Left to their own devices, many seedless grapes would be puny and soft. But these Thompson seedless got pleasingly plump after a little girdling and hormone treatment. Daniel M.N. Turner/NPR hide caption itoggle caption Daniel M.N. Turner/NPR The Salt We Like 'Em Big And Juicy: How Our Table Grapes Got So Fat March 8, 2013 Girdles and hormone therapy for grapes? California farmers go to great lengths to plump and firm up grapes as much as possible. But don't worry: None of these techniques hurts the grapes or those who love them.