When I posted about making my own cottage cheese, Tess mentioned that I should save the whey for other purposes as it can be used for things like soup stock. Given that whey has attractive nutritional properties, and smells like cheese (and that is always good), I threw the whey from my paneer-making session into the freezer with the idea of making good use of it rather than tossing it down the drain. I didn't have a concrete plan for using it, but considered that I might try substituting it for chicken stock next time I made au gratin potatoes.
Given that cheese is getting more and more expensive, I wanted to add more of a cheese flavor without upping the amount of actual cheese. I also wasn't happy about buying a liter of milk, extracting the curds, and tossing out the rest. However, before I was willing to pour whey all over expensive cheese and potatoes which I took the time to peel and slice, I had to make sure the whey wasn't going to taste funky and almost certainly ruin the dish.
For those of you who didn't look back at the cottage cheese making post, I've re-posted my picture of the collected whey. It doesn't exactly look appetizing, does it? It's not the kind of thing you are just itching to start spooning into your mouth, especially when it's stone cold. Never let it be said that I won't be adventurous in the name of food research. I tasted the whey and "it passed the first test, I didn't go blind" (that line is for the geeky sorts out there who recognize it). It tasted like it smelled, like cheese water. It wasn't something I'd knock back on a hot day, but I couldn't see how it'd spoil my precious potato dish.
The end result was very tasty. I couldn't tell if it was significantly cheesier tasting than usual, but it was certainly good and I'm hoping the protein and blood sugar maintenance benefits of the whey remained intact through the cooking process. I think I used too much whey though as it took 2.5 hours to cook properly. However, I'm not sure that that is necessarily a big drawback. The result was tender potatoes in a creamy cheese sauce. Here's the recipe:
Whey Au Gratin Potatoes
- 4 very large potatoes peeled and sliced
- 2 cups grated cheese (I used a mix of Gouda and cheddar)
- 2 tbsp. all-purpose flour
- **whey extracted from 1 liter of milk (about 3 cups)
- 4 tbsp. cream (or milk if you don't want to make it too rich)
- thyme to taste
- salt & pepper to taste
Place one layer of potatoes in a lightly-greased baking dish. I recommend glass because it's easier to clean. Sprinkle with cheese, thyme and salt and pepper. Repeat for two more layers. I recommend going light on the seasoning, especially the thyme. You don't want to overwhelm the dish.
Whisk the cream with the whey and pour over the potatoes. Bake at 350 degrees F./175 degrees C. uncovered for 2.5 hours until the potatoes are tender and the sauce is thickened.
**While this is what I used, I think it might be better to reduce the amount of whey to 2 cups. This will significantly shorten the baking time as the water won't need to be reduced so much or take so long to heat up and cook the potatoes. Next time, I plan to use less whey.
I would have preferred to make more at once and freeze the remainder, but my baking dish is on the small side (as is my oven). If you want to scale this up, you can just add 1/2 cup of grated cheese (not packed down), 1/2 tbsp. of flour, and a 1/2 cup of whey for every extra large potato you add. I think 6 potatoes and 3 cups of whey might be better than my 4 potatoes and 3 cups.