** a scale. The moisture ratio has to be just right and you won't get that by guessing. Also, you'll need it to portion out your bagels to the same 120g size.
** vital wheat gluten. Even with KA Lancelot HG flour, it's still not right. Get vital wheat gluten and add 1T for each cup of flour (and remove 1T of the flour accordingly for each T of the wheat gluten that you add). This is what makes the dough firm and able to withstand the poaching as well as giving the finished product the distinctive 'chew'. (I believe you can get VWG in Germany if not in CH as I remember looking for it but not finding it.)
** A baking stone. Normally you can work around not having a baking stone but, the end result is so much better with a stone that I'm going to say you really need one for perfect bagels.
** Bagel boards. Don't laugh, yes, bagel boards. All you need is a length of lumber (1x4 is what I use, ironically they are actually 1x3.5"...no idea why) and jute webbing like this ( http://www.onlinefabricstore.net/uph...e-webbing-.htm ). Have the lumber cut to the length of your baking stone so that when you flip the bagels off the boards onto the stone, they stay on the stone. Cut the jute webbing to go over the top and around the front and back sides of the board and just put a few wood screws into the bottom to secure it onto the board. Voila, you've got a bagel board for much less than the $35/board the retail shops charge. I made mine for about $10 total.
** Fine mist spray bottle to prime the oven.
You soak the boards and the stone prior to firing up the oven and, when you put the bagels onto the boards (onto the stone), you spray a bit of water mist onto the stone and the sides of the oven to give it a quick hit of steam. After about 3 minutes baking on the boards, you simply flip them over onto the stone and continue baking until they're done. This also avoids bagels that are flat on the bottom and which have a strange malty crust around the bottom due to sitting in the water they were poached in.
One thing, too, that I note made a big change in the 'shine' factor of the bagels was to wait to put the baking soda into the water bath until the last minute where it will foam vigorously with the malt.
Happy bagel baking.