Do I need to whisk the whole time?
Nope. Whisk well at the beginning, then stir every 20 to 30 minutes until the chocolate is fully melted, scraping the sides and corners where chocolate likes to cling. After that, an occasional stir keeps everything smooth.
Can I use chocolate chips instead of chopped chocolate?
Yes, but chopped chocolate melts more smoothly. Chips often contain stabilizers that can make the texture a little less silky. If chips are what you have, use them and whisk a bit extra.
How do I keep it from scorching?
Cook on LOW, stir a few times during the first hour (and scrape the edges), and do not leave it on HIGH for long stretches. If your slow cooker runs hot, switch to WARM as soon as it is melted and silky.
Can I make it dairy-free?
You can. Use unsweetened almond, oat, or soy milk and swap condensed milk for sweetened condensed coconut milk. Use dairy-free chocolate. Brands vary, so the finished cocoa may be slightly thinner. If it feels too thin, let it sit on WARM a bit longer. If it gets too thick, splash in more non-dairy milk.
Can I make it less sweet?
Yes. Use dark chocolate (60 to 70%) and reduce the condensed milk to 10 ounces, then taste at the end. You can always sweeten, but you cannot unsweeten without making more hot chocolate.
What are good mix-ins for a party?
Peppermint extract, a splash of espresso, cinnamon, orange zest, or a little caramel sauce. For adults, a splash of bourbon, peppermint schnapps, or Irish cream works great.
How long can I keep it on WARM?
For the best texture, hold on WARM for up to 2 to 3 hours, stirring occasionally. If it starts reducing and getting too thick, turn it off and stir in a little milk to loosen it back up.