Re-boiling water and keep-warm function on electric kettle?
I have read about people not re-boiling water when brewing tea, because it won’t extract the same flavors it would when using freshly boiled water. I have also noticed the changes in flavor when using re-boiled water, so I prefer to use fresh water each time instead.
I want to purchase a kettle that has variable temperature settings, but the one I am wanting to buy requires at least 600ml of water to boil properly at the right temperature. Using anything less than 600ml water will make the water boil regardless of what temperature has been set. This electric kettle does have a keep-warm function. My question is, would using a keep-warm function change the taste of the tea just like it would when re-boiling water? Or does the change in the flavor of the tea only occur when heating the water to a full boil? I would like to know these things before I decide to purchase the kettle I am wanting to purchase. I hope my questions make sense.
I have no problem reboiling. I can’t taste much of a difference if it’s fresh or reboiled, but then again I’m also one of those people who can’t for the life of me understand how some people can tell the difference between Pepsi and Coca-Cola. Heck, I can’t even identify a diet coke although I’ve been told those are supposed to have a characteristic aftertaste. Haven’t spotted that one yet. On Wednesdays when I’m home and Husband is at work, I often fill the kettle up all the way in the morning and reboil it two or three times for making tea in my small one-mug pots.
I haven’t tried the keep warm button on my kettle, but that’s largely because I can’t seem to make it work. I’ve tried using it to keep water warm when making risotto, but it keeps turning itself off. For keeping water warm and ready for tea for a whole day, though, sounds like a waste of electricity to me, so I wouldn’t do it anyway.
Mind you, reboiling like I tend to do is also rather a waste of energy when it’s just because one is too lazy to only boil the amount one needs…
If you use a good quality tea and make 2 steepings, 1 using freshly boiled water and another using re-boiled water, you could probably notice a difference in taste.
There was a recent Cook’s Illustrated where they blind taste tested for this, and their conclusion was most people can’t tell the difference. I’ve been meaning to see if it matters to me really or not—I just took it as handed down from high given, but if I can manage to not worry about it that’d be great as the amount of water it wastes really bums me out sometimes.
I think the difference in taste that comes from reboiling is due to the change in oxygen in the water. When you boil water, you loose the oxygen that is in it. So if you reboil that same water there is already less oxygen to start with. That is why it tastes different. Some sources refer to it as “old” water. There is nothing wrong with it, it just changes the taste minutely in my opinion.
A trick I saw.. errr, I can’t remember what youtube video I was watching, was you can add the oxygen back into the water if you pour it high from the tea pot, say a foot or more higher. I do that trick when I’m letting my kettle keep warm on boiling and dealing with pu’er. I rather not add fresh water over a dozen times for my resteeps.
That sounds like a great trick Awkward Soul. I’m going to try that on the next re-boil in a few minutes :)
I’ve been trying this, and I won’t know if it’s not a mental expectation thing until I do a blind taste test but I could swear it makes a difference! Thanks for the tip.