title_body: How should I convince my mom that my beer isn't poison?
upvoted_answer: I think the first step in attempting to change a belief of another person is always to understand why they hold that view. That can even help with determining how likely you are to be successful. For example, if her concern is that you may be actively trying to poison her, you're probably not very likely to change her mind. But if instead her concern is just that you may screw up something and produce a contaminated and therefore unsafe drink, that may be easier to handle. But you would use a different argument than if her concern was that you obtained the ingredients from an untrusted source.
  
  To address the latter two options, the simplest way may just be too brew your beer, drink in on several occasions, and then have your continued health be the evidence that it's not poisonous. This has the added benefit of checking it first to make sure it tastes reasonably good (poisonous or not if it doesn't come out well you may want to wait till next time to have her try it).
  
  Attacking it from a more logical perspective, there are a few other arguments you can make:
  
  
  Beer was, for quite some time, a product that was made more because it was safe to drink than because it was tasty. Not being able to trust their water sources, brewing beer was a way to make a drink that was not only less likely to make your sick but also an important source of nutrition.
  From the research I've done, I couldn't find any instance of someone becoming dangerously sick from homebrew. Maybe the occasional upset stomach or bathroom problems but as long as you're being reasonable about cleaning and sanitizing the equipment an infected batch is almost certainly just a matter of it tasting bad, not a matter of your health.
  A big part of the reason for the above points is that the alcohol produced during fermentation should be enough to inhibit the growth of any dangerous microorganisms. That should hold true for even extremely low ABV beers (&lt;1%).
  
  
  Unless you're using dirty, hand-me-down equipment and either aren't cleaning it or aren't properly sanitizing it, you shouldn't​ be able to end up with anything dangerous*. Even then you're more likely to just end up with something you don't like. Long story short, if it tastes and smells good, you'll be fine.
  
  * One caveat here: bottle grenades are a serious issue and can be dangerous. Make sure you clean and sanitize your bottles well and don't bottle until your beer has reached its final gravity. That said, this is more of a physical safety issue than something that makes the beer unsafe to drink.