I have just discovered flannel bedsheets for the winter and I'm never going back, I can hop under my blankets without shivering. As for the brands, if you're EU-based, check Yumeko.

I use a water boiler (a 1000W one, what a scary number) so I guess there just no way of cutting the cost of my teas any further unless I get a private spring and solar panels :D Thanks for help! :)

I actually finished testing the bottle today. After more than 45h the water was pretty hot, so the bottle is gucci :)

That's a very good advice too, thanks! It's possible that the current ones are compelety messed up, every month I end up with a 3cm thick layer of icy buildup, never had it freezing this bad before tbh.

The water itself is perfect, afaik the best or one the best in Europe but I'm afraid the same cannot be said about the pipes in my rental from the 50's :,)

If I was a camel, I could do that, not drink tea, that is. But I have to drink, sadly, tap water needs to be boiled anyway and buying bottled water would cost muuuch more than boiling what I already have.

Boiling lots of liquid at once would equal boiling smaller quantities more often if not for the energy losses due to the kettle getting warm and stuff. I know it's going to be really marginal and yet, small numbers sum up eventually.

>Up to 45 hours. Not 45 hours guaranteed.

You have a point. I had pretty good experience with Sho bottles which really keep stuff HOT for the promised 12 hours, so I figured that Stanley, a much more respected brand, is SURELY going to deliver 1:1. My bad.

Yeah, I'd say their promised 45h should include some pouring to even be a relevant piece of info about the product; on the other hand, it'd be a bit naïve to expect a company not to brag about the efficiency even if it's achievable only in optimal conditions.

https://physics.stackexchange.com/questions/678761/energy-used-to-boil-a-full-kettle-once-vs-boiling-enough-water-for-a-cup-multipl

Excuse me, I'm not a barbarian, I did my research before I've decided to buy Stanley's portable murder weapon to save electricity by boiling one big pot of water a day :D

Yeah, that's also something I wanted to do: to boil it all at night when it's cheaper and have it ready for the next day.

Well... Can't switch bulbs to LEDs cause I already did it. Can't limit my computer-related electricity usage cause I work from home. Can't unplug devices in standby mode cause I already do this. Landlord doesn't want to upgrade the fridge. If I don't want to freeze, I can't permanently unplug the electric heater in my bathroom either.

The price of electricity is capped but only up to 2900kWh per year for a household, I usually use 3700 so something needs to go if I don't want my gas/electricity bill alone to devour half of my salary.

What I can still do is to switch from heating water in a 1000W kettle 7–10 times a day to heating it once and putting the water in a vacuum bottle to have hot drinks for the whole day ¯_(ツ)_/¯

Sadly I did, so not much can be improved in this aspect. I guess I'll just need to stomach that my XXXL, family-of-6-sized thermos cannot be used the way I wanted to use it 🥲

Yeah, my mistake, was supposed to be 2 days, don't ask me how I went from 45h to 3 days :D Still, 28h is a bit of a bummer but at least I know why it's happening.

Yeah, my mistake and ~2 days would be enough but it doesn't even deliver this, probably because of the reasons stated in other comments.

Half the expected hotness time? I splurge to have the most effective thermos and that's what I get? What a disappointment.

(I'd be more than satisfied with 28–30h of properly hot water though.)

Now I wonder if their "indestructible" model performs better.

The expected temperature retention goes up with the size of the bottle, so I had big plans for this boi.

Thank you for you answer! Yeah, that makes lots of sense. Time for some proper testing without opening the bottle.

If you ever paid as much for gas/electricity as we do now in the Netherlands, you'd understand 😁

But yeah, figured that opening and closing is probably affecting the temperature retention to a certain degree. Didn't know it messes it up that much though.

Anyway, thanks!

Hey, don't look at me, look at their page: "This bottle can hold an entire pot of coffee—or whatever else you may be drinking—keeping it hot or cold for up to 45 hours."

So I assume there must be some circumstances when it's possible.

I wonder if I've missed something then because they claim that the 1,9 l version should keep the contents hot for more than 40 hours 🤔 But as Matthias said below and as I suspected, it's probably the whole deal of opening and closing the bottle.