It’s a major frustration for many cooks, especially those whose family routines and work obligations make it desirable for them to prep-ahead some foods that are usually made just before serving. I’m talking about the annoying tendency of some foods to turn brown…
An Apple will always turn brown once cut – but you
can buy yourself a couple of hours’ time by
immersing it in Acidified Water.
I ran across a reference to Avocados turning brown in my daily food news scan this morning and decided to tackle the issue in a post. This is one that all culinary school students are exposed to in their theory classes, but it’s no mystery, and there are different ways to solve the problem. But it’s not just Guacamole and peeled Avocados that turn brown quickly even if they’re covered and refrigerated. Many white foods also turn brown or black after they’re peeled and exposed to the air. But why?
FAT TOM
This acronym stands for Food (type), Acidity, Time, Temperature, Oxygen and Moisture – the key factors that cause foods to spoil. And it contains the answer to our question about why some foods brown off.
Foods turn brown due to a combination of factors, not the least which is exposure to air. Delicate substances in the common Potato turn brown or black when exposed to oxygen, and the ghastly transformation takes place even faster depending on the temperature of the room where they are sitting. How can we use the FAT TOM acronym to formulate cures for the browning effect?
Potatoes
Here’s a simple case to start with; one that most cooks have experienced. You’ve peeled the Potatoes ahead and left them in a bowl. When come back an hour later top cook them, their surfaces have turned black. And it doesn’t matter if they’ve been covered and refrigerated. They’re perfectly alright to eat, but they look terrible and you’d never serve them. So, what do you do to avoid this situation another time? The Best way is to simply submerge your peeled Potatoes in cold water and cover the pot or bowl. They’ll last a couple of hours in that configuration without browning. And, if you’re going to boil or steam them, you can just add the Salt and turn on the burner when it’s time to apply the heat. We’re keeping the oxygen in the air away from them and keeping the temperature down – two of the FAT TOM factors addressed.
Commercial processors and some restaurants also use a chemical substance known in the biz as Spud White to counter browning. This is nothing more than a solution of Acid in cold Water which keeps the browning chemical reaction from occurring. You can make your own by adding a tablespoon or two of White Vinegar or Lemon Juice to 1 gal. / 4 L of cold Water in which you immerse your Spuds. Powdered Citric and Ascorbic Acid work, too, but are more expensive. The original formula for Spud White incorporated Sulphites, but it turned out a significant number of people were allergic to them.
Fruits
Apples, Bananas, Pears, Plums and Peaches are among the Fruits that tend to go brown if cut or peeled too long before serving. Acidified cold Water is the usual prescription for these Foods, too.
But one tip that can you time as well as protecting against browning is to mix them with Citrus Fruits or Pineapple. You may have been planning on doing this anyway if you were preparing a Fruit Salad or some Fruit mixture The acidic Juice from the cut Citrus will act like Acidified Water to protect the other Fruits from browning. Go ahead and add Sugar if that’s part of your recipe. It won’t impair the beneficial effect of the Acid.
Like Spud White, there’s also a preparation you can buy to combat Fruit browning, one brand name for which is Fruit Fresh. This stuff has the advantage that it won’t add an acidic taste to the food.
Whatever you use to treat your Fruits, remember that refrigerating covered can extend the time you’re buying before they go brown – which they eventually will, no matter what you do.
Avocados
These delectable, buttery babies get special mention because they pose special challenges. They’re exceptionally sensitive to browning. One source I’ve found recommends that you treat cut Avocados just like any other fruits that tend to brown. I’ve found that’s not always enough to protect this particular Fruit from browning.
This technique is the best I’ve found for cut Avocados: sprinkle the Avocado chunks or slices liberally with Lime Juice and toss to cover all surfaces of the fruit. Place the Fruit in a zip-closure freezer bag removing as much of the air as you can without damaging the Fruit, and refrigerate.
For Guacamole (see photo, top of page), if you must make it ahead, add the Lime Juice even before you begin to mash the Avocados so it mixes in well with the other ingredients. Then place the Guac in a small bowl or fridge container which add more Lime juice on top of the mix to form a thin but unbroken layer over the surface of the Dip. Then, press a layer of plastic wrap down on top of the Lime Juice expelling all the air. Snap the lid onto the container and place in he coldest part of the fridge for up to 2 hours before serving. Pour off the extra Lime Juice before serving.
So. there you have it…
Wade without fear or trepidation into the realm of Foods that tend to brown. You can win this battle…
~ Maggie J.