiment with historical recipes has led to a second line of questioning, as Boyle begins the experiment with the direction to “take good Syrrup of Violets.” This phrase, coupled with the observations that there were many different recipes for the syrup (two manuscripts at the Wellcome Library have four separate entries), led us to ask what constituted “good syrup of violets” among the many kinds.
Indeed, the basic ingredients—violets, sugar, and water—show very little variation (excepting the addition of acid). One could argue that the recipes differ most notably in the amount of sugar relative to the violets, but the recipe texts also vary in the ordering of the process and the time of boiling the water (sometimes with the sugar). Many pointedly say to “make itt into syrup without boyling.” For example, this recipe held by Elizabeth Jacob (1654-c. 1685) repeats that it is the “best way not to boile the sirup at all,” ending with the direction “leting them come at the fire, w[ith] the flowers in spoiles the colour quite . . . if you will boile it be sure to leaue noe flowers in the Sirrup and boile it a little, though it is not the best way.”
Other recipes set flower juices, water, and sugar either in the sun, over low charcoals, or in a waterbath/double boiler, or they add boiling water to the flowers. These are all gentler ways of dissolving the sugar, while boiling the ingredients together would lessen the quality of the syrup.
In looking at the larger record, we observe a tension between preserving efficacy and color and the desire for a longer shelf-life for the syrup. Thus some recipes may attest for it lasting a whole year, but they also require the boiling of the sugar, water, and violet juice together. Two recipes juxtaposed, therefore, may on the left call for boiling all ingredients together, while on the right admonish to “be sure it doe not boyle.” Given an abundance of violets, the recipe maker is left with a choice: to boil or not to boil the flowers.
To anyone who has made preserves, this variation would make sense. Without refrigeration, a solution made with fresh flowers, sugar, and water would have lasted only a month or so, whereas the boiling together of all of the syrup’s ingredients meant a longer shelf-life (if sealed adequately). The downside of this shelf-life, however, would be the loss of freshness, and with that freshness the full medicinal and aesthetic benefits. Syrups infused with fresh flowers tasted better and had a more vibrant hue, i.e. more medically efficacious, thus not boiling the flowers was perceived as “the best way.” Clearly, the unboiled syrup was seen to have qualities special enough to sacrifice longevity. This may not be overtly articulated in every record, but it may be implicit in the juxtaposition of more than one recipe.
When we re-read Boyle’s experiment in this light, we see that it reflects these discernments. In specifying that it is “good Syrrup of Violets,” Boyle points to the syrup made “the best way.” Steve Turner puts the effect this way:
Above 212 degrees (F) some of the liquid inside the cells actually turns into a gas [and] this ruptures the cell walls. The process produces more juice than mashing them in a bowl, . . . But there is also a corresponding loss of flavor, color and chemical sensitivity the longer the Syrup is boiled. The Syrup lasts longer but isn’t as delicious or as sensitive. . . . The Syrup [doesn’t lose] all chemical sensitivity if it is boiled . . . but certainly the longer and more vigorously it is boiled, the more is lost.
The idea that a pre-scientific version of this knowledge is behind Boyle’s experiment is what led us to this juxtaposition in the first place. There are collective observations made in recipe-making that may not be attributed to any one individual but are rather shared in the transmission of one recipe by men and women alike.
 This entry builds upon Steven Turner and Rebecca Laroche, “Robert Boyle, Hannah Woolley, and Syrup of Violets.” Notes and Queries 58 (2011): 390–91. The research was in part made possible through a short-term fellowship from the Chemical Heritage Foundation.
 Wellcome MS 7818.
 Wellcome MS 7849/0032.
 Wellcome MS 3009/215. My thanks to Pamela Spangler for her help in sorting through the Wellcome online database in a timely manner.
 See, for example, Wellcome 7892/175.
 One non-boiling recipe at the Wellcome states that after “one month, or 6 week,” mold may start to grow. Wellcome MS 2330/4.
 Steve Turner, e-mail to Rebecca Laroche, February 6, 2011.