Instruction: Extract information from the supporting document to answer the given question.

Input:
Question: Tea Does anyone know why the inst. say not to brew tea in this kettle?
Document: The "whistling" lid is easy to remove and re-attach.2. Unlike a metal kettle, the glass kettle does not build up metal residue3. Unlike most metal kettles, this product is easy to clean.4. Since it is transparent, I know how much water remains to brew more tea.5. Unlike a coffeemaker, the heating element will not burn out.6.
Bought this as a gift for my mom and she loves it. They use it on a gas stove and sit it directly on the burner. I know they brew tea directly in this but think they said the instructions were against that(?). They haven't had any problems doing that or cleaning it. This was a great product for a great value.
I have been using this whistler kettle brand for over 12 years and Love it! Although the directions say that you should not brew teas in the kettle, I have always done so. I use herbal teas and haven't found that they stain.The kettle does not impart a metallic taste into the water which is a huge plus.The whistle of the kettle is quite loud and you can certainly hear it throughout the house.
I was looking for a basic kettle for the occasional cup of tea, and liked the looks of this. I thought I read enough reviews that it seemed to be a reasonable cheap version and would hold up well. I did not know when I bought this that in order to use it on an electric stove, the heat can not go higher than medium (the instructions say to use low or medium). By following the instructions the first time, it took over an hour to get hot enough to whistle.
This kettle is really nice looking. The reason I'm giving it 4 stars is that the instructions say to only use it on low or medium heat. It takes quite a long time to boil water on medium heat, and boiling water is the whole reason anyone would buy this kettle. Other than that it works well.
I am seriously considering buying a few to keep on hand in case someone (anyone) accidentally drops this and it breaks. OK...so that's the only bad thing I can say about it, it could break if it's dropped.I have an electric stove (hate it but bringing gas to the kitchen and buying a new stove aren't exactly in the budget right now) so I need to use the included metal thingy to raise the class off the electric burner.
Needless to say I felt like a complete goofball... especially since I've worked in customer service for years and know what it's like to receive a return because the customer is an idiot. She just laughed with me and took it back with a smile. Now that I know this, the coil is on the outside and the kettle works perfectly. I wish Amazon would let me change the starts to 5.
I don't think my kettle last for a year. I don't know how my mom made it crack but it broke, something about heat...what ever the glass was made out of it didn't last long, the glass kettle concept was cool but fragile than metal. Even if the product say glass heat resistance or something.Over all the product was okay.but I wouldn't buy it again. It was inconvenient. For my kettle the whistling sound wasn't as sharp and loud as I expected.
Works great! I keep the kettle of tea in the fridge. However, when I am ready to brew more...I run the kettle under warm, then hot water before putting the kettle on the burner again...so as not to crack the cold glass.
I dont even need to use this to know it will be good. German glass? Say no more, already added to my cart. Then to see the reviews. Cant wait and will update when received.
Answer: I'm not an expert or a representative of the company. But I did buy it specifically so that I could steep tea in it. I drink chaga tea, which is a ground mushroom. The grounds stay beneficial through several pots of water and I wanted to be able to see how dark/strong the water was so I would know when to add new chaga grounds. I was very disappointed to see the "DO NOT" instructions, but after talking it over with my scientist husband, I'm using it anyway. We could only posit their concern might be the use of metal or glass infusers, and the problems they could cause by banging or lying against the glass. I'm using a spice bag, with the strings feed through the hole in the lid and tied off on the handle. No problems so far.