Whey

Some things to know about whey, a by-product of cheese making: Whey is milk with the fats and solids pulled out (the solids are now in your cheese). It's primarily water but also contains lactose (milk sugar) which is water soluble and ends up draining off with the whey - for the lactose-intolerant, beware.

However, the most valuable ingredient in whey is the whey protein. Milk contains two types of protein - casein and whey proteins. Most of the casein ends up in your cheese and most of the whey protein ends up in the whey, as you would guess based on the name.

In the early days of large-scale cheesemaking, cheesemakers would have to be creative to find uses for their whey. Early on-farm cheesemakers fed it directly back to the animals as a protein source, of course, but once cheesemaking became industrial and moved off the farm, the industry had to find another way to dispose of all that "waste".

Because whey is an excellent source of protein the cheesemaking companies began marketing their leftover product to companies which make protein-enriched products such as protein shakes and bars. Before too long, the protein industry became so huge that it nearly overcame the cheesemaking side of the business.

Sweet Whey

Sweet whey will be exactly that, a whey that has been drained from the curd before the bacteria has had a chance to change a lot of the sweet lactose to lactic acid. Whey drained early in the process, such as in Cheddar, Gouda, Parma, or an Alpine style cheese would be a good example. A normal sweet milk (pH 6.7) made into a cheese such as cheddar may develop a pH 6.3-6.4 before the whey is drained, but other sweet whey can develop acid as low as pH of 5.1-5.2.

This sweet whey can easily be used for making Ricotta. The sweeter whey will produce a richer cheese, but the lower pH whey would give a higher yield.

This can be quite plant friendly as well, if given to plants in your garden, since it includes a lot of nutrients and food value.

However, do not allow this whey to sit very long after draining from the curds, because the bacteria will still be working on the lactose that carries over from the curds, and the whey will eventually become much more acid.

Sweet whey has many commercial uses, mostly because it has more protein and is less acidic than Greek yogurt or acid whey. Because of this, cheese companies can sell sweet whey as a protein supplement or food ingredient. But they can't do that with acid whey. Sweet whey nutritional components proved so profitable that producers began manufacturing cheese just to sell the whey as a food supplement.

Acid Whey

An acid whey will be drawn from a curd that has had a longer time for the bacteria to work, or enough of an acidifier has been added, such as citric acid or vinegar. This will include whey from making ricotta, chevre, sour cream, drained yogurt, etc. Any whey with a pH below 5.1 is classified as an acid whey.

Acid whey can also have a much greater percentage of calcium because as the lactose is converted to lactic acid, calcium is released into the whey and runs off with it. Much of this would normally be bound with the proteins in a cheese that produced a less acid whey.

Acid whey can't be re-used easily. Because of the increased popularity of Drained or Greek Yogurt, the disposal of the acid whey produced has become a serious problem for some communities. The Northeast produced more than 150 million gallons of acid whey last year alone.

Cheese from Sweet Whey

Ricotta

Ricotta cheese, Italian for "recooked," can be made from sweet whey. It is the whey proteins that form this cheese and they would normally be lost if you simply threw the whey away. The sweeter the whey, the richer the flavor of the Ricotta, so do not wait very long to make this after draining the whey. The addition of a bit of cream to the whey will enhance the flavor. See Ricotta Cheese made from Whey

Making Gjetost or Mysost

This is the classic whey cheese from Scandinavia. Gjetost is from goat milk and Mysost is from Cows milk. Essentially the process involves taking fresh sweet whey (preferably from a hard cheese) and then cooking it down over a period of several hours. Cream can be added at the mid-point of cooking and the whole mass requires a lot of stirring. How much cream you add will determine the final consistency as well as how much moisture you remove.

The final cheese will be sweet (from concentrating the lactose), salty (from concentrating the natural milk salts), and either spreadable or sliceable depending on how much moisture you remove in the cooking process. The longer you cook this, the more caramelizing you will taste in the finished cheese. Your end result will probably be about 7-15% of your original whey volume.

The only downside to this use of whey is the amount of energy used to remove the moisture and the amount of stirring that it requires throughout the process.