For Christmas, my brother gifted me with Sandor Katz’s excellent The Art Of Fermentation, and as I’ve been greedily tearing through it, I haven’t been able to help myself from trying some of the more exotic fermentation processes in it.
One that immediately captured my imagination is what he calls “rice beer.” Though, to be fair, the first thing you should do when you hear that term is drop any notion you may have of what comprises a beer. For the purposes of this discussion, a beer is a fermented grain beverage, and Katz presents a simple process, most likely in use in Asian households for centuries or longer, for using rice as the grain.
Basically – Cook rice and let it cool, add an Asian “Yeast Ball” (I acquired them at a local Asian grocery), put it in a crock and allow to ferment. But if it were that easy to turn universally available, extremely inexpensive rice into alcohol, wouldn’t everyone be drinking it?
Photos and my own cut-rate science below…
Let’s start with quantities. Katz says that two pounds of rice will yield about 3 liters of brew, so I felt like that was a manageable quantity, about 4.5 cups, which I cooked in 10 cups of water. The dry rice nicely filled a one quart container.
These are the magical Asian yeast balls (the link explains more about them), but unlike the packets of bread yeast or brewer’s yeast that you buy, these aren’t a monocultured strain of one organism. This is a community of yeasts, molds, and bacteria, because rice, unlike brewing grains like barley, lacks the enzymes necessary to convert starch to sugar. So while a home brewer can steep whole barley and wheat in hot water and drain off sugary wort an hour later, steeping rice that way will produce rice and warm starch water.
So when you crush up a yeast ball and work it into cooled, cooked rice, you’re inoculating the rice with organisms sufficient to create a two-, or most likely, three-stage fermentation. First, the molds – Aspergillus oryzae and Rhizopus oligonsporus, and likely others – come to life and begin their metabolic processes. Aspergillus in particular produces amylase and glucanase enzymes, which brewers will recognize as primary starch converters.
As the mold life cycles liberate sugars from the starches, the second wave of fermentation ramps up and the yeasts bloom, devouring sugars and producing alcohol and CO2. The final product was quite sour, so there’s a third overlapping fermentation from lactic acid bacteria overlaid throughout this.
So the basic procedure is this: Cook rice, let it cool, crush up an Asian yeast ball, work it into your rice, then put it into your preferred fermentation vessel. Here’s mine, a one-gallon glass pickling jar with an airlock. I put it into my bathroom alongside a beer I was finishing at about 80 degrees.
From my notes: “24 Hours – No significant change @ 80 degrees. Took to kitchen and removed lid. Aroma is rich, sweet, earthy, similar to oyster mushroom growing media.”
From my notes: “48 hours, noticed some yellowing [Aspergillus causes yellowing] and one spot of mold visible [which looked very much like this shot of Rhizopus]. Opened vessel and mixed a second yeast ball in. Stirred thoroughly. Strong airlock activity at this time. Aromatics are sweet, strong, boozy.”
From my notes: “72 hours – looks like sourdough starter. The ‘well’ shaped into the center has fully collapsed as liquifaction takes over.”
“85 hours – looks like porridge.”
The shot below is actually of bubbles forming and rushing to the top. By now the mixture has a goopy texture, and the bubbles rarely moved straight up the way they would in a more liquid medium. Instead, they’d form, then shoot away through all the liquid places in the mixture, so you’d see little ghost impressions of bubbles here and there then an eruption at the top.
Okay, so the next Friday, after fermenting for a week, it was time to test this out. Below, my lovely assistant squeezes the rice mash through a grain steeping bag.
We got two quarts of thick, milky liquid. Flavorwise, the closest comparison I can think of is to milk kefir. The flavor after a week at 80 degrees was both alcoholic and strongly soured. My assistant and I took these to a party where a number of people tried the Peasant Rice Brew. I wouldn’t call it a hit, but it was fun to discuss the microbial processes that led to that distinctive soured flavor and share a taste of what one might find traveling in rural Asia.
This isn’t an easy sipping kind of beverage. It’s more of a sour tonic beverage than an alcoholic beer, but it has several advantages – it’s gluten free and it’s dairy free. One food-sensitive friend commented the day after that she could really tell that she’d had some living food and was experiencing less intestinal trouble than she normally would, and I don’t doubt the probiotic nature of this stuff.
The mash left over from the straining was turned into batter the next morning and baked in muffin tins for a really lovely and unique breakfast. Soured rice mash with tart cherry preserves and cocoa nibs – that would have been a hit at the party.
I’m fermenting a five gallon batch of brown rice with a lot more water in it, at ambient temperatures. All in all, this has nearly everything I like – weird food, weird booze, and tons of microbes.