My weekend plans have changed... I'm making these fries! I really enjoyed the article. Quite technical, with a bit of plant biology thrown in. When the fries are frozen, it changes the cell structure internally and when deep dried the second time makes the inside fluffy. As the article mentions, freezing causes the moisture inside the potatoes to form sharp and jagged crystals, damaging the internal cell structure of the potato, thereinby releasing moisture when heated up again.