I have seen several forum posts and articles on how to make everything from amber to chocolate malt but not too much on black malt. The temperatures and times both increase as darkness increases and after chocolate (temperatures over 300F), the process gets difficult to manage. Articles that discuss commercial black malt production mention temperatures between 420F and 450F for 3 to 4 hours. However, this involves drum roaasting with its constant movement to avoid scorching. Attempts to do this at home run into compromises - oven heating can get you the correct air temperature, but no movement; pan heating allows the movement to keep from scorching, but not necessarily the air temperature. Both produce enough smoke that indoors is not a great option. Here is the process I followed to get something close to black malt.
I decided to move this exercise outdoors to eliminate the smoke issue. I did this on my gas grill so that I could get the temperature up to 400F and keep it consistent. To avoid temperature variations and blasts of heat from the gas flames, I placed aluminum foil under the grates all the way across the grill. I also got a proper air probe that can measure temeratures over 400F (most meat probes only go to 200C/392F). Since the lack of movement is still an issue, scorching would still be a concern. I got around that by using parchment paper - I made a small "basket" out of the paper by folding it up on the sides and crunching up the corners to make a paper container. At 400F, the paper becomes brittle after about 90 minutes, so you will need two or three of them. I placed the paper basket into a wire basket so I would have airflow to the bottom of the paper and be able to remove it from the grill easily.
The grain still needs some movement to mix it up to promote even roasting so I would pull the grain out every 20 minutes and shake/stir it. At this time I would also spray it with water (RO or distilled to avoid chlorophenols). This would lower the external temperature slightly so the interior would still heat without scorching the outside. Between the 20 minutes shakes, I would open the lid quickly at 10 minutes and give the grain a quick spray. I set my grill temperature so it would not go over 420F. After opening, the temperature would drop to around 350F, but would quickly bounce back to about 380F, then slowly rise to 420F over the next 10 minutes. My average temperature probably hovered around 400F.
The color of the grain did not change uniformly and seemed to take a while to get dark. Two hours in it was mostly amber with a few brown pieces. Since amber malt is usually made at lower temperatures and shorter time, I think I was being successful in keeping the husks from scorching, but I had concerns it wouold ever finish. After 3.5 hours, most of the grain was black or almost black but few others were still a dark amber. My concern was overcooking the insides of the grain since in previous attempts, the insides essentially boiled out of the husk and turned to charcoal. At this point, I pulled out a cast iron pan and did a 5 minute pan cook with contant stirring (and the spray bottle nearby). To get enough heat in the pan, the gas burners needed to be exposed, so the aluminum was removed as was the drip protector.
Uniformity was still a bit of an issue since inside the grill, I could not manage constant movement to get a consistent black malt. I probably still have about 20% of the malt at a color of about dark amber/brown malt, but I would say what I have is a spectrum of malt between dark amber through brown and chocolate to black malt. I hope to make a porter from this, so a little brown and chocolate malt mixed in is not a bad thing.
I decided to move this exercise outdoors to eliminate the smoke issue. I did this on my gas grill so that I could get the temperature up to 400F and keep it consistent. To avoid temperature variations and blasts of heat from the gas flames, I placed aluminum foil under the grates all the way across the grill. I also got a proper air probe that can measure temeratures over 400F (most meat probes only go to 200C/392F). Since the lack of movement is still an issue, scorching would still be a concern. I got around that by using parchment paper - I made a small "basket" out of the paper by folding it up on the sides and crunching up the corners to make a paper container. At 400F, the paper becomes brittle after about 90 minutes, so you will need two or three of them. I placed the paper basket into a wire basket so I would have airflow to the bottom of the paper and be able to remove it from the grill easily.
The grain still needs some movement to mix it up to promote even roasting so I would pull the grain out every 20 minutes and shake/stir it. At this time I would also spray it with water (RO or distilled to avoid chlorophenols). This would lower the external temperature slightly so the interior would still heat without scorching the outside. Between the 20 minutes shakes, I would open the lid quickly at 10 minutes and give the grain a quick spray. I set my grill temperature so it would not go over 420F. After opening, the temperature would drop to around 350F, but would quickly bounce back to about 380F, then slowly rise to 420F over the next 10 minutes. My average temperature probably hovered around 400F.
The color of the grain did not change uniformly and seemed to take a while to get dark. Two hours in it was mostly amber with a few brown pieces. Since amber malt is usually made at lower temperatures and shorter time, I think I was being successful in keeping the husks from scorching, but I had concerns it wouold ever finish. After 3.5 hours, most of the grain was black or almost black but few others were still a dark amber. My concern was overcooking the insides of the grain since in previous attempts, the insides essentially boiled out of the husk and turned to charcoal. At this point, I pulled out a cast iron pan and did a 5 minute pan cook with contant stirring (and the spray bottle nearby). To get enough heat in the pan, the gas burners needed to be exposed, so the aluminum was removed as was the drip protector.
Uniformity was still a bit of an issue since inside the grill, I could not manage constant movement to get a consistent black malt. I probably still have about 20% of the malt at a color of about dark amber/brown malt, but I would say what I have is a spectrum of malt between dark amber through brown and chocolate to black malt. I hope to make a porter from this, so a little brown and chocolate malt mixed in is not a bad thing.
