[pollyg]

I was just wondering if anyone could tell me the reason that oil is so often the source of fat in carrot cakes, as opposed to butter.
Does anyone know the science behind it?

[monpetitchoux]

I think most carrot cakes are rather like quickbreads, but sweeter. At room temperature, oil is liquid, so the cake stays softer at room temperature than say a cake made with butter. I think butter cakes (while luscious in taste) are dryer and with a finer crumb than carrot cakes, so maybe oil is prefered because it helps the cake to have a moister mouthfeel. But I really don't know why.

[panini]

method and proceedure. Most of the recipes I use have a type of mayonaise method. Adding eggs slowly to sugar and oil mixture to gain volume and emulsification, just like mayo. Your fat needs to be liquid for this.

[momoreg]

Also, because you have strips of carrot in the cake, butter might tend to make it too fragile, while oil lends a flexibility to the final product.

[nancya]

Oil coats flour proteins well and prevents them from absorbing liquid from the batter to make gluten. Cakes made with oil can be not only tender but very moist, too. When you want a cake or muffins really moist, think of oil. Excellent carrot cakes can be made with oil, such as the Carrot Oil Cake in the 1975 edition of The Joy of Cooking. Oil is also frequently used to make moist, tender muffins. Oil does not have air-holdng ability to aid in leavening, so the eggs and any other thick ingredients like fruit purees in the batter must perform that task.

Shirley Corriher also notes that shortening has an ideal texture for volume and aeration...but butter tastes better in cakes with a soild fat. She says that the fat in the cake is what causes the bubbles that aid in leavening.

[CompassRose]

'Course, carrot cakes make some of the best low/nonfat cakes - because the grated vegetable keeps them nice and moist.

[AlwaysCookin']

The best carrot cake I have ever eaten was made with browned butter. The recipe is in the Jan/Feb 1998 issue of Cooks Illustrated. Please check it out and see if you agree.

I'm back to experienting with cake recipes (again). Time after time my results are best from batters using oil as the fat. I'm totally with Shirley Corriher...the crumb is moister and more delicate with oil vs butter (it has to be due to how the oil absorbs imediately into the flour). These cakes tend to me more flexible and they really do remain "fresher"/"moister" over a longer time frame then other cakes. For a flavored cake like chocolate or carrot etc...you can't detect the flavor of oil over the use of butter. But plain butter cakes do taste best with all butter, but they don't hold as well nor can you acheive as fine of a crumb. I'm going to experiment using part oil in my butter cakes now and see what happens.

You use butter when you need to incorporate air into your batter, paddling it with sugar until it's light (you often need less soda or powder with these cakes for rise). Creaming is a necessary step and gives rise to your cake, otherwise you'd have a dense low baked cake. When you add alot of heavy ingredients into a air lightened batter they will deflate your air pockets. So with a 'heavy' cake like carrot or coconut they use oil instead (they still need moisture) and let leavening come from baking powder and soda instead of air.

[pollyg]

Thanks to all of you for your answers.
I was thinking that the oil had something to do with the carrot specifically, b/c I had not sen any other recipes that used oil, now I think i get it that the oil would be a good shortening for anything heavy that could deflate the creamed butter base. thanks, pol

[marmalady]

I think I read somewhere that carrot cake was one of the cakes developed during the Depression era and also during WWII, (in old cookbooks you'll see 'Victory Cakes'), when supplies like butter and eggs were in short supply. Crafty bakers came up with using oil as a substitute and voila! a tradition was born. I have a recipe for a vegan chocolate cake that came from WWII, that uses no eggs, or dairy and it's pretty darn good!

[pollyg]

They had vegans during WWII? Eating chocolate cake? It's probably just me, but I think that's funny

[marmalady]

There probably were vegans, but I think the recipes came about as a result of food shortages in dairy products; our new-age vegans just glommed onto the recipes. Because they, too, love chocolate!