white sugar clumping

Clumped Sugar – Why, and How to Keep it from Clumping

Sugar will last indefinitely. That is, it’s shelf life is forever. However, there’s a problem I’ve had in the past… Clumped sugar. So how in the world do you keep it from clumping?

First, I’m into practical prepping and preparedness. Although we don’t consume much sugar anymore, it is one of the many dry food staples that we’ve stored in bulk. Not only does it provide extra, but food prices always go up, right? So it makes good common sense.

Anyway, I have stored white sugar in a 5 gallon bucket (actually two). We had purchased bulk bags and dumped it in until full.

We use Gamma Lids on these for convenient access (and some of our other accessible food storage too).

The problem has been after awhile (not exactly sure how long it took) the white sugar got hard. In fact it can get very hard indeed! I’ll give you some suggestions how to “un clump” the sugar in a minute…

How to Prevent White Sugar Clumping

So, why is the sugar clumped? How to prevent it from clumping in the first place?

Unlike brown sugar, white sugar seems to be pretty dry. I didn’t think it would be a problem. But here’s what I believe happened.


The 5 gallon storage buckets with sugar inside were on a concrete floor for quite awhile.

I believe the cool concrete floor created a seasonal temperature differential, transferring into the bucket. This may have instigated just enough condensation inside to begin the sugar clumping.

I have learned the lesson to isolate any food storage from concrete, thus avoiding this potential temperature difference. Nowadays I’ll use wood, and I also use some of that foamboard insulation (even better!) that comes in 4×8 sheets, and easy to cut/slice with a long blade razor knife.

Anyway, do any of you have a trick or two to keep white sugar from clumping?

I await your comments…

How to Un-Clump White Sugar

I had to chip away at it. It took a good amount of effort to break the top layer into chunks.

Food Processor

Unclump? De-clump? Whatever you call it, I used a food processor.

Mrs.J’s Cuisinart ‘Pro Classic’ food processor worked well. I kept pulsing it on and off, and then let it run steady for a bit. This process brought it back to granulated sugar (with some powder too – given the food processor action).

But that’s certainly all a pain…

Use the Oven

Domino Sugar says…

“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.
  • Place in the warm oven for approximately 15 minutes.
  • Tap sugar with a spoon. If it starts to fall apart, turn oven off and leave sugar in the oven for an hour or two to completely dry out.
  • Always store granulated sugar in an airtight container.

Note: I’ve tried this with severely chunked up sugar and it partially worked. Maybe if your sugar isn’t too severely clumped, it will work well.

Crackers (or bread)

“It was a common practice to add a saltine cracker to the sugar canisters in restaurants to prevent the problem. If you did eventually have a little clumping, it was time to replace the cracker.”

Keep Brown Sugar From Clumping

This problem seems to be unlike brown sugar. To prevent brown sugar from clumping you actually add some moisture (those brown sugar bears for example).

Or, to unclump brown sugar in a hurry, put it in the microwave. You can add a small bit of water in a separate bowl to create moisture in the microwave.

how to keep sugar from clumping

[ Read: Foods That Will Last Forever – Indefinite Shelf Life ]

[ Read: Gamma Seal Lids – And Here’s Why You Want Them… ]


  1. We store sugar the same way, but altho it does clump together. It has never gotten that hard. Ours is stored in an unheated shed. We only buy sugar twice a year.
    I wonder if you put an old butter bowl with rice inside, maybe with a few small holes punched in the lid?

  2. Sugar clumping into lumps was a common problem in East Texas when I was a boy.

    It was a common practice to add a saltine cracker to the sugar canisters in restaurants to prevent the problem. If you did eventually have a little clumping, it was time to replace the cracker.

    I have seen the heating work, in fact I have used it for a five pound bag that got set on a storage shelf in a dark area and forgotten about. It worked fine for me.

    Personally, I was amazed that the mice didn’t get to it. (My grandmother’s house when I was about sixteen or so.) I am trying it just now with a bag from the other house that was left in a plastic tote and is now solid, I put it in the back window of an auto that is not running at the moment to heat during the day and dry out at night. (West Texas doesn’t have high humidity often) It’s been there a week and is already softening up. I will probably finish it in the oven, but that’s a bag that didn’t get wasted.
    – Papa S.

  3. I just made cookies today. When I opened my brown sugar, it was a solid lump. I broke off pieces and put them in my blender. Got most of the lumps out and put the fine particles through a sieve. Those few lumps remaining went back into the jar with the other lumps to be blended again next time.

    Worked great.

    1. DaisyK—with brown sugar (no idea if works with white), if there are lumps, toss in a piece of bread (white usuall), or piece of apple. Works a treat.

      1. Jane,
        I have heard about the bread. But I was ready to bake and didn’t have time. I would think blending would work better with white sugar.

        1. Daisy K & Jane Fox
          Restaurants used soda crackers in the sugar jars on the tables, and my mom passed this hint on to me.
          If you are out of brown sugar you can make your own, by mixing white sugar with molasses until you have the blend of brown sugar you will require for a recipe.

      2. Bread or crackers will do the trick. If you intend to use the sugar immediately, it doesn’t matter which you use. But there is a difference in long-term consequences. Whereas crackers are made with baking powder, bread is made with yeast and will contain yeast and mold spores. You will not want these in your sugar, if it is to be stored.

  4. We store our long term white sugar in 5 gallon buckets with a desicant and a standard lid. Long term sugar is stored in the basement around 54 degrees.Our daily use sugar is in a 5 gallon bucket with a gamma lid .We keep all buckets off the floor with 1/2 ” OSB underneath.We have experienced minor clumping, but nothing to bad.

  5. Wow I miss sugar. hahaha. I will have to check and see if I can safely store my sweeteners I can have. I am using erythritol right now. I can’t even begin to think if I can store that in bulk.

  6. I was advised early on, that no containers should ever touch the concrete because the cooler temperature can cause moisture to form in your container. If you do not have a low shelf to place it on, make sure to put a couple layers of cardboard under the container. I have had sugar that was not yet transferred out of the bag and into containers harden on me when stored in the basement.

    It wont be fun to try to soften the sugar without electricity so we better figure it out now. Otherwise, think about storing sugar in places that won’t have extreme temperature or moisture issues.

  7. When I have wanted to unclump brown sugar in a hurry, put it in the microwave. You can add a small bit of water in a separate bowl to create moisture in the microwave. Otherwise I use the little bears, but sometimes I don’t pay attention to how long it has been since I soaked it. I actually use brown sugar more than regular sugar though so not too often that I have to unharden brown sugar.

  8. Matt, you might want to check out one bag of your sugar stored with O2. I read way back when that we should NOT put the O2 absorbers in when storing white sugar. It said it would cause it to turn into a brick.

    1. DAMedinNY

      That information about the 02 is correct. I put my sugar in Mylar bags then fold the Mylar over and do not seal it.

  9. I no longer have a problem with white sugar or white sugar with molasses added to make it brown. I gave up sugar in favor of honey and have no regrets.

  10. Well heck. I just put it in a bag and smack it with the side of the hammer.

    1. Chevy
      I have vacuum sealed brown sugar, as for white sugar you would need a cut coffee filter. The filter is used to keep the fine sugar dust from stopping the sealing process. Some times you have to blow the vacuum line, and then I reverse the lines from the cap and the machine. It works do not ask me how or why.🤔

  11. I put a broken piece of unglazed clay flower pot in with the sugar and have never had a problem with clumping.

  12. Sugar has a lot of uses such as curing meat, stopping infection in wounds, mixing with borax for ant bait. I would hate to waste my honey, which is more costly, for some things. I still make some recipes with sugar, but have changed many over to brown sugar or honey.

  13. I never had a problem with my white sugar clumping until I moved to Florida from Pennsylvania. I used a meat tenderizer mallet to make it usable last night when I was making snickerdoodles. The cookies didn’t turn out right and I’ve never had a problem before. They came out hard and flat. So the sugar didn’t act the same way after it was unclumped.

    1. Carol A
      My mom showed me a way to stop this from happening. The restaurants would place a single cracker inside the sugar container, it would prevent the clumping process. Every so often you replace the cracker to prevent this from occurring.

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