I'll almost always put the samples back. I just make sure to sanitize the hydrometer and such really well; I haven't had any problems yet. I don't take many readings, anyway. One before I pitch the yeast, then one or two to make sure the fermentation is done. Sometimes one on bottling day just to be positive.
A particular love for ancient, obsolete, or lesser-known style from both the US and abroad.
We are the Sons of Winter and Stars
We ́ve come from a far beyond time
Forever the fire burns in our hearts
Our world shall never die