Makesabout 8 cups
                    
                
                
                    
                        
                            - Active time:15 min
 
                        
                            - Start to finish:25 min
 
                        
                    
                
             
            
            
                
                
                
    
      
          
          
          
              
              
              
          
          
          
          
          
              
              
              January 2007
            
          
          
      
  
                
                
            
            
            
                
            
            
            
            
            
                
                    
                    
                    
                        
                            
                            
                            
                                
                                    
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                                            1
                                            lb
                                            purple potatoes such as Purple Majesty or All Blue (see cooks' note, below)
                                            
                                        
 
                                    
                                        - 
                                            About 8
                                            cups
                                            vegetable oil for deep-frying
                                            
                                        
 
                                    
                                
                            
                         
                    
                 
            
            
            
            
            
                
            
            
            
            
                
                    
                    
                    
                        
                            
                                
                                
                                
                                    
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Cut potatoes into very thin (1/16-inch-thick) slices with slicer. Rinse slices in a large bowl, agitating them, then drain in a colander. Spread slices out in 1 layer on a clean kitchen towel and pat very dry. 
                                         
                                    
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Heat 2 inches oil in a wide 7- to 8-quart heavy pot over moderately high heat until thermometer registers 350ºF. Carefully add one third of potatoes, separating slices, and fry, stirring frequently, until chips are crisp, 3 to 5 minutes. Transfer chips with a skimmer to paper towels to drain and season with salt. Fry remaining potatoes in 2 batches. (Return oil to 350ºF between batches.)
                                         
                                    
                                
                             
                        
                    
                    Cooks' note: Purple potatoes are available at specialty foods shops, farmers markets, and from Culinary Specialty Produce (908-789-4700). We prefer Purple Majesty potatoes for this recipe because they result in a crisper chip.