“Gravy Day” is a relatively new date in the Australian calendar. Paul Kelly’s song How to Make Gravy tells the story of a prisoner (Joe) writing to his brother on December 21. Joe laments missing the family Christmas celebrations and asks who will make gravy for the roast lunch in his absence.
While a roast may not be everyone’s idea of the perfect Christmas feast, “Gravy Day” does give the opportunity to discuss the chemistry involved in making gravy – a thickened sauce made from drippings collected from roasted meats.
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Give my love to Angus (beef?)
Roasting meat sets off a cascade of chemical reactions, producing myriad new flavour chemicals. More than 1,000 flavour compounds have been identified in roasted meats.
Each chemical gives its unique characteristics to the taste and smell of the finished roast. The chemical 12-methyltridecanal helps give roast beef its “beefy” flavour, while the sulfur-containing compound 2-methyl-3-furanthiol is more often found in roast chicken.
There are three main types of chemical reactions taking place when roasting meats that produce flavour chemicals.
The Maillard reaction is responsible for both colour and flavour. This broad reaction type takes place between amino acids from the protein and sugars and simple carbohydrates found in the meat.
The Maillard reaction is also the chemistry responsible for many favourite flavours, including roasted coffee, chocolate, steak, toast and more.
A hundred degrees, even more maybe
The other main type of reaction occurring in a hot oven is the breakdown of fats by “lipid degradation”. This can form hundreds of different chemical compounds. Many of these chemicals are described as “fatty”, “tallowy”, or smell like fried foods.
The unique fat profiles found in different animals translate to the profile of flavour chemicals that form from lipid degradation when roasted. Further flavour compounds can arise through the third type of reactions combining products of Maillard reactions and lipid degradation.
One specific flavour compound identified as having a “gravy aroma” is known as 3-mercapto-2-methylpentan-1-ol. This compound comes from roasted vegetables, so including some veggies in your roasting pan will give you more depth of gravy flavour. Also, “cutting onions” is a useful excuse if listening to How to Make Gravy gets you feeling emotional.
Roasting meats causes the fats to “render” and separate from the meat as a liquid. The fat pools in the tray with flavour-rich meat juices.
While the fat and the water both carry flavour compounds, too much fat can give the finished gravy an unpleasant mouth feel, or can separate into layers when served.
It’s worth pouring off the pan juices into a jug to allow the fat to separate from the liquid so you can control how much fat you’re adding. Be sure to dispose of the excess fat responsibly – don’t pour it down the drain.
Just add flour…
Flour (or, more specifically, starch) is the secret ingredient of a good gravy. Starches are large complex chemicals that are made up of lots of sugars joined together.
Starch granules are tightly packed and swell greatly when they absorb water. The swollen starch molecules forms a gel-like network that traps water and oil to give a thickened gravy.
Wheat flour is most often used as the starch source. Corn and arrowroot starch can also be used. They have a higher percentage of starch than flour and a more neutral flavour.
Wheat starch typically requires a larger quantity to be added and longer cooking to form a paste. Whichever starch you use, don’t add it too quickly or without mixing as you’ll form lumps.
…salt, red wine, and a dollop of tomato sauce
Salt is a common ingredient when preparing roast meats, both on the surface of the meat to draw out moisture and as a flavouring agent. The pan juices are typically concentrated as part of the gravy making process.
Make sure you taste the gravy before seasoning, as salt will be concentrated by heating.
Additional flavour components can be introduced by adding red wine, sherry, stock, or tomato sauce. These ingredients will broaden the flavour profile through sweetness (sugar), acidity (vinegar, citric and malic acids), and umami in the case of tomato sauce (natural glutamates, such as those found in MSG). Some folk even add Vegemite to their gravy for an extra umami boost.
I bet it will taste the same
If you happen to have screwed up your gravy this time, or are after convenience, then you can turn to an instant gravy powder. The main ingredient is typically maltodextrin or another corn-derived (and possibly chemically modified) starch.
Shelf-stable powdered fats, salt, colours, and a range of flavour additives will be present in varying amounts depending on the style and price point of the product.
The advantages of the instant version are speed and uniformity due to the carefully controlled commercial production.
So unlike Joe’s concerns for his family’s gravy, an instant gravy will be more likely to taste the same, regardless of who ends up making it.
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In the case of gravy it's fat and water. Water sticks to itself very well so when you mix water and oil the water sticks to itself and doesn't mix with the oil. An emulsifier is a chemical which can grab the water with one end and the fat with the other and make them get along.
A traditional roux uses roughly an equal amount of flour and fat, but gravies often call for a bit more flour than that, to ensure the gravy is thick enough. (The classic ratio for gravy is three:two:one, so 3 tablespoons flour, 2 tablespoons fat, and 1 cup of hot stock.)
(You can also start with a slurry of flour and water—equal amounts flour and cold water whisked together—if you want.) Whisk the gravy while slowly adding liquid: Slowly add stock, water, milk, cream, or a combination to the pan, whisking vigorously to dissolve the flour into liquid.
Any cooking you do involves chemistry. The use of heat, cold, and cutting changes the composition of foods. Even simply slicing an apple sets off chemical reactions that change the color of the apple's flesh. If you heat up sugar to turn it into syrup, you're using a chemical reaction.
Finish your gravy by adding a tablespoon of lemon juice. This might seem like a strange addition, but the acidity works to bring out all those delicious flavors in the gravy. If you don't have lemon juice on hand, a splash of apple cider vinegar or white wine vinegar will work just fine.
If your gravy is on the skimpy side, you can thicken it quickly with flour or cornstarch. But don't add your thickener directly to the gravy, which will create lumps. Instead, try stirring in three or four tablespoons of flour or cornstarch into a small amount of cold water until you have a smooth paste.
Another way to thicken gravy without flour is to roast vegetables like carrots, onions or shallots, celery, whole garlic and red bell peppers with the meat. Strain the juices and puree the vegetables and add it to the de-fatted meat juices, wine and some stock. Reduce the liquid to a thick gravy then strain and serve.
Let me assure you, the process of making gravy really isn't hard. You just have to focus on the task and not let anything distract you while making it. Successful gravy is one that is smooth and silky, not lumpy, and it doesn't have the flavor of uncooked flour.
If the gravy lacks oomph, adjust seasoning as necessary with kosher salt and freshly ground pepper. If you used canned stock instead of homemade, the gravy might not be as flavorful. Homemade stock, even made with chicken stock rather than turkey, will produce a superior gravy—so it's worth the effort.
Cornstarch should thicken gravy in less than a minute when at a simmer. If it doesn't thicken enough, it's a sign that you need more cornstarch. Whisk in more cornstarch slurry a little at a time, and let each addition come to a simmer before adding more.
It could be made halal and there might get even be restaurants making halal poutine. However the gravy used to make poutine is usually made with meat (either beef or chicken) so unless halal meat is used to make the gravy it's not halal.
Why does my gravy have a jelly-like texture? Gravy gets a jelly-like texture due to too much thickener. Too much flour, for instance, can result in a gummy consistency (particularly when left overnight in the fridge). Reheating with additional liquid can often help soften things up.
1/3 cup should be plenty per person. On the contrary of gravy, cranberries are something that I seem to think just get better the longer they sit. 1/3 cup per person is plenty, but don't be too disappointed if you have leftovers.
A roux works thanks to the thickening power of starch. Starch is made up of minuscule granules, each of which contains two different forms of starch molecules. First are the long, thin chains of glucose known as amylose; the second are branched clusters of glucose known as amylopectin.
Incorporating a touch of sweetness into your gravy can help balance out the salty flavors. You'll need to add a small amount and taste as you stir so that the gravy doesn't become too sweet. Try adding a spoonful of either sugar or honey to salty gravy. Stir, taste, and add more if necessary.
In a medium bowl, combine the milk powder, flour, bouillon granules, instant minced onion, thyme, onion powder, marjoram, and pepper. Stir with a wire whisk to blend thoroughly. Use a pastry blender or two knives to cut in the butter until butter is evenly distributed and particles are fine.
Similar to flour, cornstarch is another ingredient that can be used to make gravy thicker. With cornstarch, making a slurry is also an option, but with 1 tablespoon of cornstarch whisked into cold water. Again, you'll want to add the slurry in increments so you don't over-thicken the gravy.
Introduction: My name is Chrissy Homenick, I am a tender, funny, determined, tender, glorious, fancy, enthusiastic person who loves writing and wants to share my knowledge and understanding with you.
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