Carbonic Maceration Grape Ale

We continue to insist on a truth that we believe in: the grape in Portugal and its combination with beer. And as we wrote earlier, we believe in more possibilities than just your usual Grape Ale. For this beer we explore another of these possibilities. For the first time we approached a technique from the wine world. Carbonic maceration of grapes.

Carbonic maceration is a technique used in the production of French wine from the Beaujolais region, namely the Beaujolais nouveau. This wine produced from red grapes of the Gamay variety, is famous for its aroma with fruity notes and light body. And also because it is consumed quite young.

To do this, the grapes are placed in a large pressurizable tank. Then the tank is filled with cO2, purging it of oxygen and creating the gaseous anaerobic environment necessary for the beginning of the maceration. This cO2 will then permeate the grape skin and trigger a fermentation process within the grape berry. As the fermentation proceeds, the grapes expand, breaking the skin. At the same time, the weight of that whole mass of grapes ends up crushing the grapes sitting in the bottom of the tank, releasing juices that also begin to ferment.

Now, we don’t have a farm with huge vineyards, we have a small one only and on top of that, it’s not even that close to where we live. And harvesting is not like it used to be, in the times of our grandparents. Therefore, this experience is recreated at the home brewer scale, with the necessary adaptations and size reduction.


To start, we needed a pressurizable tank. And for that, nothing like a good old soda keg, full of dents. Then the grapes. Cleaned from dust and not much more than that, with the stem still attached. It’s necessary to keep the berry sealed for the fermentation to take place inside, maintaining the integrity until it’s time to burst out. Preparations done, we fill the keg with as many grapes as we can get, but even those will hardly create a high pressure on those at the bottom. Nevertheless, we keep the faith, and we go on with courage. We expect nature, and cO2, to do their job.

Not much going on after one week

But all of this makes our experience take a longer time. At the end of one week you would expect some activity, but after inspection … there was not much going on. That’s what we get for going around watching videos of this technique, which take place in huge wineries, where everything in this maceration happens faster … But at least the grapes remained impeccable in their oxygen-free environment.

We closed it again and continued to supply cO2 to the tank … err keg, I mean. And we wait another 2 weeks. We open the keg again, like a child on christmas day full of expectation while unwrapping a present and hoping to find his intended gift inside. And voilá! White smoke – some, from the cO2 – Habemus fermentation! Broken grapes, grape juice at the bottom, proof of the maceration is taking place. And it smells like a lot like melon! Wait, what !?

After the amazement and adoration, we transferred all of this into a fermenter and pulled a trick out of our hat. Remember that faux-saison from Lithuania that we make in solera format? Well, what better base to serve as a bed for these grapes and to continue fermentation. With the beer already made from the last run of the solera, we transfer it to the same fermenter and the wedding takes place.

Beer? Wine? Juice?

After racking to the fermentor, in the next few days we start a successive task of punch-downs, “remontage” or whatever you want to call the act of pushing the grapes down and breaking the blanket. All done in a 20-liter plastic fermenter, there are no huge stainless-steel conical vats here.

However, life changes. People move. The beer also moves into a cold chamber. The days change, but they all look the same, and months go by before we go back to her again. Until we rescue her from her confinement to continue her journey to the bottle.

Back to it, we transfer the beer to a bottling bucket using a siphon with a metal scrub hack as a filter at the tip, leaving behind the pieces of fruit and skin that create nucleation points on the bottle that do not help us at all … Unless you are looking for a quick way to paint the ceiling. And we can confirm that we are specialists in that. Some bars in Lisbon don’t let us lie.

With a glass in our hands, we remember a past experience – even before all of this took shape – also with grapes. The history and story should not be strange to you. With more than a year to rest, this beer from the past had some problems when she was young and never came into existence. We hoped to have learned from our mistakes. Well, it seems we didn’t learn everything, because we got back on the same track and tried it again. And we will always come back. To the guns, to the guns! About the malt and the grape! To the guns, to the guns! For Grape Ale we fight! With the yeasts we march, march! (This works best if you know the Portuguese anthem…).

Sorry for the reverie. Coming back to reality, while transferring to a bottling bucket, a lot of liquid is lost along the way, but nothing that we weren’t already expecting. Priming done and not forgotten. Beer in the bottles. We complete this voyage to its final destination. Now we let it mature. Like wine. Until the next one (harvesting season).

Carbonic Maceration Grape Ale

Batch: 19L
Total Cereal: 5,03 Kg.
Original Gravity: 1.048
IBU: 30
Boil time: 90 minutes


35% – 1,76 kg. Extra Pale Ale Malt
35% – 1,76 kg. Wheat
15% – 0,75 kg. Spelt
10% – 0,50 kg. Oats
5% – 0,25 kg. Rye


8 gr. Columbus (pellet, ~14% AA) @ 60 min.
35 gr. Vic Secret (pellet, ~15,5% AA) @ 5 min.
20 gr. Saaz (pellet, ~3,75% AA) @ 5 min.


2 Rosemary branches at boil-off. Blessing the kettle.
1 soda keg poorly filled with “Morangueira” grape on carbonic maceration for 3 weeks


Omega OLY-033 Jovaru Lithuanian Farmhouse – Solera
Whatever yeast came with the grapes


Ca: 64
Mg: 7
Na: 36
Cl: 53
SO4: 111
SO4 to Cl Ratio: 2.1


Saccharification – 60 min. @ 66ºC
Mash Out – 10 min @ 76ºC

pH@15 min 5.32


11/10/2020 – Lithuanian solera Saison gets a date with Portuguese carbonic macerated grapes inside a carboy. Looks like there is a bit of chemistry between them.

27/12/2020 – Bottling. Low Yield. This jacked-up filter thing on the siphon always ends with one brewer sticking his arm inside a carboy, to fish out the filter from the remainings of the beer and grapes. Note to self: maybe find a better way to do this.

3 thoughts on “Carbonic Maceration Grape Ale

  1. You have been read. Going down the same path this Fall, with Concord grapes. How did it turn out? From Montreal, Québec.

    1. Great that someone across the pond is reading 🙂
      Turns out that Concord and “Morangueira” are kinda similar ( and both have North-American origin.
      The result was interesting although a bit more “tanic” and less fruity that expected. We’ll post soon our next Tasting & Trials (5) with our review of the Grape Ale.

      This years Grape is already ongoing as well here 🙂

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