Tips

Can we substitute products in cooking and baking?

Absolutely!!
I do it all the time and planing to keep adding to this post as I experiment more things ;)
Have you ever been in a situation where you start cooking or baking and you realized you are out of something the recipe calls for or just want to reduce the butter in it? It happens to me all the times.
I've been cooking and baking over 10 years now and I can say I had my proud moments and my failures. The failures made me try even harder to master a recipe as per my taste and desire. The success gave me the determination to experiment more and more.
I am lucky enough to have a husband who eat everything I cook, even if it's not his favorite, and kids who are asking me all the time to make home made version of things they like. And yes, I make many things at home- yogurt, cheese, jams, ice cream, bread, pretzels, buns and so on...

Now back to the topic of substitution in the kitchen  (that what this post is about, right):

• Eggs- approx amount of sparkling drink(soda). Now. if the cake is on egg base and requires 5,6 or more eggs, I wont suggest trying this substitution. The result wont be very pleasant. If you need 1 or 2 eggs, go ahead use soda, no problems at all, or you are short on 1 egg and need 5 or 6 altogether, yes you can substitute it. 
• Butter or oil- same quantity apple sauce (AP) or canned pumpkin (CP). Again, if you are making coffee cake that needs crumbles from the butter, apple sauce wont have same result, but you can use 1/2 butter and 1/2 AS or CP. I assume this will work on shortening also, but I never tried so far.
• All purpose flour- whole wheat flour 3/4 from the required amount and 1/4 all purpose or wheat germ.
• Buttermilk-a)1 cup milk and 1 teaspoon white vinegar or lemon juice.mix well and let stand for 5 mins. Now you can use as much as your recipe needs. b) Pour cream in a clean and dry jar. Close the lid tight and start shaking the jar until the cream turn yellowish and a water separate from the cream 10-15 mins. Use the liquid as a buttermilk and rest as a butter. Make sure to knead the butter under cold water to make sure all buttermilk is removed. The butter now can be refrigerated. c) 3/4 cup of yogurt and 1/4 cup milk. Mix both and use as much as you need.
• Cream for cooking- softened cream cheese. I do this in pasta sauces, soups, or gravies. I use fat free cream cheese instead of the cream just to reduce the calories. Use approx 3/4 of the amount needed mixed with a spoon or 2 of milk (we use 2%) to beat the cheese easier before adding to the cooking meal. Add it at the very end mix well and turn the heat off. The heat from the food in the pan will help the cream cheese melt and spread all over the pan.

• Sugar in sweets - I use sometime sweetener just to reduce the calories. If you are making cake or something sweet, using sweetener may lead to a different taste and be aware sometimes kind of bitter. I suggest you try before making something for friends and family and see how you like it.
• Rum or other alcohol in cakes- use essence with same flavor if you want to keep the flavor as per the recipe. I do this as I serve cakes to kids.
• Coffee in tiramisu for kids- I make small cake for them with cocoa instead coffee and they love it!
• Baking powder- If you are out of baking powder you can use double the amount baking soda and omit the salt in the recipe. It may have slightly different taste, but nothing too bad. IN case you have cream of tartar and baking soda, you can make your own baking powder: 1 part baking soda, 2 parts cream of tarter and use the quantity needed as per the recipe. Exmpl: mix 1 table spoon soda and 2 table spoons cream of tartar (this will make 3 table spoons baking powder). The recipe needs 1 table spoon baking powder. Take 1 tablespoon from the mixed soda and cream of tartar.
• Cram of tartar - This needs different ways of substitution in baking and cooking. If you are using in sweets and the recipes needs only cream of tartar ( in comparing with cream of tartar and baking soda in one recipe) you can replace it with lemon juice. The ratio is 3 times lemon juice to 1 cream of tartar. In baking many times it is combined with baking soda, for this I will update later as I haven't tried it yet and wont recommend anything until I try it myself. I made Turkish delight and replaced 1 teaspoon cream of tartar with 3 teaspoons lemon juice. It was great!