You can revive hardened sugar by placing the hardened sugar in the oven at 150 F to 200 F for around 15 minutes.
The heat from the oven will soften the hardened sugar although you need to use the hardened sugar as soon as it softens as the sugar will harden again after cooling off.
Sugar doesn't actually go bad like other foods and ingredients although sugar can become hard as it gets older but you can still break the hard sugar up and use it.
It is OK to use sugar that has hardened as hardened sugar is safe to use and does not mean the sugar has gone bad.
You can break the sugar up with a hammer such as a tenderizing hammer and then it will dissolve in liquids or you can also use the hardened sugar in baked goods or anything else.
Sugar hardens and can also become hard as a brick as a result of moisture and exposure to air.
Granulated sugar will harden and become hard as a brick when exposed to moisture and brown sugar can dry out and harden when it's exposed to air for too long.
If the bag of sugar is not fully sealed it can cause the sugar to dry out and harden.
Sugar can also become hard over time as a result of aging although moisture is the most common reason for sugar becoming hard.
You can use a hammer to break the sugar up and still use it.
Another way to quickly soften the hard sugar is to remove it from the package and place it in an oven safe container and heat it at 250 F.
Watch the sugar closely and turn the oven off as soon as it's soft and use the amount of sugar you need right away as the sugar will harden again as it cools down.
Sugar does not get moldy because sugar is actually resistant to microbial growth.
Sugar is a stable substance which does not harbor any bacteria or mold like other foods can.
The lack of moisture in sugar also deters the microbial growth.
Sugar actually has an indefinite shelf life and can last for decades.
Although sugar can become hard but it remains safe to use for years and you can break the hard sugar up and it will also dissolve in liquids.
While the sugar itself does not grow mold the sugar bag when kept in damp locations can grow mold.
Granulated sugars can also become harden or lumpy and sugars in honey and syrup can also crystalize.
Even when the sugar has become lumpy or crystalized it still is safe to eat consume the sugar.
The best way to store sugar is to store the sugar in a cool, dry airtight container in an odor free location.
Store the sugar in a cool, dry place such as the pantry and away from any extreme temperatures and sources of chemicals and use a container with a tight fitting lid to prevent bugs from getting into the sugar and clumping.