If you’re serious about this, I would hire an attorney or talk to state regulators in your state.Absolutely.
As a non expert, two things immediately occur to me. Under federal law (more liberal than some states' laws,) homebrewers legally are permitted to brew 100 gallons per year, for personal consumption only, or 200 gallons in a household with more than one adult of legal drinking age. Thus it is technically illegal to share your homebrew with any guest in your home. This may not be generally policed, but you would be inviting scrutiny, and will be in violation of homebrewing laws if you hold classes in your home and allow students to taste beer. Second, beyond this, if you allow someone to taste beer in connection with a service or event for which you charge money, you will be seen as selling beer without having a license or paying excise tax. That will really get you into trouble.
What laws might apply if you give lessons in the brewer's home I have no idea. But like Tommy said, talk to a lawyer who knows your state's alcoholic beverage regulations.
What makes you believe that you can't share homebrew? Federally, you're allowed to brew beer for "personal or family use".
- Personal use & family use-Beer can be drunk by the brewer and/or their family
- Personal & family use-Beer can be used for personal or non commerical use
I'd lean towards the second option, as a non-commercial use. The law mentions that beer can be removed from the property it was brewed on for "including use at organized affairs, exhibitions or competitions such as homemaker’s contests, tastings or judging. Beer removed under this section may not be sold or offered for sale."(§ 25.206 Removal of beer.) I'm assuming the government knows that not all homebrewers are related to each other, and they simply mean a non-commercial use. This is similar to acceptable personal use of music, software, and other products.
Attorney's are a must for this particular case though. Although I could see you arguing that it'd be no different from a brewery hiring a consultant or contractor to brew a batch of beer. The brewery, not the contractor, would be required to have a license.