How To Boil Water

[Anna Blume]

Planning on cooking pasta for dinner, you turn on the tap, wait until the water gets cold, fill the pot, and bring it to a boil.

How come?

What's the point of starting with cold water each time you boil something?

[catharine]

Planning on cooking pasta for dinner, you turn on the tap, wait until the water gets cold, fill the pot, and bring it to a boil.

How come?

What's the point of starting with cold water each time you boil something?

I heard that hot water comes out of the tap with more minerals, therefore you want to start with more pure, cold water. Is that nonsense? I don't know.

[zoramargolis]

I'd always heard that it was because you shouldn't cook with water that has gone through the hot water heater and its plumbing pipes. That said, I don't always follow rules, and when I am in a hurry, I often start large pots of water that are to be boiled, with hot tap water. I figure, I need the time, and I've already paid for the gas to heat it up partway to boiling. So, a microscopic dose of some undesirable mineral or heavy metal might migrate into the food. Big deal. It's a subvariant of the "eat a peck of dirt in your lifetime" concept.

[dcs]

click

The reason is that hot water dissolves contaminants more quickly than cold water, and many pipes in homes contain lead that can leach into water. And lead can damage the brain and nervous system, especially in young children.

[DanCole42]

The reason is that hot water dissolves contaminants more quickly than cold water, and many pipes in homes contain lead that can leach into water. And lead can damage the brain and nervous system, especially in young children.

Then again, lead is also really, really delicious.

[deangold]

Then again, lead is also really, really delicious.

That explains so so sooooo much!

[jayandstacey]

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I dunno. I hear what they are saying, but the logic is really kind of weak.

So for instance, the quote provided says that hot water dissolves contaminants faster than cold. If I understand correctly, the claim is that there is an amount of lead in the pipes, even "lead free" pipes. OK, so the hot water flows through the pipes and more quickly 'pulls' lead from the pipes -

So wouldn't the logic be this?: The VAST amount of hot water is used for washing and bathing - not consumption. And the hot water only flows through separate pipes for a bit of time (from the heater to the faucet). So wouldn't those pipes become 'cleaner' vs the cold pipes as the impurities like lead are 'pulled' from the pipe walls over many years?

My point is that the same trains of logic they ride in such an article can be said about almost any human activity. A passenger car COULD drive off a bridge into a river. It MAY flip over in a wreck. It CAN burst into a raging inferno. And yes, all of these things have happened, yet do so within a risk tolerance that allows us to climb into those same cars each day. Where are the stats of the number of lead (from pipes) related brain injuries and deaths?

Don't get me wrong, I'm all about saftey regulations where needed. But an article written about trace amounts of lead in hot water vs cold water is, quite simply, a reporter that doesn't have enough to do.

[dcs]

Where are the stats of the number of lead (from pipes) related brain injuries and deaths?

Here is one source:

If the 2003 Canfield et al. nonlinearity findings are correct, then the 14% to 20% of total lead exposure attributable to drinking water may well be responsible for a disproportionately high proportion of the childhood neurological, IQ, and learning deficits caused by lead in the U.S.

The Centers for Disease Control estimates that lead in drinking water contributes between 10%-20% of total lead exposure in young children.

I think the science is pretty clear that almost all of the lead in the water supply is a result of a reaction between the water and the plumbing delivery system, and that hot water is more likely to contain lead in higher quantities than cold water.

For the overall elevated blood lead levels from all sources across the United States look here and here for some CDC statistics.

[jayandstacey]

Thank you for the sources and info. Especially the first source, the link to paper from NIH. It has me thinking, as I sit in my 35 year old house with my two little kids, that I should do lead testing.

Note however, that from a technical (logic / scientific proof) side, I still don't see a proven correlation resulting in risk. Words like "if" and "may well be" show this. The NIH article even says that more research should be done - BUT - it summarizes the known research and concludes, at a minimum, that risk may still exist and is worthy of more attention. Fair enough, and the cost of lead in the water is high enough to be worth the effort, even if the odds of having it in dangerous levels are small.

So.... my takeaways...

1. I should test for lead

2. The design of the test should show me my best strategy of avoiding lead - either using cold water, or simply letting the water run for 1 or 2 minutes before using.

[jayandstacey]

Oh, and PS - my other takeaway related to boiling water is that the biggest thing you can do to reduce lead is to 'clear the pipes' or let the water run for a minute or two before using. This is especially true after the water has been sitting in the pipes for a few hours, such as in the morning. Hot water 'pulls' more lead than cold - but both need to sit against the lead for a while to really absorb a significant amount.