Butter is not pure fat; it also contains water and milk solids. That is why an equal weight of liquid oil adds more fat and less water to a recipe. Volume can be misleading: in the reference conversion, the same 200 ml measure weighs 195 and 185 grams, respectively, when filled with butter and olive oil; the two look almost the same.
Replacing solid fat with liquid oil may look like a measurement issue at first, and it is often done gram for gram. But the two ingredients are not the same. Liquid oil is almost entirely fat. Butter is not pure fat: although most of it is fat, it also contains some water and milk solids. That is why an equal weight of liquid oil adds more fat and less water to a recipe; two variables shift at once. So this is not a simple substitution but an adjustment that affects two separate lines of the recipe.
Volume hides this difference and can be misleading. In the reference conversion, one 200 ml measure of butter weighs 195 grams, while the same measure of olive oil or sunflower oil weighs 185 grams. The 2 numbers are so close that someone using volume measures may not notice the difference and may treat those 2 amounts as equal. But what is equal is the weight, not the composition. The proportion of fat in the same measure is noticeably lower for butter, and the recipe reflects that. A volume measure equalizes volume only, not what is inside.
The result shows up in two separate ways in the batter. Extra fat coats the flour’s protein network more thoroughly and makes it harder for the batter to build structure; the cake becomes dense and cookies spread. Less water means less liquid to turn into steam in the oven and contributes less to rising. That is why, when replacing butter with liquid oil, the amount is reduced somewhat and the missing water is added back to the recipe; use milk or water, and adjust the amount by checking the batter’s consistency. Add it gradually and check the batter after each addition.
The change also affects flavor and texture, and measurement cannot make up for that. When butter is creamed, it traps air; most cake and cookie recipes use that air to build structure, and creaming with sugar is done for exactly this reason. Liquid oil does not trap air, so the same creaming step does not help when using it. On the other hand, liquid oil coats flour better and keeps the finished product moist longer; a butter cake firms up as it cools, while an oil cake stays soft. Butter’s own aroma also disappears when it is replaced with liquid oil, and no measurement adjustment can make up for that.
That is why the change is not equally easy in every recipe. In moist cakes, where fat mainly provides moisture and softness, switching to liquid oil is straightforward. In recipes where solid fat provides structure, the change alters the result from the start; liquid oil cannot replace solid fat in laminated doughs or whipped creams. The question to ask is: does the recipe use the fat after melting it, or does it need the fat in its solid state? Recipes that melt the fat are open to the substitution; those that rely on it solid are not.
Comments (5)
Kurabiyede sıvı yağa geçtiğimde hamur hep dağılıyordu, sebebi buymuş. Katı yağın hamurda bir iskelet kurduğunu, sıvı yağın ise yalnız yağladığını bilmiyordum. Aynı tarifi tereyağıyla yapınca şekil tutuyor, sıvı yağla yapınca tepside yayılıyor.
Tereyağının içinde su olmasının hamurda fark yaratması hiç aklıma gelmemişti, gram gram çeviriyordum.
Peki yüz gram tereyağı yerine kaç gram sıvı yağ koymak gerekiyor, net bir sayı var mı?
Kabaca yüz gram tereyağının yağ payı seksen gram; yerine seksen gram sıvı yağ konur ve eksik kalan yirmi gram su ya da süt olarak eklenir. Kurabiye gibi kıvamın yağ yapısına bağlı olduğu tariflerde bu çevrim yine de birebir sonuç vermez.
Keklerde sıvı yağ daha nemli sonuç veriyor bende, kurabiyede ise kesinlikle tereyağı gerekiyor.
Hacim tarafının yanıltması doğru, bir su bardağı tereyağı ile bir su bardağı sıvı yağın ağırlığı hiç aynı değil.