{"id":100,"date":"2020-04-27T10:41:48","date_gmt":"2020-04-27T14:41:48","guid":{"rendered":"http:\/\/blog.richmond.edu\/chemistryofcooking\/?page_id=100"},"modified":"2021-04-27T15:54:59","modified_gmt":"2021-04-27T19:54:59","slug":"dulce-de-leche","status":"publish","type":"page","link":"https:\/\/blog.richmond.edu\/chemistryofcooking\/lab-schedule\/lab-9-caramel-or-dulce-de-leche\/dulce-de-leche\/","title":{"rendered":"Dulce de Leche"},"content":{"rendered":"<p>Dulce de leche is a popular South American caramel sauce composed of only two ingredients: milk and sugar. In fact, the name literally translates to &#8220;milk jam&#8221; (side note: it is pronounced as &#8220;dul-say,&#8221; as opposed to &#8220;dul-che&#8221; &#8212; you&#8217;ll gain some cool points for this). According to\u00a0Alton Brown, dulce de leche most likely evolved as a way to preserve milk in the pre-refrigerator era. Though its flavor is complex and layered, dulce de leche is deceptively simple to make.\u00a0So how does combining milk, sugar, and heat turn into something as lucious and spoonable as dulce de leche? The answer lies in science &#8212; more specifically, chemistry. \u00a0<em>~ From Food52<\/em><\/p>\n<p>The\u00a0<em>Maillard\u00a0reactions<\/em>\u00a0are responsible for the browning of many foods including meat, the brown color on a loaf of bread, coffee beans, \u201ccaramelized\u201d onions and&#8230;.dulce de leche!.\u00a0<em>Maillard reactions<\/em>\u00a0take place between sugars like glucose and amino acids that are free or part of proteins. The\u00a0<em>Maillard reactions<\/em>\u00a0also require intense heat (250\u02daF\/120\u02daC) \u2013 but not quite as hot as the<a href=\"%24WIKI_REFERENCE%24\/pages\/caramel\" data-api-endpoint=\"https:\/\/muhlenbergcollege.instructure.com\/api\/v1$WIKI_REFERENCE$\/pages\/caramel\" data-api-returntype=\"Page\"> caramel forming reactions<\/a>. When we heat\u00a0milk and sugar &#8211; the proteins (remember, proteins are made of amino acids) in the milk undergo Maillard reactions with the sugar to generate nutty, complex caramel\u00a0flavors.<\/p>\n<h3>\u00a0<strong>Materials<\/strong><\/h3>\n<ul>\n<li>3qt saucepan<\/li>\n<li>large, sturdy spoon<\/li>\n<li>measuring cups (liquid and dry)<\/li>\n<li>measuring spoons<\/li>\n<li>wire mesh strainer<\/li>\n<li>kitchen thermometer<\/li>\n<\/ul>\n<h3><\/h3>\n<h3>Ingredients<\/h3>\n<p><strong>Makes\u00a01 cup<\/strong><\/p>\n<ul>\n<li><span class=\"recipe-list-quantity\">1\u00a0<\/span><span class=\"recipe-list-item-name\">quart whole\u00a0milk<\/span><\/li>\n<li><span class=\"recipe-list-quantity\">1\u00a0<\/span><span class=\"recipe-list-item-name\">cup sugar<\/span><\/li>\n<li><span class=\"recipe-list-quantity\">1\/2\u00a0<\/span><span class=\"recipe-list-item-name\">teaspoon kosher salt<\/span><\/li>\n<li><span class=\"recipe-list-quantity\">1\u00a0<\/span><span class=\"recipe-list-item-name\">vanilla\u00a0bean, split<\/span><\/li>\n<li><span class=\"recipe-list-quantity\">1\/4\u00a0<\/span><span class=\"recipe-list-item-name\">teaspoon baking soda.\u00a0<em>The baking soda keeps the milk proteins from coagulating too much and everything getting lumpy.\u00a0<\/em><\/span><\/li>\n<\/ul>\n<h3><span class=\"recipe-list-item-name\"><em>Instructions &#8211; READ FIRST<\/em><\/span><\/h3>\n<p><span class=\"recipe-list-item-name\">When you see the\u00a0<span style=\"color: #0000ff;\"><strong>boldface blue font<\/strong><\/span>, document that step with a photo on your blog<\/span><\/p>\n<p><span class=\"recipe-list-item-name\">The goal of this lab is to make\u00a0<em>two<\/em> dulce de leche sauces of different colors &#8211; one darker, one lighter. The color is a function of\u00a0<em>how long<\/em> the Maillard performing reactions are allowed to proceed. Read all the instructions first, and then decide how you are going to make your two different colored sauces<\/span><\/p>\n<p style=\"padding-left: 30px;\"><span class=\"recipe-list-item-name\"><em>Option 1<\/em> &#8211; run two saucepans side by side, and make two batches. Simple, but requires more resources<\/span><\/p>\n<p style=\"padding-left: 30px;\"><span class=\"recipe-list-item-name\"><em>Option 2<\/em> &#8211; cook one batch, then the second. Simple, but take a long time, as each batch is ~ 2 hours.\u00a0<\/span><\/p>\n<p style=\"padding-left: 30px;\"><span class=\"recipe-list-item-name\"><em>Option 3<\/em> &#8211; cook one batch, pour out some dulce de leche when the color is light, then let the rest keep heating until a darker color is achieved. Slightly trickier, but takes less time and resources.\u00a0<\/span><\/p>\n<p style=\"padding-left: 30px;\"><span class=\"recipe-list-item-name\"><em><img decoding=\"async\" src=\"http:\/\/www.seriouseats.com\/images\/2013\/11\/20131125-275032-dulce-de-leche-scratch.jpg\" \/><\/em><\/span><\/p>\n<ol>\n<li>Mix the first four ingredients together in a saucepan over medium heat until the sugar dissolves. Take off the heat.<\/li>\n<li>Stir in the baking soda, then put the mixture back on the stove over low heat. You want the mixture to bubble along the edges, but not to boil over.<\/li>\n<li>Let the mixture cook for 1.5 &#8211; 2.5 hours, stirring occasionally. Attach a thermometer to the pan so that the tip of the thermometer is immersed in the liquid (but not touching the bottom of the pan). Alternatively, <strong><span style=\"color: #0000ff;\">periodically measure the temperature starting when you first see the tan color, and then every few minutes thereafter until you have the color you want<\/span><\/strong>. <em>The color will begin to change\u00a0from white to tan after an hour or so, then will darken<\/em> <em>rapidly.<\/em> Keep a close eye on it now, stirring constantly. The longer the sauce stays on the heat, the darker it will get. \u00a0As the mixture darkens it will become thicker, and also nuttier. After your dulce de leche reaches your desired tone of caramel color, take it off the heat and let it cool slightly.\n<ul>\n<li><strong>You want two dulce de leche sauces of different colors &#8211; one darker, one lighter. If you are using Option 3 above, then pour or spoon some out into the strainer (step 4) when it has darkened only slightly, then let the remaining sauce darken further.\u00a0<\/strong><\/li>\n<\/ul>\n<\/li>\n<li>Push the sauce\u00a0it through a fine mesh strainer into a clean jar or bowl\u00a0by smoothing it against the wire mesh with the back of a spoon.<\/li>\n<\/ol>\n<p>Dulce de leche keeps, refrigerated, for up to four weeks. Eat it over ice cream, spread on toast, or right out of the jar.<\/p>\n<h3><strong>On your Blog<\/strong><\/h3>\n<p><span style=\"color: #0000ff;\"><strong>Take photos<\/strong><\/span><\/p>\n<ol>\n<li>Of your two batches of dulce de leche\u00a0(light and dark) side by side, close-up.<\/li>\n<li>Make a table of photos the temperature of your sauce and the color<\/li>\n<\/ol>\n<table>\n<tbody>\n<tr>\n<td>Temperature<\/td>\n<td>Photo of Sauce<\/td>\n<\/tr>\n<tr>\n<td><\/td>\n<td><\/td>\n<\/tr>\n<tr>\n<td><\/td>\n<td><\/td>\n<\/tr>\n<tr>\n<td><\/td>\n<td><\/td>\n<\/tr>\n<tr>\n<td><\/td>\n<td><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p><span style=\"color: #800080;\"><strong>Post a video<\/strong>\u00a0<\/span>in which you&#8230;<\/p>\n<ul>\n<li>Taste test the light and dark dulce de leches: The darker sauce\u00a0is supposed to be thicker and nuttier, while the lighter sauce is sweeter and thinner.\u00a0How do your sauces\u00a0compare?<\/li>\n<li>Describe what went really well during\u00a0your\u00a0dulce de leche making<\/li>\n<li>What would you change if you repeated this process again<\/li>\n<\/ul>\n<p><strong>Answer the following questions on your blog<\/strong><\/p>\n<ul>\n<li>Why is the darker\u00a0sauce less sweet?<\/li>\n<li>At what temperature did you see a significant change in color? Why is this significant?<\/li>\n<\/ul>\n<p>&nbsp;<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Dulce de leche is a popular South American caramel sauce composed of only two ingredients: milk and sugar. In fact, the name literally translates to &#8220;milk jam&#8221; (side note: it is pronounced as &#8220;dul-say,&#8221; as opposed to &#8220;dul-che&#8221; &#8212; you&#8217;ll &hellip; <a href=\"https:\/\/blog.richmond.edu\/chemistryofcooking\/lab-schedule\/lab-9-caramel-or-dulce-de-leche\/dulce-de-leche\/\">Continue reading <span class=\"meta-nav\">&rarr;<\/span><\/a><\/p>\n","protected":false},"author":1230,"featured_media":0,"parent":328,"menu_order":2,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"coauthors":[142150],"class_list":["post-100","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/blog.richmond.edu\/chemistryofcooking\/wp-json\/wp\/v2\/pages\/100","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/blog.richmond.edu\/chemistryofcooking\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/blog.richmond.edu\/chemistryofcooking\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/blog.richmond.edu\/chemistryofcooking\/wp-json\/wp\/v2\/users\/1230"}],"replies":[{"embeddable":true,"href":"https:\/\/blog.richmond.edu\/chemistryofcooking\/wp-json\/wp\/v2\/comments?post=100"}],"version-history":[{"count":2,"href":"https:\/\/blog.richmond.edu\/chemistryofcooking\/wp-json\/wp\/v2\/pages\/100\/revisions"}],"predecessor-version":[{"id":248,"href":"https:\/\/blog.richmond.edu\/chemistryofcooking\/wp-json\/wp\/v2\/pages\/100\/revisions\/248"}],"up":[{"embeddable":true,"href":"https:\/\/blog.richmond.edu\/chemistryofcooking\/wp-json\/wp\/v2\/pages\/328"}],"wp:attachment":[{"href":"https:\/\/blog.richmond.edu\/chemistryofcooking\/wp-json\/wp\/v2\/media?parent=100"}],"wp:term":[{"taxonomy":"author","embeddable":true,"href":"https:\/\/blog.richmond.edu\/chemistryofcooking\/wp-json\/wp\/v2\/coauthors?post=100"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}