Puff Pastry - cold unsalted butter

Method

• Cut the butter into 3/4-inch cubes. Transfer the cubes to the bowl of a stand mixer. Add the flour and salt to the bowl also and use your hands to mix briefly, until the butter is coated with flour. Put the bowl in the refrigerator to chill for 20 minutes. Combine the water and vinegar in a measuring cup and chill this mixture in the fridge for 20 minutes as well.
• After 20 minutes, use mixer fitted with the paddle attachment. Mix on low speed for 1 minute. You want the butter to break into smaller pieces of varying sizes (the largest about 1/2-inch square);
• slowly add the water/vinegar mixture to the bowl. When the dough begins to come together in large chunks (within about 10 seconds), stop the mixer. Turn the contents of the bowl onto a floured work surface.
• Use your hands to shape the dough into a rough rectangle about 6 x 8 inches and 1 1/2 inches thick. Use a rolling pin to roll the dough into a 14 x 16-inch rectangle. Fold the dough into thirds like a letter. Start with a narrower side facing you and begin by folding the bottom third up. Next, fold the top third down to complete the "turn."
• After you complete the first turn, roll your rolling pin across the top of the dough gently 1 or 2 times. Wrap the dough in plastic and refrigerate for 30 minutes. repeat 2 more times - to create three turns total. Continue to chill the dough for 30 minutes between turns. chill the dough (wrapped in plastic wrap) for at least 1 hour before using.