Worry about oxygen when taking hydrometer readings from carboy?

[turnersd]

Hi, long time lurker, first post.

I'm using Wyeast 3724 Belgian Saison, which notoriously sticks at 1.035 or so. My question is, do I need to worry about how often I open up my carboy and thief out some beer for testing gravity? Do I need to worry about too much oxygen getting in the carboy, especially if fermentation is nearly complete?

Thanks.

 

[beersk]

You probably shouldn't be doing it every day or anything, but once or twice during primary should be fine. Give it a few days in between readings to see if there's any change.

 

[Cyclman]

You have a layer of CO2 protecting the beer, so if you don't go crazy, it'll be fine. Keep the yeast at least as warm at the end of fermentation as it started, and you'll typically be fine. I use a keg bucket and an aquarium heater, works awesome, < $40.