Too much of one spice added to a dish by accident is a problem that all cooks encounter now and then. This is a common mistake when making sauces, such as spaghetti sauce, because a spice's intensity may change throughout the cooking process. If that spice happens to be chilli powder, there are ways to tone down the overwhelming heat. While many of those ways may drastically change the flavour, this method maintains the flavour while cooling it down.
Divide the spaghetti sauce equally into two pan. One batch will be your "experimental group" while the other will be your "control group."
Add 125 ml (1/2 cup) of tomato sauce to the experimental pot of spaghetti sauce, stir and gently heat until it is simmering. Taste the sauce.
Continue adding tomato sauce to the experimental pan until the spaghetti sauce is mild enough for your taste, keeping track of how much you have added.
Add milk or cream to the sauce in 50 ml (1/4 cup) increments if the sauce is still too spicy after using an entire jar of tomato sauce. Keep track of this amount.
Add the same amount of tomato sauce, milk or cream to the control pan. If you've over-corrected the experimental pan and made it too bland, simply add small increments of the control group and mix, tasting as you go, until the spice is right.
Combine the two pans and bring to a gentle simmer.
Taste to ensure the correct seasoning. Add more tomato sauce or milk as necessary to balance out the flavours.
This method works because the acid in the tomatoes and the fat in the dairy counteract the heat of the chilli powder. Experiment with other types of acid and fat to see if you can achieve the same effect, such as vinegar or butter.
Many people will tell you that adding sugar to your sauce will mitigate the heat. This is true; however, adding enough sugar to counteract the spice may adversely affect the flavour of your sauce, making it too sweet.