Here’s a group of malts that probably deserve their own category. They are sometimes referred to as “high kilned” malts and in some old text books they’re referred to simply as “darker malts” which can be confusing because they’re not necessarily referring to dark roasted malts like chocolate malt. They’re referring to Munich, Aromatic and Melanoidin malt. These malts differ from pale and lager malt in that they have a higher initial moisture content (resulting in higher modification), they’re germinated at warmer temperatures and they’re kilned differently- warmer sooner and at certain points without ventilation. The goal when making these malts is to produce a rich malt with a strong aroma. Different companies have slightly different schedules but they all have the same objective- to produce melanoidins.
Melanoidins are reddish-brown coloured substances which contribute the characteristic rich bready, malty aroma and flavour. These are also what give bread crust it’s colour and flavour and are produced as a result of Maillard reactions. Maillard reactions occur in all malts to a certain degree (except in air dried “wind” malt). However, in other malts like biscuit for example they occur when the malt is in a dry state. In these “melanoidin” malts it occurs when the malt is still moist. Using the bread analogy again, a breads crust is formed in the oven from the wet dough, as it cooks. The crust has it’s own unique flavour. Whereas, if you toasted a slice of that cooked bread you would get browning but with a different flavour, a toast flavour.
Actually each step in the production of these malts promotes these reactions. Firstly they are steeped until they have a moisture content of 45-48%. During germination the malt is allowed to reach 20-25 C as opposed to 15-18 C for pale and lager malt. These higher temperatures promote the development of proteolytic enzymes, the enzymes which act on protein.The protein in the malt is then degraded during the higher initial kilning at 50C or 122 F into peptides, polypeptides and amino acids. This is done while the grain still contains moisture and is akin to the idea of stewing for crystal malt only at the “protein rest” temperature range to target the action of these enzymes. There is also the formation of sugars occurring during the malting process (aided by the high modification) and when combined with amino acids and heated produce Mellanoidins. This is what’s called the Maillard reaction named after the French chemist who discovered this.
For this batch of Munich I did things a little differently. Firstly I germinated warm, 16 C for the first day just because there was a lot of surface moisture and I wanted that to dry out or be absorbed before bringing it inside. Day 2-5 was done at room temperature. It really took off at day 3 and on day 5 the tray, which was only about 4 inches deep reached 25 C (77 F). What I should have done at this point was spread it out and give it another day at least to let the enzymes develop, but I was impatient and the interior of the grain was easily smooshed between my fingers indicating that it was well modified.
Next 18 hours were at 50 C (122 F) on trays under tin foil in the oven. I figured trays would be better than a big pot for consistency of heat. I noticed with the caramel, the malt closest to the sides of the pot were warmer for quite some time. After 18 hours the moisture content only dropped 10% to 38%.
I then uncovered the barley and put it on screens at 50 C (122 F) for 8 hours. After which the moisture content was at 30%
Temperature was then increased to 60C (140 F) for the next 14 hrs. Moisture content was at 10%
Over the next two hours I increased the temperature from 170 F (77C) to 200 F (93 C)
The next two hours were at 210 F (99 C)
Took my first sample of Munich. I then increased the temperature again to 225 F (107 C) and took a sample every thirty minutes 3 times.
What you may not be able to see in the photos is that the first sample is actually a little lighter than the store bought Munich 10, so it’s probably 7-8L. The second sample is just a bit darker than the Munich 10, call it 12-15L. The third sample is close to the Munich 30-35. The fourth is a deep reddish brown but I don’t have a malt to compare it to. To get a lighter Munich just cure for 1 hour at 210F (99 C) and not 2 hours.
I tasted all of these samples and my samples tasted very similar to the two store bought ones. The dark one was nice and roasty. The Honey malt was quite distinct and I thought I could detect some lacto sourness to it. So I took the pH of each and the Honey was much lower than all of them at 5.12. This makes sense since it most likely went through the couching phase without oxygen at warm temperatures which would promote the growth of lactobacillus bacteria. I’ll have to do some experimenting with this – it’s on the list!
Here’s another recipe taken from Briggs Malts and Malting describing an old method on a two tiered kiln. I have not tried this one yet but I’m guessing that it may be a little less intense as the stewing is done at a lower temperature:
- Steep to 45% with a long warm germination
- 24 hrs at 38C with a slow airstream for limited stewing. Moisture down to 15-25%
- Malt moved to lower floor. Temperature at 75C (167F) for 12 hours
- Cured at 189-212F (87-100C) or even 221F (105C) for 2 hours