Cauliflower rot(?) help.

[nook in the north]

I am growing veg for the first time in Caithness, generally good results but, half the cauli have brown flecks in the head, any ideas why and what it is? Do I have to destroy plants or is it just the result of our fantastic summer?
Appreciate advise.

[Geordie]

This is generally a sign that your caulis are now going past there best, whatever size they have reached.

[PAULW]

Could be slugs where they have eaten bits out of the cauli