Buttermilk instead of milk in white cake recipe
I am thinking about making a Lemon Coconut Cake for Christmas and the recipe I am leaning towards calls for 1 cup of milk. Can I use buttermilk instead? Also, I want to try and up the coconut flavor in the cake I am thinking a little slosh of coconut rum or some cream de cacao. Since the alcohol will burn off I won't be adding too much extra liquid but how big of a slosh could I go, 1/4 cup?
Buttermilk would be a great straight substitute for milk in this cake. Coconut liqueur, however, is mostly water and sugar, so you are going to need to account for that if you add it to your batter.
I would make a syrup with the liquor and baste the cake after it comes out. Why spend time on re-engineering the liquid to solid ratio?
Buttermilk is more acidic than regular milk. Make sure you understand what leavening agents are used and adjust accordingly.
"want to try and up the coconut flavor in the cake I am thinking a little slosh of coconut rum or some cream de cacao."
Creme de caco is a chocolate flavored liquer from cacao thus unlikely to up the coconut flavor.
+1 re: buttermilk. It might change the texture of the cake as it will react with the leaveners moreso than regular milk.
As far as the coconut flavor, been on this bus myself.
I would use coconut milk as was suggested upthread. I would also add coconut extract. Coconut rum isn't going to get you much, flavor-wise and the added liquid and sugar will put everything else off. Likewise creme de coco (aka Coco Lopez). That product is mostly sugar. That said, I have made a recipe that called for it in the batter, but it also had coconut extract, IIRC.
The buttermilk will make the crumb of your cake bigger and you will have a moist cake. Will it be too heavy for the type of cake that you want?
When subbing Buttermilk, decrease the Baking Powder and add/increase Baking Soda.
You will get much more Coconut Flavor from a good Coconut Extract than from the flavored Rum.
Depending on the original Recipe be careful with Coconut Milk it has much more fat than whole Milk.
Or just use a Buttermilk-Coconut Cake recipe: