I started with 250g sweet rice, after soaking that was 338g. I made 4 small fermentation batches with 75 g each of the soaked rice. Each batch got 150g of additional water as well as 20g of a 25g nuruk/55g water mix. This should give about 245 g samples.
Then I prepared the rice in 4 different ways:
- Steamed - normal preparation, 40 minutes
- Porridge - coarsely ground soaked rice in a food processor, then poured boiling water over it
- Immersion - put rice in the water and brought it to boil in the microwave
- Parboiled - put rice and water in a larger pot of water brought to about 150F, then let it stand for a couple hours. Why parboiled? It's cooked below the starch gelatinization temperature.
Popped it on my balcony which was nice and chilly for the first few days of fermentation, gave it a bit of a swirl twice a day for a week, then let it coast for another week. Unfortunately, a heat wave hit at the end of the fermentation, and things got a little out of hand, and I found pellicles growing, which surprised the heck out of me. I hadn't seen pellicles mentioned in any makgeolli resources before. Pichia and LAB both build pellicles, so perhaps I shouldn't be too surprised. All four batches smelled so off I couldn't bring myself to taste them. But still, something happened and maybe we can still learn something! Results:
Steamed: 157g wonju/69g jjigame/20g lost (jjigame is a little high here because I didn't strain very well on this first batch). Aroma: sunchips, acetone, powdered sugar cookie, fusel alcohols. High pellicle.
Porridge: 172g wonju/48 g jjigame/25g lost. Aroma: acetone, straw, mint, citrus zest, machine shop. No pellicle.
Immersion: 184g wonju/26 g jjigame/35g lost (lost portion a little high because there was a boil over while cooking). Aroma: apple cider vinegar, overripe plum, paste, peppercorn, low buteryic. Low pellicle.
Parboiled: 147g wonju/84g jjigame/14g lost. Aroma: baby diaper, cheerios, cider vinegar. Moderate pellicle.
So, what can we conclude from this? The immersion method seemed to ferment the fastest and most completely with the porridge right behind it. I find it interesting that while the immersion method seemed to free up more starch to be turned into fermentable sugars, but I'm guessing that the porridge got through the sugars faster because there was no pellicle formation at all. The parboiled batch did absolutely nothing at all and smelled by far the worst.
Am I going to change any thing I do because of this little experiment? Well, temperature control is obviously hammered home as an even more important factor, but that's already well known. I have a greater appreciation for stirring the fermentation. I also still want to play around with parboiling rice - seems like it might do something interesting in small portions and very well controlled environment.