Will having the lid off my fermenting bucket and allowing air in whilst I took readings leave me open to contamination? I'm fermenting in my cellar?
Also, I'm a little concerned that I took my sample with a sanitised turkey baster. Do I need to keep resanitising it every time I dip it into the brew to get a sample? It took about 3 goes to get enough out and it kept dripping. Am worried about contamination!
Actually, I'm probably worried that the end of the baster touched the test jar which wasn't sanitised.
Am I paranoid?!
Yes, very. After a while you'll calm down and learn how to be vigilant about sanitation but not stressed out.
No, you don't need to resanitize the baster every time. It's a good idea to sanitize the top of the hydrometer tube, but the chances that you just infected your batch by touching it with the tip of the baster is very slim.
Think about it this way. You just made some wort, and it's down to a nice temperature, and a few dozen wild yeasts get into your wort from the air. And the wild yeasts are all, "This is AWESOME! Look at all this sugar we get to eat!"
And then A HUNDRED BILLION BEER YEASTS SHOW UP.
"Yeah, hey, how ya doin'? This is a nice bunch of sugary liquid you got here."
And the few dozen wild yeasts are all, "Well...we'd be happy to share it with you guys!"
And then the hundred billion beer yeasts are all, "That's a nice offer. Very generous. But instead of sharing it...we've decided that we are going to take it for ourselves, and you can just go over there in that corner and die quietly."
So once the beer yeasts really take off, it's even harder to infect the beer. There's a layer of CO2 that protects the beer and the alcohol helps protect it from bacteria. Yes, it's still very possible to infect a batch, but with a reasonable amount of caution, you'll be fine.