This one?
Link: http://www.mangago.me/read-manga/the_duchess_50_tea_recipes/
I never read it but perhaps this is it? http://www.mangago.me/read-manga/the_duchess_50_tea_recipes/
The Duchess' 50 Tea Recipes, maybe?
http://www.mangago.me/read-manga/the_duchess_50_tea_recipes/
Its about a modern girl travel back in another world where she became a dukes wife. its a webtoon or manhwa .she can make100 different tastes teas.