Possibilities really begin to expand when you start steeping grain. I would argue that it’s the most significant change you can make in your brewing. In some ways, it’s no bigger a change than introducing your own hops when you move on from kit brewing. But it’s the point when you have basically all the flavour ingredients you will need; at this point you can start getting the flavour benefits of mashing without needing a 40 litre mash tun. I stuck with extract, steeped grain and hops for more than two years before my first all-grain brew, and some of my best recipes come from that period.
Straining bag. This is a multi-use bit of kit, and you’ll probably end up with two or three different ones by the time you start all-grain brewing. I’ve used mine not just for steeping, but also for the boil, to keep the hops separate from everything else, and for the same purpose while dry-hopping.
Mini mash tun. A small mash can be fun to try once you start steeping; it can add a bit of extra character to a beer, such as using a kilo of Munich Malt for a lager recipe in addition to the light extract. Resources available on the links page show you how to make your own tun if you have some DIY skills, and the same principles apply to the mini tun. You can probably fashion a mini tun out of stuff already in your kitchen and a couple of additional purchases. If you don’t want to spend any money at all, you can probably mash with a straining bag, your 5-litre-plus saucepan, and a fleece blanket for insulation.
Yeast. At this point you may also want to get experimental with yeast. After all, you’re probably experimenting with malt and the hops. Influence on flavour is important if you’re dead set on brewing a specific beer type (Belgian ale, for instance), but it’s just as much fun to just make up a recipe, pick a yeast and go.
It’s important, however, to do your research on the yeast regarding operating temperature and maturing time. A cleaner beer is often produced nearer the lower end of the operating temperature, and some yeasts require much longer in the fermenter to properly mature the beer and produce the flavour you’re after. A case in point is lager; lager yeast run colder and for longer to contribute to the distinctive clean lager bite. The first lager I made with actual lager yeast required me to put the fermenter in a fridge (I happen to have a spare fridge). Some fiddling with a timer plug, plus a bit of cardboard breaking the door seal to let the CO2 out, allowed me to maintain a temperature of 12°C for a week, then 10°C for around six weeks to mature the beer.
Steeping and mashing. Steeping is the soaking of barley and other cereal grains in hot water to release the non-fermentable sugars that give your beer characteristic notes such as “biscuity”, “malty”, “roasted”, “smooth” and others. Almost all brewers will use these additions known as “adjuncts” by some to add depth to the beer. As with hops, look at some recipes to get a feel for how they work in a beer. John Palmer’s excellent ‘How to Brew’ resource goes into detail on the uses of adjuncts and can be found on the links page.
Mashing, on the other hand, is the releasing of fermentable sugars in a temperature-controlled environment. Temperature control is far more important for mashing because it affects the proportion of different sugars and therefore the ABV and flavour of your finished beer. Small-scale mashing is worth trying once you’ve gained some experience steeping grains, as you can get a feel for the process without the large-scale planning – and potential mess – that accompany an all-grain brew. For an introduction to mashing (and more), see John Palmer again.
Boiling. Anything you steep will need to be boiled as malted grain is often covered in lactobacillus, which naturally sours the beer. Lactobacillus is routinely used in Belgian brewing, but if you don’t want that flavour, the wort should be boiled. Once you’re mashing, there’s also dimethyl sulphide (or DMS for short) to contend with. This is a by-product of mashing and has the aroma of creamed corn, but it can be boiled off. Once you factor in the other bugs that could be around, and the fact that you need to boil the hops anyway, there’s really no reason not to boil your wort.