Brown sugar should be stored in a cool, moist area in a rustproof container with a tight-fitting lid. Brown sugar can also be stored in any type of re-sealable, moisture-proof plastic bag. The quality of brown sugar is best when consumed within six months of purchase and opening.
Airtight Container
The best way to keep brown sugar soft is to store it the right way from the get-go. As soon as you open up the bag, empty the contents into an airtight container. This will keep air from getting inside and drying out the sugar.
A piece of unglazed food-grade terra cotta makes for an ideal brown-sugar saver. Simply soak that piece of pottery in water, then drop it into the brown sugar container. Apply the lid and then walk away. Your brown sugar will be perfectly soft and fluffy the next time you reach for it.
Per Home Cook World, cool and dry means a room temperature ranging from 68 degrees Fahrenheit to 77. Conversely, a refrigerator is set to run below 40 degrees, which is low enough to harden brown sugar. The appliance's internal humidity is also a problem.
Just make sure the container is airtight. Next, put a marshmallow in the container. This will keep the brown sugar soft, owing to the moisture in the marshmallow. You can also use a slice of white bread, or a couple cut-up wedges of apple, both of which have enough moisture to do the job, too.
Polyethylene bags, Mylar-type bags, food-grade plastic buckets, glass canning jars, and #10 cans are all suitable for dry sugar storage. Glass canning jars and #10 cans work best for liquid syrups and honey. Removing oxygen for long term sugar and honey storage is not required and not recommended.
Similar to other types of sugar, brown sugar can last indefinitely as long as it's not exposed to air and moisture, and bugs are kept away. Some manufacturers include a two-year best-before date after opening. Brown sugar won't go rancid after two years, but there will be a slight change in its taste and texture.
To keep air out, simply store your Brown Sugar in any airtight container. Your best options are glass or reusable plastic containers with locking and sealing lids. If you don't have a container large enough, a sealable, freezer-safe bag will do.
Brown sugar essentially does not go bad (unless contaminants have gotten mixed in), making it ideal for buying in bulk, if you do a lot of baking. Hardened sugar isn't bad. It's just in need of moisture. However, brown sugar will perform best if used within two years of purchase.
Place a small piece of bread in the container with the brown sugar. Like marshmallows, white bread contains a good amount of moisture. As that transfers to the molasses in the brown sugar, the bread will become hard, the brown sugar soft. Replace that piece of bread weekly, or as needed.
Freezer. Storing your brown sugar in a sealed bag in the freezer can help lock in moisture, some cooks say. Just be sure to let it come to room temperature at least 15 minutes before you plan to use it.
If you buy a big bag of brown sugar when it's on sale and you know you won't use it quickly, you might wonder whether you can freeze it. The answer is yes.
Yes flour can absorb smell from the air, as well as the container in which it is stored. It is for this reason you should always store flour in an air tight container that is free from smell. BPA free, food safe plastic or glass is a good option to protect flour from absorbing odors.
Granulated sugar loses its quality when exposed to humidity, but brown sugar hardens when air enters the container and makes it lose moisture. If possible, store it in the retail plastic bag as it won't let it dry. An alternative can be a ziplock bag, and as you close it, remove as much air as possible.
Sugars are best stored at room temperature in an airtight container. Granulated sugar may form lumps, but they are easy to break up with a whisk or fork. Brown sugar is especially prone to hardening, in which case you'll have to soften it before measuring and using in a recipe.
Just place your block of brown sugar in a microwave-safe bowl. Wet a paper towel and squeeze until just slightly damp. Lay the paper towel over the brown sugar and microwave it in 20-second intervals, loosening the sugar with a fork between each interval, until the sugar has returned to its normal texture.
Dried-out, rock-hard brown sugar happens to the best of us, and we're all familiar with the classic tricks recommended to get it soft again: stick a slice of bread or an apple wedge in the bag, and osmosis will kick in overnight.
Granulated sugar will harden when exposed to any type of moisture. Here is an easy way to make hardened granulated sugar soft again -- Preheat oven to lowest temperature, 150-200 degrees. Remove sugar from the package and put in an ovenproof container that will hold the sugar.
Even though the shelf life of brown sugar is indefinite, it's best to use it within two years of purchase for maximum flavor. Don't store brown sugar in the refrigerator. However, if you are in a very dry area or are going to keep it for a long time, you may want to freeze it.
Over time, even in an airtight container, brown sugar can harden and/or start to turn white (as the sugar dries, some of the molasses separates. Creating a humid environment will allow the brown sugar to rehydrate to become pliable and brown.