Water is a substance we use in our cooking and baking on an almost daily basis. It might be water that we add to our dish or water in which we cook the food. I have written a prior Cooking Tip on different kinds of water. In this Tip, I want to address cooking in water.
In recipes, you will often see different terms when discussing heating water. One recipe might tell you to bring water to a boil, others might tell you to simmer, even others might direct you to do a low simmer. What do these terms mean and do they really make a difference?
According to Wordnik, the boiling point is “The temperature at which the vapor pressure of a liquid is equal to the ambient atmospheric pressure.” At sea level, that temperature is 212°F. Since many of you live at a higher altitude, as I do, you probably already know that that the temperature at which water boils decreases by 1°F for every 500 feet you rise in altitude. That means that where I live (6000 feet), my water boils at about 200°F. I have written before about what effect that has on your cooking, baking and candy making.
As your pot of water reaches that boiling point, the liquid water is converted to water vapor (steam) and this is what you see when looking at a pot of boiling water. Your water does not go from still to a boil in one step. As it heats up, the water goes through different stages.
Many sources use the following terms to describe the stages that water goes through at it comes up to a boil. Note that the temperatures that are listed are for sea level.
- 140 to 170°F
- At this stage, tiny bubbles appear along the bottom and sides of the pan. The surface of the water starts to vibrate or quiver.
- This temperature is good for gently poaching meats, fish & eggs with 160°F being the most recommended temperature.
- Bubbles are now starting to rise to the surface although you will only see occasional tiny streams of bubbles.
- Here is where you want to cook your stocks or very slow-cooking dishes such as a braise or a stew.
- Now bubbles are breaking the surface of the water all over the pot.
- This is the temperature for using below a steamer basket, for use in a double boiler for making delicate dishes or when your recipe tells you to simmer something.
- Some experts just talk about “simmering”, which encompasses both sub-simmer and full simmer. This is a much gentler method of cooking that prevents your delicate food from breaking apart and keeps meats much more tender and moister. For stocks, simmering allows the fats/proteins to float to the top so it can be skimmed off resulting in a much clearer stock.
Full rolling boil
- We all recognize this stage.
- This is where we want our water for blanching veggies, cooking pasta, etc. With vegetables, blanching them in boiling water helps them to cook quickly so they retain their color and flavor. The churning motion of the water keeps the pasta moving so it doesn’t stick and cooks more quickly. If you want to reduce a pot of liquid, this level causes rapid evaporation.
- Using a full boil when it is not indicated can cause the exterior of the food to overcook while the interior dries out.
The Chinese have a different method of categorizing water that uses visual clues and includes the following stages.
- Shrimp eyes – about 160°F
- Crab eyes – 175°F
- Fish eyes – 180°F
- Rope of pearls –200-205°F
- Raging torrent – a rapid boil
When you use water, you want to use cold water. This is not due to the temperature but because hot water contains more dissolved minerals that might result in unpleasant flavors.
What about adding salt to your water? Does it affect the boiling point of the water? Adding salt to water does cause an increase in the boiling point of that water. However, for cooking purposes, this difference is minimal. Harold McGee in On Food and Cooking, points out that it would take an entire ounce of salt to raise the temperature of a quart of water by 1°F. To put this into perspective, he says that this ratio of salt/water is about the same as that of the ocean. Here where I live, I would have to add more than ½ pound of salt to a quart of water to get that same 1 degree increase.
We have all seen recipes that tell you to “bring to a boil and reduce to a simmer”. In fact, one celebrity chef coins this “BTB, RTS”. You might ask why they tell you to take it to a boil if you are only going to reduce it back down. Probably the biggest reason is speed. To get a liquid to boil, we do that over high heat to do so efficiently. From there, it is very easy to reduce to a simmer. To put that same pot over a low-medium heat (a simmer heat) and get to a simmer would take longer.
In conclusion, if you, like my husband, argues that bubbles in your pot means boiling and that there are no differences between these stages, you now have the ammunition to make your point – in a gentle fashion!