Mackmyra Midnattssol (Birch Sap Finish) Swedish whisky

Mackmyra Midnattssol is a limited edition release by Sweden’s Mackmyra distillery. It is aged in ex-sherry and ex-bourbon casks, and casks made from both American and Swedish oak.  It is then finished in casks that previously held birch sap wine. 

What is birch sap wine? Let me explain.

As winter draws closer to spring, deciduous trees that have stored sugar in their roots begin to move sugar upwards in their sap. The maple and birch trees are two trees that produce an edible sap in plentiful supply. As winter warms into spring, these trees begin to produce this sap. People extract that sap from these trees by drilling a hole into the tree’s trunk, and then controlling the flow of the sap (with a tube, a stick etc) into a container. The sap must be collected in early spring before leaves turn green or else, if it is collected later, it will taste bitter. 

Once collected, birch sap is often used as a beverage (it is a traditional beverage in parts of Northern and Eastern Europe). Just as grape juice can be fermented into wine by adding yeast to it, birch sap can likewise be fermented into a wine by adding yeast to a mixture of product that has birch sap as its base ingredient. Birch sap has a low sugar content and it tastes similar to water. So, to make birch sap wine, a winemaker might mix a base of birch sap with sugar, fruit concentrate and lemon juice and then add yeast to this mix. The yeast, at the right temperature, converts the sugars to alcohol, and the product becomes birch sap wine.  

When asked what Mackmyra tried to achieve in choosing to finish Mackmyra whisky in casks that previously held birch sap wine, Angela D’Orazio, the Chief Nose Officer and Master Blender at Mackmyra, says:  

The floweriness of the birch sap wine in the oak in combination of the fruitiness of Mackmyra- which really exceeded our expectations- they really matched well and gave a whole new profile to the whisky, in many peoples opinion, matching perfectly. 

For D’Orazio, the ex-birch sap wine casks add ‘a very flowery, sweet and minerally birch aroma’ to Mackmyra’s distillery character which she says is ‘fresh with citrus and pear in a spicy, herbal surrounding’.  

When asked to provide a glimpse into the way Mackmyra selects or prepares the ex-birch sap wine casks for finishing whisky, D’Orazio explains:  

We infuse our barrels ourselves- so no anonymous old barrels are being used here. The birch sap wine used is a very fine Swedish wine that we order directly from a Swedish winery, Grythyttan Vin, who only does what nature gives in the wild, like birch sap and berry wines. The selection of barrels is therefore done before we use them for the wine. The wine is infused for two months in the barrels, then taken out. The birch sap finished whisky is then lying in the casks for at least 6 months, tested regularly meanwhile.

D’Orazio explains that it is more likely that old casks will present with more problems than newer casks, and while Mackmyra ‘do buy some old casks sometimes’ such purchases are ‘more of a once in a while thing’. This wood policy, which favours newer casks over older casks, is likely to have an important impact on the uniqueness of Mackmyra whisky; particularly in an industry where many distillers simply snap up whatever they can get or boast about using old casks. 

For D’Orazio, a cask which has ‘been lying around for a long time’ is more likely to have defects than a cask which has not. Mackmyra’s wood policy tries to hit the sweet spot, by avoiding casks which are too young or too old. A cask unworthy for aging or finishing Mackmyra whisky, D’Orazio shares, ‘would be a cask with any character that is far out from the others in aromatic profile’ – it may be ‘too young’ (and therefore be ‘short in taste’ with ‘fewer aromatic descriptors’ on offer, or, it may have ‘undesired chemical reactions (malolactic, bad wood, old wood etc)’. 

The use by Mackmyra of Swedish oak also gives the whisky a unique character which can rarely be found in whisky made outside Sweden. D’Orazio explains: 

If any new Swedish oak is being used, it contributes … spiciness in the whisky. More peppery/tobacco/hay notes together with cedar wood/sandal wood/gingery/cardamum notes, dominating a bit over the vanilla tones. 

Malt Mileage Tasting Notes – Mackmyra Midnattssol

Malt Mileage Rating: ★★★★☆

Type: Single malt whisky

Origin: Sweden

ABV: 46.1%

On the nose find honey, rolled oats, lemon, soft menthol, tobacco, and spice (peppercorns, cardamon and cinnamon). 

On the palate the whisky has a curious powdery and granular mouth-feel with notes of saw dust, vanilla, apple, orange peel, orange oil, honey, and very dark chocolate, mild herbal notes of eucalyptus/menthol and spices (especially cardamon). After a while, what was initially cardboard and dried leaves becomes potpourri. Unsurprisingly, there is a sweet sappiness.  

On the finish there is a gust of freshness, with dried apple, pear and hints of lavender with some lemon; but then this freshness fades to the taste of drying wood and potpourri.