Nama-zake, or unpasteurized sake, is something I come back to often in this newsletter series. There are a number for reasons for that, mostly surrounding its technical complexity and dubious nature in the flavor and aroma department. While there are many articles on this to be found in the archives of this newsletter, let’s sum it all up with a few lines.

Most sake is pasteurized twice, once after brewing and once again after maturation and before bottling. This stabilizes the flavors and aromas by killing off some bacteria, and deactivating enzymes that would feed them. Unpasteurized sake, nama-zake, should - dare I say must? - be kept refrigerated to keep it from getting weird on you. Remember too that there are degrees of this weirdness, some intolerable and others simply idiosyncratic or even quirkily appealing.

Next, note that sake matures entirely differently and at different speeds before and after pasteurization. And the method used too is of tantamount importance. Whether it is done once or twice, to what temperature it is heated, how long it stays there, how fast it is cooled down, and many other factors will hugely affect everything about a sake. Polarizing for simplicity, too powerful a pasteurization will give you great stability but strip the sake of character. Too light a process will leave it lively but unstable as well. Add to that the timing of all this - and the style of sake at which the brewer is aiming -  and you’ve got yourself a complicated situation. Welcome to the art of sake brewing. But I digress.

Nama-zake can be appealing to many but not a few professionals find that the characteristic aromas et al of an unpasteurized sake obscure its depth and true nature. So while many try to market nama as better than pasteurized sake, it is not unequivocally so.

And, of course, none of this is cut and dried, black and white, here or there. Nama-zake can be great if properly handled and stored and not too mature.

So, with all that as a backdrop, let us consider some recent trends in the area of pasteurization. In short, more and more brewers are trying to get away with as little pasteurization as possible, or more correctly worded, tweaking the process more and more to maintain as much lively freshness, subtlety, and depth as they can yet inject enough stability for the market.

Naturally, many brewers don’t mess with this kind of thing as their sake styles would not benefit from it. But I seem to notice more and more brewers pasteurizing but once and using refrigeration more, or bending over backward to cool down the sake fast, or minimize the applied temperatures, and other house secrets here and there. Surely it is a good thing as they are pursuing both quality and appeal. But it has its inherent risks.

Consider the plight of a large and very reputable brewer from a very prestigious region. A few weeks ago they released a singly-pasteurized version of one of their products. It was released as a hiya-oroshi, which basically means it was pasteurized only one time and shipped a tad young. Normally this should be pretty stable, not absolutely needing refrigeration although likely better off with it, a bit young and lively as well.

But something went amiss somewhere. More of the havoc-wreaking “hi-ochi kin” lactic bacteria were present than thought, or the temperatures used were not high enough, or something else. It is hard to know now, but after shipping thousands of bottles, a bunch of them here and there went way, way south. As such, the brewery was forced to recall the whole lot, even if most of them were fine.

That hurt. It hurt the brewery and it hurt the distributors and the retailers that had pre-sold the stuff too. The image of that brewery surely took a chink in the ole’ armor in the eyes of consumers too. (They’re solid, though, rock-solid; they will be fine for sure.)

In their pursuit of something special, in their drive for using cutting edge methods to create even more appealing sake, they pushed the envelope. And nature won that inning. She always does bat last.

More than the quandary of this one particular brewery, the main point here is to show how tricky nama can be, the complexity surrounding it, and how one seeming trend is to challenge and take some risk that can reap rewards - or backfire.