One reason cookies spread: quick tip

Why oh why oh WHY did my beautiful sheet of chocolate chip cookies turn into a big, ugly blob as they baked?

Well, there are several reasons cookies spread.

A touch too much sugar, for one – sugar is hygroscopic; it absorbs liquid. When you’re preparing your dough, it may LOOK just fine (as the sugar is holding onto the liquid); but once it bakes, and the sugar releases that liquid it had been hoarding, watch out for those puddles!

Another less common reason is scooping cookie dough onto a hot baking sheet, or one that’s overly greased. The dough hits the hot/slick surface, and starts to spread immediately; the additional, planned-for spread in the oven is exacerbated by this head start.

Frank, our veteran chef and test kitchen baker, recently sent me photos from an experiment on cookie spread he’d just conducted.

Says Frank, “We’re working on different aspects of cookie baking, and thought you might enjoy these test results. The primary difference between these two trays [photos below] is the baking temperature.


One reason cookies spread: oven temperature

“The failed tray baked at 350°F for 14 minutes.


“For this practically perfect tray, we dropped the temperature to 300°F, and extended the baking time: 22 minutes for chewy, 30 minutes for crisp.

“This is a good example of showing temperature as ingredient.”

Why, exactly, does baking temperature affect cookie spread? And what can you do about it? Click To Tweet

Because the fat in cookies is a big part of their structure, prior to baking. Scoop the dough onto the baking sheet, and the fat is at least partially responsible for them holding their shape.

Once those cookies hit the oven, though, the fat starts to soften and melt. And the hotter the oven, the more quickly it melts. If the oven’s hot enough, the fat melts before the cookies set. And since their flour/liquid matrix hasn’t yet had a chance to harden, the cookies spread – becoming those dreaded cookie blobs.

This also might be one answer to a common question we hear on our baker’s hotline: “Grandma gave me the recipe herself; why don’t my cookies look like hers?”

The quirkiness of different ovens, especially those from different generations of bakers, notes Frank, is “one of the many dangers of believing that a handwritten heirloom recipe must be correct.”

Do you have a favorite cookie recipe that spreads too much? Try lowering the temperature, and baking the cookies longer; this trick just may give you the perfect treat you’re after.

PJ Hamel

PJ Hamel grew up in New England, graduated from Brown University, and was a Maine journalist before joining King Arthur Flour in 1990. PJ bakes and writes from her home on Cape Cod, where she enjoys beach-walking, her husband, two dogs, and really good food!


  1. Ruth

    My problem is the opposite. I WANT my cookies to spread more than they do. It’s just my preference, but that’s the way I like them. I haven’t been able to find a site that tells me how to do this.

    1. The Baker's Hotline

      Hi Ruth! You can always flatten them yourself before baking, but a common reason cookies don’t spread well is if there’s a little too much flour accidentally packed into the measuring cup while mixing the dough. This is very easy to do because flour likes to pack itself down so we recommend measuring by weight to prevent the problem entirely or, if measuring by volume is the only option, using the fluff, sprinkle, scrape method shown here. Another reason cookies won’t spread is if there’s very little sugar and/or very little fat, so it’s possible that it’s just the style of recipe that isn’t giving you the results you’d like. Annabelle@KAF

  2. Chris

    My mom went to college for Culinary and also worked as a school lunch cafeteria manager/baker. She started having trouble with cookies spreading to thin when baking and started troubleshooting as nothing had changed. Same oven, same ingredients, etc. What she found was that Parkay Margarine had modified their product so that it had a higher water content. She switched to Land O’Lakes margarine with a lower water content and that solved her problem.

  3. Megan Olson

    I made what was suppose to be gooey choc chip cookies. I followed the directions to a tee. Yet, they stayed in a heap, meaning they didn’t flatten at all. They baked in the same position they went in. They’re good, but not flat. What’s wrong? When recipes say “middle wrack: i’m using the third slip in the oven. I have six slips, so i imagine it’s the third for “middle wrack”. Am i incorrect? Checked the date of my ingredients and all show good to June 2019. Need someone’s help. This is becoming expensive for me.

    1. The Baker's Hotline

      The third rack sounds right to us, Megan! If you’ve made this recipe before and they spread, then there might have been more flour added this time. (It packs itself into cups so it’s a pretty unreliable form of measurement sometimes.) If you haven’t made this recipe before, it might just be the style of cookie that needs to be flattened before you put them in. Annabelle@KAF

  4. L

    I know this is an old post but I’m just seeing it now as im looking for tips on baking in a gas oven? The oven is insulated but not very much. Cakes come out fine but cookies always flatten once outside the oven 🙁

    1. The Baker's Hotline

      L, consider baking on a baking stone which holds a lot of heat and may give you a more consistent temperature and crispier results. Annabelle@KAF

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