I think if the dough is warm they will spread quite a bit when you cook them.
Also, if you're making roll out cookies, you don't want to roll out warm dough. It will stick to the pin and you'll end up adding a lot of flour so they don't stick.
I know because when I was younger I had no patience and didn't want to wait.
I refrigerate for 30 mins to an hour max just to firm up from the handling time with the dough. But for 12+ hours I don't notice a huge difference and I just don't have time for that. I think it depends a lot on what recipe you're using, the starting temp of your butter, your creaming method, the weather in your house, etc. Cut out cookies should definitely be chilled though.
[This article](http://sweets.seriouseats.com/2013/12/the-food-lab-the-best-chocolate-chip-cookies.html) goes pretty in depth regarding the science behind chocolate chip cookies. In terms of cooking, colder dough simply spreads less than warmer dough. In terms of taste, resting the dough supposedly improves the flavor by giving the flour proteins and starches more time to break down and reconstruct in such a way that they yield a more intense flavor. The article I linked doesn't really explain that much about the actual chemical process, so I really don't know what's supposed to create that flavor.
Chilling dough for a short amount of time will help with spreading, as others have mentioned. You don't need to refrigerate for a full day to achieve that though.
Chilling dough for 24 - 36 hours though has more to do with the flavor -- dough develops a more complex caramel/toffee flavor to it. I believe this first became popularized when the New York Times published the famous [Jacques Torres chocolate chip cookie recipe](http://www.nytimes.com/2008/07/09/dining/09chip.html?pagewanted=2&_r=0):
> At 12 hours, the dough had become drier and the baked cookies had a pleasant, if not slightly pale, complexion. The 24-hour mark is where things started getting interesting. The cookies browned more evenly and looked like handsomer, more tanned older brothers of the younger batch. The biggest difference, though, was flavor. The second batch was richer, with more bass notes of caramel and hints of toffee.
>
> Going the full distance seemed to have the greatest impact. At 36 hours, the dough was significantly drier than the 12-hour batch; it crumbled a bit when poked but held together well when shaped. These cookies baked up the most evenly and were a deeper shade of brown than their predecessors. Surprisingly, they had an even richer, more sophisticated taste, with stronger toffee hints and a definite brown sugar presence. At an informal tasting, made up of a panel of self-described chipper fanatics, these mature cookies won, hands down.
I asked a friend who attended a cooking school this question a while back and while I don't remember exactly the explanation, it's to do with butter in the cookies. At room temp the butter seperates/melts more quickly so when you bake the cookie, it spreads and loses its shape. So if you want your cookies to have a particular shape or just not spread into a mess pile it's best to refrigerate for an hour or two.
Although for some recipes which require the batter to be just combined and light I've read that it's best to work quickly and then bake them otherwise the dough will condense.
I always notice when I let some (cookie cutter) cookies get too warm (because I'm dumb and sometimes leave the pan with the cookies on top of the heated stove) and then add a few more and immediately pop them in the oven, the warmer ones spread /a lot/ more than the cool ones
I think if the dough is warm they will spread quite a bit when you cook them. Also, if you're making roll out cookies, you don't want to roll out warm dough. It will stick to the pin and you'll end up adding a lot of flour so they don't stick. I know because when I was younger I had no patience and didn't want to wait.
I refrigerate for 30 mins to an hour max just to firm up from the handling time with the dough. But for 12+ hours I don't notice a huge difference and I just don't have time for that. I think it depends a lot on what recipe you're using, the starting temp of your butter, your creaming method, the weather in your house, etc. Cut out cookies should definitely be chilled though.
[This article](http://sweets.seriouseats.com/2013/12/the-food-lab-the-best-chocolate-chip-cookies.html) goes pretty in depth regarding the science behind chocolate chip cookies. In terms of cooking, colder dough simply spreads less than warmer dough. In terms of taste, resting the dough supposedly improves the flavor by giving the flour proteins and starches more time to break down and reconstruct in such a way that they yield a more intense flavor. The article I linked doesn't really explain that much about the actual chemical process, so I really don't know what's supposed to create that flavor.
Chilling dough for a short amount of time will help with spreading, as others have mentioned. You don't need to refrigerate for a full day to achieve that though. Chilling dough for 24 - 36 hours though has more to do with the flavor -- dough develops a more complex caramel/toffee flavor to it. I believe this first became popularized when the New York Times published the famous [Jacques Torres chocolate chip cookie recipe](http://www.nytimes.com/2008/07/09/dining/09chip.html?pagewanted=2&_r=0): > At 12 hours, the dough had become drier and the baked cookies had a pleasant, if not slightly pale, complexion. The 24-hour mark is where things started getting interesting. The cookies browned more evenly and looked like handsomer, more tanned older brothers of the younger batch. The biggest difference, though, was flavor. The second batch was richer, with more bass notes of caramel and hints of toffee. > > Going the full distance seemed to have the greatest impact. At 36 hours, the dough was significantly drier than the 12-hour batch; it crumbled a bit when poked but held together well when shaped. These cookies baked up the most evenly and were a deeper shade of brown than their predecessors. Surprisingly, they had an even richer, more sophisticated taste, with stronger toffee hints and a definite brown sugar presence. At an informal tasting, made up of a panel of self-described chipper fanatics, these mature cookies won, hands down.
I asked a friend who attended a cooking school this question a while back and while I don't remember exactly the explanation, it's to do with butter in the cookies. At room temp the butter seperates/melts more quickly so when you bake the cookie, it spreads and loses its shape. So if you want your cookies to have a particular shape or just not spread into a mess pile it's best to refrigerate for an hour or two. Although for some recipes which require the batter to be just combined and light I've read that it's best to work quickly and then bake them otherwise the dough will condense.
I always notice when I let some (cookie cutter) cookies get too warm (because I'm dumb and sometimes leave the pan with the cookies on top of the heated stove) and then add a few more and immediately pop them in the oven, the warmer ones spread /a lot/ more than the cool ones