This seems like an easy enough question, but the SDMB search doesn’t seem to bring anything. Here goes:
What’s the difference between using warm, room-temperature butter and cold butter when making pie crust? Let me tell you what we did, and maybe you can tell me if warm butter was the culprit?
Two weeks ago, my wife and I made apple pies (had to use our orchard apples up). Following the instructions for the pie crust from foodtv.com, we made the pie crust – lotsa flour, butter, some sugar, and a bit of salt. The instructions said to use COLD butter, which we did. Instructions kept saying to re-refrigerate if the dough got warm, which we did. Everything worked well. Specifically, we could roll the dough on the countertop, and pick it up.
Last night, we repeated the pie experiment. I’d already warmed the butter (softened, not melted) when I caught the instructions to use COLD butter. Oh well, I thought, what’s the difference? (Really, what IS the difference?). We did everything else right though, including letting the dough get very cold before rolling. HOWEVER, when we rolled the dough, we couldn’t pick it up at all without it breaking apart. Agh! We eventually rolled it on wax paper and got everything to work, but our early encouragement suffered a setback after last night.
Any ideas? Was it the butter temperature? Why?
Funny, I just made a pie crust tonight…
When you use cold butter, the butter breaks apart into little peices throughout the flour–they basically stay separate. When you use warm butter, the butter kind of melds with the flour. I suppose that could lead to your problem. Perhaps there was a bit too much moisture in it the second time.
Using cold butter leads to a flakier pie crust. THe little bits of butter melt away in baking, leaving little pockets. That is the flakiness.
I think Green Bean has the right answer, but to just add some anecdotal evidence-- when my dad makes a pie, he freezes the butter and grates it into the flour. And the crusts are kick ass.
Using soft butter will result in a “short” pastry (i.e, one that won’t break into large flakes after cooking). That’s not necessarily a bad thing, but I have always found short pastry to be much harder to shape. Bernard Clayton in The Complete Book of Pastry has several recipes for long-, medium-, and short-flake pie dough. He typically recommends that the dough be refrigerated for 4-24 hours after mixing and then left at room temperature a half hour (for medium-flake dough) or a full hour (for short-flake dough) before rolling out. The room-temperature rest really does seem to make the dough easier to shape.
I think this has already been said, basically, but I’ll restate it in my own inimitable way: Cold butter stays in little pieces rather than being homogenously incorporated into the dough. Then when you bake it, the little bits of butter (which, remember, have been mooshed flat by being rolled out) cause sepearate the dough into highly desirable flakey layers. This is why recipes call for cold butter.
My WAG is that the problem you had handling the dough was because, while the recipe called for cold butter, you used warm butter, which has quite a different texture. Maybe the problem was moisture, or the butter fat being distributed throughout the dough instead of being in little pockets surrounded by sticky/wet flour, or something like that.
Disclaimer: I have always had excactly zero luck with pie dough–I always manage to get it stuck to the rolling surface, and rip a big ol’ hole in the middle. So I’m just regurgitating what I’ve read, here, not giving any practical advice.
Thanks all! Those explanations seen to make a whole lot of sense.
I’m pleased to see that from BigDaddyD that I’m not the only male the bakes pies at home. 
The dough really was hard to handle with the warm butter. But I think I like the end results a lot better. I’m not really too keen on “flakey” crust. Having used the warm butter, the crust came out almost cookie-like. I loved it, and it tasted great!
On the other hand, I’m curious about grating frozen butter and trying it. Maybe we’ll give that a try next apple season.
Thanks again!
Well, like bibliophage said, that’s because the warm butter resulted in a short crust. (like shortbread) If you prefer that, you might want to find a recipe for a short crust instead of just using warm butter in the regular recipe. I like a short crust, too, for certain kinds of things–especially fruit tarts.
No need to grate the butter. You can combine the dry ingredients with chunks of butter in the food processor, and it will come out perfect. I use the recipe in Bittman’s How To Cook Everything. It is so incredibly easy.
p.s. My large, burly, testosterone-soaked husband bakes pies at home, too. He tends to use store-bought crusts. Yucko! I’ve gotta work on that boy.