I've attempted making an Alfredo sauce many times in the past: With flour+butter, without, many different recipes that none have achieved an actual white color. The mushrooms and onion tint the whole sauce in this grey shade which isn't very appetizing. Any tips or tricks for a sauce that's actually white? Thanks.
You don't say how you prepare the sauce, and Alfredo does not contain mushrooms (or flour, or onions). But if you are simply pureeing button mushrooms, then no, there is no way to make it any other color. The mushrooms have black gills, and they will color the whole white sauce.
In theory, you could try removing the gills from button mushrooms before cooking a sauce. In practice, you will probably have enough pieces remaining to give the sauce a light greyish tint.
You can use a different type of mushroom, one without black gills. Porcini should work. Of course, you'll end up with a different taste, and porcini are not a staple in every supermarket. But if you insist on a white sauce, this is the way to go.
Another option is to just eat it as it is. Humans need some time to get accustomed to visual stimuli which are not expected in a given context. But a sauce made with mushrooms, onions and cream is super tasty. After you have eaten it a few times, you can learn to associate it with "good", not "unappetizing". But I guess the success of this method will vary between people.
What I have done to not get the gray colour is:
- Fry your button mushrooms in butter, until soft adding a bit of salt and pepper.
- make a Béchamelsauce with butter (1 Tablespoon),flour (1 Tablespoon) and milk (1 Cup)
- Once your sauce is done, take it off the stove and stir/fold in the mushrooms
Depending on the amount of butter you used for the mushrooms you might get a slight colour change, but it should be minimal. If you really feel like it, you could first pat the mushrooms dry to minimize the colour transfer.
Béchamelsauce has the ability to intensify any ingredient extremely well, but does not keep it's nice saucy look well for very long, so the secret here is make it right before you eat.