Cheese is basically made up of protein and fat. If I take non-fat milk and add more protein (i.e, from protein powder), and more fat (i.e, olive oil, or some other type of oil), will it produce more curds when I make homemade cheese? Does it also depend on the type of protein I use and the type of fat? Or does the amount of curds produced depend on something else?
I know this sounds like an unusual question, but I have my own reasons for asking. =)
Yes, you will get more curds. Producers in markets with low legal requirements on labeling and high price sensitivity (e.g. Eastern Europe about 10 years ago) used to do this a lot for feta-type cheese. They still do it, but nowadays they are required to label the cheeses containing vegetable fats, so their more expensive competitors producing standard cheese have part of the market too.
When you use vegetable fat, you get more curds, and a very cheese-like taste, at least if you do it properly. (I suspect that the producers emulsifiy the fat first, but have no detailed knowledge of their process). Under some legislations, you cannot call the product cheese, but this will vary regionally, and probably won't matter to your kitchen.
As for the proteins, you probably want them to be in a curdable state before you add them. If you add proteins which have already been curdled and then pulverized, they will just get in the way of the existing ones and create a cheese with a bad texture. I think that the typical whey protein isolate you can buy in a sports store is already curdled, but my experience with it isn't very extensive, maybe there are curdled and raw products on the market. What you can use is to e.g. add fresh soy milk, in which case you will be making a hybrid of cheese and tofu. You could use milk proteins, which will give you a good cheese, but I am not sure where you can find pure milk proteins as opposed to normal powdered milk which still contains the fat and carbs of the original.
As for the taste and texture, they will be far from normal cheese. Without the benefit of a research lab and food technologists working for you, you are unlikely to create a good imitate tastewise. Even the commercially produced vegetable-fat-feta has some difference from pure-milk-feta if one knows what to look for, and its melting behavior is totally different from normal feta (it practically dissolves). So, I don't know why you are trying to do it, but while you certainly can produce some kind of edible result, don't expect to get a perfect cheese imitate.
I am not sure what "more curds" means, or how to answer that.
You can enhance the firmness of fermented/curdled dairy products by adding milk proteins (such as non-fat dried milk), because there will be more protein to interlock and form the gel that is characteristic of yogurt, creme fraiche, sour cream and so on.
The fat does not directly participate in curd formation, but is interlocked within the complex colloid that is formed during the fermentation or acidification from the casein.
Milk fat has unique characteristics which will not be matched by another fat, most importantly:
Furthermore, it is emulsified into the continuous liquid phase and so evenly distributed throughout the resultant cheese or curds or yogurt or whatever you are making.
While not impossible, you would have difficulty integrating another fat into the liquid phase in a smooth, emulsified manner.
I'm interested in this as well. I've made paneer with full-fat milk (actually augmented with cream to get the fat fraction up to 4% to approximate that in buffalo milk). Recently I've been interested in making a full-fat paneer with healthier fats: low erucic acid mustard seed and coconut oil. Here's what I tried:
I computed the fat fraction of 3.25% milk at about 5-3/4 fluid ounces, and mixed equal parts of my two fats. I then took a tablespoon of lecithin granules as an emulsifier, added a couple of of tablespoons of water and mixed to produce a slurry, with a bit of heating to encourage solution (lecithin is only mildly soluble in water). I added my oil to this drop-wise, with stirring, achieving what appeared to be a smooth emulsion. I then added my skim milk, drop-wise at first, and then at a slow flow, while whisking, to a total quantity of about a pint: a bit more milk than oil. To completely mix the emulsion, I used a blender. The result was pretty good: a completely homogeneous mix. I added this to the remainder of a gallon of skim milk, and proceeded to make paneer as usual.
I got less curd than expected, but am not sure if it was more than a straight skim paneer. It was a bit crumbly, suggesting low-fat, but still had a full-fat mouthfeel to it. It pan fries just like regular paneer, with no exuding of fat. I got about 400 grams worth. I don't know how much of the perceived change is because of the added fat though.
