Why does concentrated sugar water look yellowish

On this question of boiling the nectar I would be very interested if anyone has any scientific evidence that this is necessary. From reading forums here and elsewhere it seems some people boil the nectar, some people just boil the water but not with the sugar in it, and some people don't boil anything. I personally boil the water but not with the sugar in it, and i keep the water stored in a plastic container on my counter for a few weeks and use that to make nectar with. I'd hate to think anything i'm doing could harm a bird but if someone thinks so, i'd like to know why. Nectar you prepare contains some bacterial right from the start because bacteria are all over the place, including in the air, so you don't need the bird's tongue to touch it to be "contaminated" it already was. As for bacterial spores, some types need to be boiled more than 2 minutes to kill them, that's why to can food there are particular time schedules. So i'm doubting any boiling is necessary, I just do it because i read you're "supposed to." i'm also doubting the prepared nectars are bad for birds. But again, if anyone has any evidence i'd like to hear it. thanks :-)

Last edited by alexpk321 : Saturday 28th April 2012 at 20:31.