No, it is just an adjective, so in the middle of a sentence, you'd just write kosher in lower case.
The word evolution does not need to be capitalized.
No, coral does not need to be capitalized.
No, circa does not need to be capitalized.
No, it doesn't need to be capitalized.
No, kinetic energy doesn't need to be capitalized.
Yes and no. There are many recipes that can be made kosher with kosher substitutes.
Yes! You don't need a kosher cookbook. Just remove the non-kosher ingredients.
No, coral does not need to be capitalized.
The word evolution does not need to be capitalized.
hair color does not need to be kosher.
You need to prepare it and bring it with you to wherever you'll be.
No, it doesn't need to be capitalized.
No, it shouldn't be capitalized.
No, circa does not need to be capitalized.
No, kinetic energy doesn't need to be capitalized.
More and more places are helping religious Jews keep kosher while on vacation. You need to call a Jewish travel agency, request kosher airline food, and stay at a place that keeps kosher.
No. Queries do not need to be capitalized.