Brew kit is simply what you get in the kitchen, but smaller! Some teabags, some coffee, some sugar, some milk, in either powder form or condensed. A few oxo cubes for a beefy warming drink, and maybe a few cupasoups. Try getting some plastic screw lid type containers such as small nalgene containers, less chance of an explosion and coffee covered sleeping bag!
Even if you don't drink tea and or coffee, it's worth taking some. You never know who may visit your site and it is always polite to offer a drink!