Why is my eggshell bobbly? (Pics attached)

[Spaghettio]

I was making carbonara this evening and the first egg I took from the box had a bobbly, lumpy shell. Can any hen owners explain why it might be?

No other eggs in the box were bobbly and it tasted fine. Bought the eggs today from Lidl so they were fresh too.

A few things can cause it - older hens tend to lay thinner eggs which can cause warping. Also heat exposure (less likely in the UK in November, brr!) or poor nutrition (need more calcium carbonate in their diet).

Our hens laid funny eggs during a heatwave once, no issues after that though.

It didn't feel particularly thin when I cracked it. It felt as normal as any other (store bought) egg.

If my grandma was still alive I'd ask her, she kept chickens for 45 years! Her eggs always seemed harder (but I was a child when I baked with them so I could be misremembering).

Not enough grit in their diet or a problem with calcium absorption. It's not uncommon but they'll probably kill the hen when they work out it's laying them.

Oh no! I hope she gets some more grit and survives the chop! 🐓