Reducing a liquid

[stefanyb]

When following a recipe where there is an instruction to boil down and reduce by half, how do you really know how far you've gone without pouring the liquid out of the pot and into a measuring cup. And how many times do you actually want to do that while preparing something?

If there isn't a time direction, say "cook on a high flame for 5 minutes" or some such thing, I find it very difficult to know how far to boil down.

Is there any rule of thumb about this?

[Jinmyo]

Well, don't stick your thumb in it. But go by eye. Use a pot you know well and that you have a good sense of its volume. Viscosity, the sound it makes, all inform.

[Suzanne F]

And if you do NOT have a good feel/sight of what is half in a particular pot, it's okay to do a little playing with water until you get a sense of it. Measure how much you put in; pour out what you think is about half (back into the measuring cup if you like) and just keep going back and forth until you can consistently come close. Now, of course you won't always start with the same amount of liquid, but this will help you develop a visual sense of what half looks like against the whole amount.

(If you're really worried about getting it right, use a dipstick; but you'll be fine with your own instincts -- especially, as Jinmyo says, because you will SEE and HEAR when it's right.)

[chefette]

Stick the handle of a wooden spoon in at the beginning. You can even mark it if necessary. Then check back when it looks about right. Also, keep in mind that the person who said reduce by half in the first place was just guesstimating probably.

[stefanyb]

Thanks Suzanne, Jinny and chefette. The dipstick method sounds like the thing for me. Maybe over time I can hone my own perceptions but for now, sticking in a wooden spoon handle sounds perfect. I can't believe I never thought of it considering all the car engine repair experience I have .

[Saffy]

This is one of the things that a glass measuring jug in a microwave is useful for. If you are just reducing the liquid to concentrate the flavour a microwave can be helpful in some cases.. other things I would not use this method for .. but it can be handy.

[Nick]

Smell it, look at it, listen to it, and taste it.

[tommy]

nickn and chefette seem have the right idea i think: "by half" means little. it's all about how it tastes. if you go strictly by a measurement, such as a wooden spoon, it's completely random, as it all depends on how much solid material is in the liquid. "by half" generally implies "taste and touch". look at the consistency of the stuff. taste it. spoon it. love it.

[Bux]

nickn and chefette seem have the right idea i think:  "by half" means little.  it's all about how it tastes.  if you go strictly by a measurement, such as a wooden spoon, it's completely random, as it all depends on how much solid material is in the liquid.  "by half" generally implies "taste and touch".  look at the consistency of the stuff.  taste it.  spoon it.  love it.

It pains me to say tommy knows what he's talking about. The least reliable thing is the timing. Heat, composition of the liquid, atmospheric conditions, and other things will affect how long it should boil or simmer. The actual amount of liquid is often far less important than the quality of the final sauce anyway. For the most part this is all done by eye sense of the liquid in the pot, but if the actual amount is critical, I will pour it into a measuring cup once or twice.

[tommy]

It pains me to say tommy knows what he's talking about.

not as much as it pains me to have you agree with me.