Similar to poaching these NY-style bagels, poaching the pretzels is a classic step that gives the pretzels a thin, elastic-y crust with a chewy interior and increased browning. When combined with baking soda, this step gives homemade pretzels that classic pretzel flavor while also encouraging their browning and slightly 'cracked' appearance. It's important not to poach the pretzels for longer than suggested, or it can yield a dense crust and less rise within the oven. You can technically skip the step, but the results will be like day and night, particularly when it comes to how browned the baked pretzels are.