If you're not enthusiastic about yeast, you really need to be.

It's the stuff that makes distillers laugh and cry. Sometimes simultaneously. It's a confusing mix of emotions.

It's fascinating to folks making whiskies (and other spirits) because it really is the proverbial double-edged sword.

Yeeeast! You're Giving Me Mixed Signals!

At its purest whiskymakers get three things to make their whiskies - barley, yeast and water. We all know barley plus water plus yeast gives alcohol (more specifically ethanol, which is not itself enjoyable to drink lest you fashion yourself a sociopath), which is really what whisky is. The tricky part here is that you're aiming to make flavorful alcohol - that is to say, you need to produce stuff beyond ethanol. That flavor comes from congeners, which are impurities that come as a byproduct from the fermentation process. That's right, from a purely chemistry standpoint, these congeners are not the primary goal of fermentation. 

Yet, as I mentioned, you don't want to be downing ethanol. Which is to say you kinda want the impurities that comes with the ethanol production. But not really...

Believe me, we're going somewhere with this. (Image Source: James Kennedy)

See, making whisky is itself an utterly laborious process notwithstanding having to wait at least 3 years before you can even bottle it and call it whisky. And fermentation is itself a fairly tricky and inefficient process. To produce more congener byproducts means you're telling these good folks, you want them to make that process even more inefficient.

It's quite interesting really. These congeners, and more specifically esters, which are responsible for the aromatics, are created by the yeast from ethanol and acid. Yeasts are produce esters as a way to reduce the acidity of its environment. Like oysters producing pearls as a way to isolate itself from impurities, you're going to want to give the yeasts lots of acids and complex ones at that, so they get to producing lots of esters, and interesting ones at that.

Yet the irony is that if the yeast is busy getting distracted on some side quests making those congeners, then they aren't getting down to making alcohol (synonymous with ethanol in this context). And you can't move past the fermentation stage till you get the necessary amount of alcohol (yield) to be put through the distillation process.

These washbacks allow yeasts to do their work - it's about giving yeasts a main goal and a couple of side quests. (Image Source: Whisky Foundation)

So really, you want the fermentation process to get more inefficient so you get to rack up those flavorful congeners, but you also want the fermentation step to be more efficient so you can produce alcohol faster in order to make enough whisky. Seems pretty Sisyphean to me...

Ultimately, like many things in life it's alittle bit of a compromise. You want it to be inefficient to a point and then you kinda need to get things moving. Generally speaking in the fermentation game, efficiency and flavor run in opposite directions.

The Real Reason Why Our Whiskies Are Labelled "Triple Cask" And Not "Schizosaccharomyces"

Is that the case for the most of the industry? Nope, far from it!

Since most big producers need to pump out tons of whiskies annually so we can all have something to drink, they don't have the time to get funky with it and so they've largely converged on a standard strain of yeast known as Saccharomyces cerevisiae, and yes there are a couple of varying strains to it but they're still within the same family.

Why this strain though, you didn't ask, but I'll tell you anyway - it's what the industry has come to conclude (at least for now) is the most efficient, consistent and reasonably flavorful.

Yeasts all look the same, so your local DFS can look well-stocked. (Image Source: iStock)

The reason most whiskies are kinda meh is because they pretty much all the use the same yeast, even with different types of barley (surprise, surprise, most of 'em also use standard varietals of barley for the same reasons), you still end up with the same flavor compounds thereabouts. Which is why cask maturations are such a huge focus for the whisky scene. It's Sherry this, and triple cask that, and that's because casks are an easier and more predictable way to add flavor.

Also it's easier to call an expression "Triple Cask" than "Schizosaccharomyces".

Exciting Times Point (Y)east

As whiskies have had a serious upswing the past several years, new distilleries are popping up everyday worldwide. For these smaller, craft distilleries that have yet make a name, much less whisky for themselves, yeast has been the battleground for which they mount their campaign for recognition (they aren't looking to produce tonnes of whisky every month so inefficiencies are slightly more tolerable). The other two ingredients are relatively more difficult a hill to die on - lest they fashion themselves picking up their shovels and growing new barley varietals or stumbling onto a new gamechanging water source. Some do take up that challenge, of course.

Lallemand Biofuels and Distilled Spirits is one of the world's largest producer of commercial yeast, and where many distilleries source their yeast from. (Image Source: SevenFifty Daily, Lallemand)

But for the most part it's just easier to switch up pouring a beaker of yeast or even better yet, do nothing and let nature do its thing - open the fermentation tanks and let ambient yeasts in, alongside naturally occurring yeast already on the barley. That's known as wild fermentation.

And so for us drinkers, it's a wildly exciting time. The wider challenge to use different yeasts has led to interesting results and a whole spectrum of flavor combinations.

The Big Boys

Now that said, is it wholly the case that these big whiskymakers are going to take it lying down; all these exciting, exquisite yeasty trends? Well, some are, and some aren't.

Some of them, like Nikka, seems to have a few tricks up their sleeves.

This year, they've released a set of whiskies from their two Japanese distilleries (did you know they owned Scotch distillery Ben Nevis too?) - Yoichi and Miyagikyo, focusing on some aromatic yeasts. This is part of their Discovery Series - an annual instalment leading to their 90th Anniversary in 2024, where they look to explore various aspects of their whiskymaking and some behind-the-scenes experiments that makes up their iconic whiskies.

The first series, Volume 1, was focused on peat. You can find that review here.

Deviating from the Scotch approach, Japanese distillers like Nikka use a different set of levers to create the flavors in their whiskies. (Image Source: Cool Hunting)

To be frank, Volume 1 was not particularly exciting for me. Does peat sound remotely as fun as yeast?

Volume 2 got me jumping off my seat. I will happily admit that when I saw the expressions were themed "Aromatic Yeast", I exclaimed "holy crap!" because as I said, it's been a growing frontier, but not one that a major distillery producing tonnes of whisky monthly would ordinarily be particularly fond of. I suppose every once in a while we need our big boys to give us an out of body experience.

It's not that major distilleries don't possess proprietary yeasts strains - a good number of them do, most of them use a combination with the bulk coming from standard yeast strains. What was breathtaking here was that Nikka was about to commit a whole expression to the raging topic at hand. Two expressions, in fact, good lord!

As it turns out Nikka has an extensive reserve of yeast cultures that they've amassed over the decades, "from university strain libraries, from nature, from the mash of various facilities, and from mutation", according to Nikka's chief blender, Tadashi Sakuma. Nikka seems to have accumulated over 700 unique strains, with anywhere from 6 to 10 strains currently employed actively. 

A Cultural Moment In The Making

Here's some cultural context, while big whiskymakers do have to concern themselves a whole lot more about production efficiency and yield (you might also recall that around the mid-2010s period, right at the heigh of Japanese whisky-mania, Suntory and Nikka both had to cut beloved age statement expressions as they ran out of supplies), Japanese distillers don't operate quite like Scotch distillers.

Sakuma, Nikka's Chief Blender. (Image Source: Swan Select)

This is actually highlighted by Sakuma in several interviews,

"For Japan in particular, yeast has provided a way to differentiate its native spirit from that of Scotland, which traditionally considered yeast as a functional, not a flavoring, tool; most Scotch distilleries used the same neutral strain for decades.

Scotch makers found other ways to flavor their whisky—smoking it with peat, for example, and exchanging whiskies among the numerous distilleries in the country to create what would become a culture of blended malts.

In Japan, we do not have this culture of exchange nor the number of distilleries that would make that possible,

Therefore, we have been developing ways to produce various different types of whisky in-house, including the development of our own yeast strains.”

For a good number of decades, the Japanese whisky landscape was pretty much a duopoly, the effect of which has shaped the scene quite dramatically. (Image Source: Visit Hokkaido)

As, I've previously pointed out, Japan's decades long oligopoly in the whiskymaking scene has had far-reaching implications on how whisky is made in Japan. This appears to be at least one manifestation of that dynamic.

And so, this expression is really exciting because it doesn't just touch at a key frontier of the whisky battleground, the first of its sort by a major whiskymaker, it's also a really important cultural moment that emphasises the uniqueness of Japanese whiskies vis-a-vis Scotch. To me, this is a flash point where Nikka proves it's worth its weight, and it's tantamount to them saying "Japanese whiskies are truly unique and worth their hype, and we're going to be the ones to show it to you".

Kudos to the team, regardless of how this tastes (for now), it's nonetheless a very bold and impressive statement. It's the first expression out of Japan in a long while that's truly caught my eye, and I think unfortunately the significance of which seems to go over the heads of most folks beyond the blind hype.

(Re) Discovering Nikka

Scintillating. Will I get back on the Nikka train or will I stay on the platform? (Image Source: Bars and Clubs AU)

As mentioned, I'll admit I haven't been too excited about Nikka for awhile now. I still enjoy their whiskies for sure, their contribution and role in not just Japanese whiskies, but whiskies in total, is incontrovertible. But I just haven't had anything as of late that's really been too invigorating. Perhaps the Discovery Series might be more a story of my rediscovery of Nikka.

Vol. 2 as mentioned (at length), is about the use of yeasts. Nikka mentions that the pair of expressions - a Yoichi and a Miyagikyo, will tap on the whiskymaking giant's reserve of yeast cultures to demonstrate how experimental yeast strains can enhance good aromas and contributes to the original style of the two distilleries. 

Yoichi Aromatic Yeast, Discover Series, 48% ABV - Review

According to Nikka, the Yoichi expression is designed to be reminiscent of ginjyo sake, and is supposedly more floral and fruity.

Ginjyo or ginjo sake is made from rice that is polished to at least 60% of its original size, removing more of the outer parts of the rice grain, and instead leaving more of the white core (known as the shinpaku) which is more starchy and as we've seen above that gives the yeast more to work with, leading to more esters. As such, ginjyo sake generally enjoys a longer fermentation period and produces a lighter more fruity taste.

In this instance, Nikka has only mentioned ginjyo sake, so its worth noting that there's a variant to that sake grade, known as junmai ginjyo, the difference being that with the junmai, brewer's alcohol isn't added, while the ginyo grade itself allows for up to 10% of brewer's alcohol to be added. Subtle differences but since you've read up to this point, what would one more factoid hurt.

Let's get to it!

Color: Light Gold

Aroma: It gave an initial impression of sparkling makgeolli - a Korean rice wine. It had notes of sweet, steamed rice, yogurt, Yakult (a probiotic milk drink popular in Asia), a light sourness but weaved into a milky sweet richness associated with fermented milk. It was almost umami, with a touch of sea spray, and yet a lot brighter than one would expect. Gently, the peat reveals itself, wafting in, smoky but neither sweet nor medicinal. Soft white florals, fresh linen.

There's notes of a maltier base, alittle more akin to honey, and then fruitier - melons, peaches, dragonfruit, papayas. The fruitiness is closer to the scent one would find walking down the fruit section, more aromatic estery and less say, tinned fruits. It ends with a more herbaceous bite - fresh mint and eucalyptus.

Taste: A nice hefty, buttery texture is what stands out first. It's lightly sweet, honey, but also more on the side of cereals - barley grist, oat biscuits, lightly salted. The fruitiness here is more confectionary and ester-y rather than sweet - melons and rambutans strike out most.

There's an interesting mix of earthy, leafy, fruity note that is similar to Greek stuffed vine leaves (it's called Dolmades). The umami, slightly salty, smoky notes reminds me of seared Halloumi or Scamoza. There's a light smokiness to it as well as some red apple peels and bitter dark chocolate.

Finish: The malty, cereal sweetness continues! Oats, honey, quite robust and oily. A little more black pepper here, with a mix of herbaceous menthol, red apple peels, just a tad bit astringent and salty. Finally ends with abit of charcoal ash, peach and parmesan - strange mix but it works.

My Thoughts

This was very enjoyable, exuded a whole lot of complexity and was quite multi-dimensional in its profiles - malty, umami, fruity esters, gentle smoke, creamy, fresh and herbaceous. It tends towards a more savoury, aromatic profile, certainly quite a stretch from your usual Yoichi's.

What was particularly enjoyable was how easy it was to enjoy. I'm always alittle more cautious with these more ferment-y whiskies because they can get quite sour, but here it never got close. The fermented notes were always bolstered by a milky sweetness, or the gentle peat, and accentuated the fruity esters. I also liked the notes of smoked cheese and vinous leaves and earth that the palate gave off, which was aces for me. 

I really appreciated how the flavors were always well balanced. You'd get umami and then smoky, malty and sweet, herbaceous and fruity. The complexity was always well-paired and nicely complemented. If there's one downside it would be the strength. If this was amped up alittle more in oomph, this would be perfect.

Miyagikyo Aromatic Yeast, Discover Series, 47% ABV - Review 

Now, for the Miyagikyo expression, Nikka says that this one's going to offer fruity aromas of stone fruits such as peach and apricot, supposedly enhance Miyagikyo's traditional elegant and fruity style. 

Second one, let's get to it!

Color: Maple Syrup

Aroma: Bright, uplifting scents of stone fruits and orchard fruits - field strawberries, apricots, plums, nectarines, peaches, apples. They're soft, mellow, but perfumery; somewhat fleshy but slightly tart and green. It's a combination of fruit jams and just slightly unripened fruits. It's somewhat confectionary - candy floss, marshmallows, sugar-coated fruit gummies, icing sugar. It's quite floral as well, once you get past the cooked fruit - potpourri, rose water.

Again, there's that cereal maltiness somewhat like Graham crackers. Honey, of course, and a side of fresh mint. Apple juice, as well, with a light touch of minerality. The minerality blends in with a nutty astringency - almonds, walnuts.

Taste: Alot richer than the nose, with more depth. Honey, fruit jams - strawberry, apricots, red apples. There's more baking spices here. Fruit cake, tobacco leaf, milk chocolate, alittle more earthy and buttery here. Cereal notes again, more of barley grist this time. Light peaches, but quite juicy and ripe. A little bit of lacquered wood, with faint, drying tannins.

Finish: Mid-length, washing out quite clean, bright and vibrant. The fruits make a splash here - field strawberries, peaches, blackberries. It's quite similar to Ribena (a popular blackcurrant cordial in Asia). A little more black tea and wood, with a good stash of menthol and eucalyptus.

My Thoughts

This one's pretty straightforward but very enjoyable I must say. It reminds me of the recent Miyagikyo Grande that was a Global Travel Retail exclusive - both very fruity and juicy, except that one was deeper and richer, while this one's brighter and fresher, more vibrant. I can't quite decide which one I like more. I'd say this one edges the Grande out by just an inch.

This expression is a heightened version of the Miyagikyo in terms of how accentuated and flavorful it is - so obviously, if you're already a fan of Miyagikyo, you're gonna enjoy this even more. The fruitiness here is very apparent, no searching needed, really.

However, again if I had to pick a bone with this (which flavorwise, there really is not anything I could say), it's that it could be stronger, with more oomph. 

Sidenote: I'm so sure this would make an incredible highball.

Overall Take

On the whole, I enjoyed the pair quite a bit - they were both simply great tasting and really added to the tapestry of their respective distilleries' repertoire and Japanese whiskies in general. I actually for once can't quite point at any other expression quite like either of them, so big kudos for bringing out something truly new taste wise.

The Yoichi showcased a whole lot of complexity without ever getting difficult to drink, something I appreciate alot. With these fermented notes, you don't know just how easy it is for it to go awry. The Yoichi's performance was stellar. So multi-dimensional, and each set of flavor profiles matched up perfectly. Really thoughtful and enjoyable stuff, that is so unique - the smoked cheese and fruit vines on the palate was just outstanding.

The Miyagikyo was more in the range of what you'd expect, it was a heightened version of the classic Miyagikyo profile, very reminiscent of the recent Miyagikyo Grande expression, except brighter and more vibrant. This was incredibly easy to drink and enjoy. Serve this up to anyone and I guarantee they'll enjoy it.

Between the two, the Yoichi had way more complexity and nuance (masterful stuff, really), while the Miyagikyo was exceptionally accessible and just incredibly easy to love. The only issue I had with both of 'em was that while the notes were so vibrant and all-encompassing, they could both use alittle more oomph and be bottled at a higher proof. If such a variant existed, that's it. It's sealed, this would be the Japanese whiskies of the year.

On the whole, as you can tell, I really enjoyed Vol. 2 of the Discovery Series. This one more than made up for Vol. 1. I'm sold and I'm back on the Nikka train, let's see if they can make it 2-1 with Vol. 3. 

Kanpai!

@111hotpot