When two or more people sit down with cups of coffee, conversation almost always springs up. Real life comes to the fore. People actually talk (instead of staring at their phones). Any stuffiness tends to depart quickly. Ceremony is not even considered. Coffee drinkers relax and act normal - if a little excited due to caffeine intake.
The key is that coffee and conversation go together. In our sound-bite-driven society, extended conversations are somewhat rare. Coffee helps combat this. Conversations around java can take place just about anywhere (not just in a house despite my personal preferences). Coffee and talking about real life issues fit together like hand and glove. Therefore, coffee drinking with others provides an excellent setting for either edification or evangelism, depending on who you are talking to.
We as the church should be drinking more coffee. If it helps bring about godly purposes, how and why would we avoid it?