Related Clues:

• Open pastry filled with apple or jam
• Acid or tart
• Acid or caustic
• Pie with fruit filling
• Tasting sharp like stale milk
• Somewhat sour like flat cake
• Open cake with jam etc
• Tasting sour like a lemon
• Sour-tasting pie?
• 'Having a sharp, biting taste (4)'
• Sharp or sour in taste
• Flat pie
• However sweet, you'll not find her an 11 across
• Thus the old city has nothing sweet for us at last
• That's not the sweet part of 26 and 35