Posted 08 November 2021 by Matt / In Osumi Shuzo
Bottle Name: Essence of Suntory Volume 4 Rice Whisky
Distillery: Osumi Shuzo
Just because something contains natural sugars, this doesn’t mean that throwing some yeast at it will automatically produce a substantive volume of alcohol. Whilst some foods will readily ferment – and indeed others containing microflora and bacteria may spontaneously ferment – no matter the source of the sugar, the creation of alcohol necessitates that an enzymatic conversion process has taken place. Not every food source naturally contains enough of those enzymes for its sugars to become susceptible to this transformation – known as saccharification. But that doesn’t mean that all is lost. Whilst a fair number of categories of spirit (including Scotch malt whisky) prohibit the inclusion of extra enzymes as part of the production process – for others, these adjuncts (additions) are fundamentally necessary. Case in point – Suntory’s Essence of Suntory Volume 4 Rice Whisky – which despite being categorised (more on that later) as rice whisky, also contains a malt component – to achieve proper saccharification and a consistent ferment.
Saccharification, which means “to make into sugar” is the conversion, by enzymes, of starches into sugars and dextrins. It’s why a mash is utilised. And whilst turning cereal into liquid is part and parcel of the process – it is the combination of temperature and moisture which is the primary requirement here. The saccharification process produces the fermentable sugars (and unfermentable dextrins) that create the basis of a wort – the sugary solution which can then fermented out into alcohol. But to be susceptible to digestion by enzymes, starches first much be gelatinised (dissolved in water). Gelatinisation temperatures very depending on the cereal/grain/food (some require a sufficiently higher temperature that they are cooked separately before being added into a mash) – but for malt you’d expect a first sparge water range to be between 61°C and 65°C (142°F and 149°F).
Once the starches have been gelatinised, they are broken down by the enzymes alpha and beta amylase (which are contained naturally within barley) – this produces sugars – in malt – primarily maltose. Alpha amylase is responsible for the hydrolysis of starches into dextrins, whereas the beta amylase digests the dextrins into fermentable sugars. These enzymes also have ideal operating temperatures – which if exceeded will force them to quickly become denatured. The beta amylase will only be active for around 30 minutes at 65°C, whereas the alpha will survive considerably longer. As such, mashing temperatures are a compromise between the higher heat levels required to achieve starch gelatinisation and the lower temps that preserve the activity of the enzymes. There’s much more brewing science here, but we’ll not bore you with that today. Back to the rice…
Rice is as varied as barley. There are many different types – each composed biologically different. But not every rice variety contains sufficient levels of enzymes for it to achieve correct saccharification. As such, when creating rice spirits, external sources of these enzymes are often added. Typically, in Japan this addition would be koji – a cooked rice or soya bean extract that has been inoculated with a fermentation culture (Aspergillus oryzae), which provides the additional source of enzymatic activity. In this manner, all sorts of other ferments can be made: soy sauce, miso, sake and amazake.
But as opposed to utilising the more common koji, Essence of Suntory Volume 4 Rice Whisky uses a malt addition for saccharification and fermentation. The result is the same – a source of converted, fermentable sugars. But the devil of the detail is likely within the categorisation of the produced alcohol.
The newly adopted Japanese whisky standards (which are in many ways more of a guideline, and a less of a rule for the time being) don’t mention rice anywhere. Indeed, at present, fermented and distilled rice products would normally be classified as Shōchū. However, Shōchū, whilst based on rice, can contain many other ingredients - buckwheat, sweet potatoes, chestnuts, sesame seeds - the list goes on. It is also not distilled to above 40% ABV. So where does that leave a product that is fully made from rice and cereal grains, distilled higher than 40% and matured in oak?
The new rules state (among other things) that:
- Malted grains must always be used
- Saccharification, fermentation and distillation must be carried out at a distillery in Japan
Rice can be malted. Similarly, nowhere is the traditional method for rice saccharification (using koji as an adjunct) prohibited. So perhaps, the use of malt for saccharification as part of the process of creating this Essence of Suntory bottling (and indeed, presumably a larger inventory of laid down rice whisky casks) is a calculated guess at a production methods which will likely satisfy some future updates to the developing, embryonic guidelines.
Should koji saccharification be declared verboten in an update, the malted grain stipulation safeguards that this rice-based product could still be made within the rules and notionally could still be classified as a whisky. As with everything Japanese whisky though – there’s a distinct lack of precise clarity here. Time will tell. However, as of writing there’s still plenty of deliberate misclassification of aged Shōchū as whisky. Buyer beware.
Suntory’s maiden rice whisky is not produced at any of its three primary whisky producing sites. Instead, Osumi Sake Brewery (Osumi Shuzo) which commenced operations in June of 2005 and latterly became part of Suntory Group in September 2014 has been used. Osumi’s primary product to date has been a Shōchū produced from sweet potatoes (clarified as “type B” – less than 45% ABV and created from a one-shot distillation). Its utilisation for this rice whisky has produced a special release as part of the producer’s ongoing ‘Essence of Suntory’ series that was released in 2020 alongside a Sakura cask (cherry wood) expression. The release comes in a 50cl bottle and is delivered at 56% ABV. The RRP was 5,500 Yen (£36.30) – but good luck finding it anywhere near that price.
Nose: Underripe peaches and greengages sit alongside vines and reeds, whilst cream-filled choux buns are joined by cask influences from vanilla, sour white oak and pencil shavings. Running throughout – a certain youthfulness from yeasty dough. The addition of water presents a more fruit-forward composition with estery pears and apples joined by crushed digestive biscuits – something of a yet to be cooked orchard crumble.
Taste: More ‘formative’ on the palate with copper pipes, fermenting beer and overt ethyl acetate (pear drop). Nougat, vanilla buttercream, desiccated coconut and savoury brown bread offer considerable creaminess, before flintiness from graphite is joined by chilli and black pepper. Reduction again lifts the distillate. Gooseberry, lychee and white fleshy melon to the fore – spice and prickle to the back.
Finish: Fairly short, and pretty much all cask – cayenne pepper and planed oak.
Suntory’s first foray into rice whisky leaves me feeling inquisitive as to what a longer-aged version could achieve. Whilst there’s undeniable immaturity here, there’s also a great deal of underlying fruitiness (particularly when reduced – which in my view offers far more insight into the spirit than at the bottled 56% ABV) and far less ‘oddness’ than any other rice whisky I’ve sampled to date. In all honesty, tasted blind I doubt I would pinpoint this as rice. But, it’s far from the finished article ‘as is’, and should be viewed more as a pleasantly composed experiment than a clarion call to opening the rice whisky floodgates. Nevertheless, interest certainly piqued.
Thanks to Alistair @SpiritAndWood for the sample
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