Since brass is so scarce, I decided to learn to anneal cases so hopefully I will get more life out of them. I watched several videos and proceeded to anneal a batch. I heated them up with a torch pretty good until the necks were glowing pretty well then dropped them in water.After watching more videos I am concerned I might have overheated them. Questions1. Can visual inspection tell if you I overdid it and what signs to look for? 2. What is the downside to over annealing them? Dangerous to shoot? Any advice appreciated.

Over heating the brass can make it very crystalline and burnt,as in oxidized.
Decades ago I would use an old aluminum ice-cube tray and stand my cases up in one inch of water,primers out so they do not try to float and fall over.
I used a propane torch and would heat the neck,shoulder until they just turned color ( think military brass ) and would knock them over with the torch tip.
This worked for many years until I built an automatic case annealer.

Thank you for your reply. Just to understand, if they are burnt and crystallized because of oxidation will they become weak and possibly dangerous if you fire them?

There is a good you tube video out there. Sorry I forget the title. Had to do with over heating and heating too far down. Bench rest guy with all the bells and whistles! He does a lot of videos. I just hold them in my fingers, heat with a propane torch. You won't over heat them!!!! Some people don't use water just let them air cool.

burnt and crystalized means you cooked the zinc out of the alloy.
zinc melts at 787-F and brass anneals at 715-F

if you seen a good green flame in there somewhere you probably cooked the zinc out and changed the brass to not brass or a much lower and softer grade of brass.
[I.O.W copper or close to copper]

Thank you for the info. Looks like I overdid it on the first batch of brass so I will toss them.

So, if the zinc was "cooked out", where did it go, up in smoke ?

You can use Templaq painted on the neck and shoulder, when it melts your done with a perfectly annealed case or so Im told..but folks been using it for ions so it must be good stuff.

Should only heat the neck/shoulder area until it just changes colour. Anneal in a dimly lit room so you can see the colour change more precisely. A very dull red colour change is the top end of temperature and not required. Cherry or bright red is too much and will burn out the zinc as others have pointed out. This is not dangerous if the heat is confined to the neck area but you will loose neck tension and brass strength.

Resizing the cases a few times may work harden and restore some springyness of the case necks although if the zinc is gone it probably won't work. The rest of the case being sized the first time will not be affected by this repeated resizing, only the necks.