Brewing with Raw Wheat
Raw wheat is kind of a cool ingredient. You can buy raw wheat products, such as torrified wheat or flaked wheat, but for the money (quite literally) raw wheat is the best thing you can buy.
Before we get into exactly how to use it, let's go over the different wheat products you can buy for brewing and how they're made.
Torrified wheat is a common ingredient in British ales. The raw wheat is placed into a drum and "popped" similar to popcorn. This will give you a neutral, raw wheat flavour that plays well with the "toffee" flavours of many British ales, as well as almost all of the proteins available from the original kernel. It's easy to use because you can mill it with the rest of your grist. It's mostly used for promoting head retention and you probably shouldn't use more than 10% of your grist as the torrifaction process destroys all enzymes and it has no diastatic power. It's often recommended to use a protein rest with it, but as there are no protease enzymes either and you'd have to do your protein rest on at least part of your grist, it's probably best to skip that advice.
Flaked wheat is rolled in addition to being either torrified or micronised. Both processes will destroy any enzymes, and so this shouldn't make up more than 10% of your grist. The advantage of using flaked products are that you don't have to mill them. The drawback is that they soak up an incredible amount of liquid and so you'll lose efficiency.
Wheat malt is simply wheat, rather than barley that has been malted. Wheat is very similar to barley as far as brewing is concerned (certainly more so than rice or corn). Wheat tends to be kilned at a lower temperature than barley and so is generally lighter than even Pilsner malt and it also has more protein and more diastatic power. You will absolutely want to do a protein rest if you are brewing with a significant portion of wheat malt. Keep in mind that protein rests come in different shapes and sizes, so a lower, longer protein rest will give you more ferrulic acid, a precursor to 4-vinyl guiacol (clove flavour) and a shorter, warmer protein rest will give you more materials for acyl production, resulting in esters. Both of these are acceptable when brewing traditional styles using wheat. Wheat malt has been gelatinised, but unlike flaked and torrified wheat, still has enzymes and you can use it up to 100% if you really wanted to.
Raw wheat is the least common and can even be hard to find at your local home brew supply shop because very few home brewers use it. To be frank, it's a pain to mill. You'll want to have an arm of steel or a lot of torque on your drill motor. It's best to do multiple passes, gradually narrowing the gap on your mill until you get the crush you want. There are a couple of things that make this process easier, however; first, there is no husk, so there's no worry of over crushing and 2, it's not friable in the least, so you can spin that motor as fast as you want. Another large difference between raw wheat and all the others is that it has a ridiculous amount of diastatic power. Because it hasn't been heated at all, almost 100% of the original enzymes still exist
If you're using raw wheat, you're going to have to do two things; first, you need to do a protein rest. This will enable protease enzymes to loosen some of the trapped starch particles, which will then be gelatinised during the second step. Your protein rest should be around 122F and your gelatinisation step should be around 138F. 20 minutes for both is sufficient. Once you've gotten that far, the rest of your mash will be equivalent to what you're normally used to (assuming you're used to doing multi step mashes). Raw wheat has a distinct flavour that is very different from malted wheat. It's essential in most Belgian beers vs the toasty, malted wheat flavour found in German hefeweizens, for example.