Our first whiskey mash - Milho Rei
The very first whiskey we mashed and distilled was from an heirloom red corn variety.
Our friend Armindo had been growing and breeding this corn in the countryside near Felgueiras (about 40 minutes outside of Porto) to feed to his chickens. He kindly agreed to let us use about 250 kg of this corn in our whiskey-making experiments, if we could replace the corn so that he still had something to feed the chickens!
Modern corn has been intensively engineered to provide more starches - to give more yield, wheras Armindo’s red corn is higher in protein compared to commercial varieties.
Less starch means less sugar, which means less alcohol, which means less whiskey by using this corn. However, more protein, means more flavour! It’s a compromise we are very willing to make.
Compared to working with barley - this corn was also very high in oil. We had a film of corn oil floating on the surface during fermentation. It will be interesting to see how that translates to mouthfeel in the finished product.
A perfect ear of heirloom ‘Milho Rei’ corn.
Not all ears are completely red. Growing outside in a region with lots of corn farmers, the fields of Milho Rei can recieive pollen carried on the wind from other plantations, resulting in a minority of the grains not being red.
The corn being kept dry on the floor in the grain store.
Next year, for planting, the grains are retained from the completely red ears, and used to replant using material which exhibits exactly what we want in terms of appearance and quality.
Sacks of Milho Rei in the distillery, ready for mashing
Our humble wine press, which was used to separate the liquid from the grain before our stripping distillation.
The mash (fermented grains) filled the two large ‘dornas’ in the background. Being in Portugal, wine-making equipment and techniques are always present in our consciousness, and we borrowed from that tradition in the preparation of this whiskey.
Mashing
Mashing and distilling this corn was quite labour intensive. We decided to ferment on the grain (We don’t separate the corn and liquid until after fermentation), and then, like in winemaking, separate using a press, before distillation.
Distilling
We used a classic double pot still distillation to retain as much flavour from the corn as possible (compared with column or triple pot still), where all of the wash was ‘stripped’, in a first distillation before the second distillation where cuts were made and the hearts were saved for barreling.
Barreling
We chose to barrel in new American oak, with a number 3 char, from a local cooperage (20km from the distillery!). A single 100L barrel was produced. Although quite a typical char level, it is also common to use a higher char (number 4) - but the higher amount of carbon on the char layer in the level 4 would remove more of the subtleties of flavour that we achieve using the heirloom corn. We also chose a lower barrel entry proof, to extract less oak character from the barrel, and again, give more space for the flavour of the corn to shine through.