My first video demonstration! ;)
Please (try to) ignore the background sounds. Edna was practising on her piano, and Ezra was playing with the pots and pans... *sighs*
This demonstration is on the use of a pastry cutter to rub in cold butter into flour for making shortbread pastry and piecrust pastry. To achieve light and crumbly pastry, cold butter (and cold cold ingredients, especially water) are necessary to prevent the butter from melting.
Here's the video, beginning with a block of butter from the fridge: