I recently bought two different roast levels of Roasted Barley out of curiosity. When I couldn't find any good info on the differences between the two, I realized I was going to have to test them myself.
I had heard of other brewers spiking a base beer with a grain tea made with steeped grains to taste test them, but that always seemed like too much work for lazy ol' me. But then I got thinking - what if I brewed a grain "coffee" instead of tea? A quick temp check of the coffee coming out of my Keurig read 168F - seems perfect, right? The final bit of serendipity was finding a 4-pack of the reusable, fill-your-own type KCup filters at Wally World for 10 bucks. The price was right, and the test was on.
I ran a couple of scoops of the grains through a coffee grinder, packed the filter and brewed as strong a cup of joe as my KCup brewer makes. Less than 2 minutes later I had a cup of Roast Barley coffee ready to add to my base brew. It took a 4:1 ratio of beer to roast barley to get a good taste test, but the end results were pretty good. The diluted beer did taste a bit worty due to the unfermented "coffee", but I really felt like I got a good grasp on the flavors and differences between the two grains using this technique.
I do need to tweak this technique a bit in the future. The grind was pretty fine and led to a lot of grain dust in the coffee. I want to see if I can grind a bit coarser and still get enough extraction. I'm also not sure if this technique will work as well with crystal malts (or base malts/adjuncts for that matter), or if this is something that only works well with roasted malts.