Pernik Coal Milk

Notes:

This recipe is our interpretation of "Pernik Coal" ("Пернишки Кюмюр") by Vladislav Todorov and Plamen Kostadinov with some changes, like adding lactose and increasing the percentage of malted oat.

In case the mashing water is too "soft" (like in Sofia, Bulgaria), it's recommended that you add a teaspoon (4-5g) of baking soda for each 20 litres of water to balance the pH level of the mash.

Lactose is added to the boiling wort 10 minutes before the end of the boil. It's not mandatory to add it, the stout would be good enough without it, but it adds some milk sweetness and increases the final gravity, which is desired for this style.

Before adding yeast to the fermenter vessel you should shake the vessel with the wort real well or aerate it in some other way (stirring, using aeration stone, etc.) until you get a nice big foam above the wort. This is to provide enough oxygen for the yeast to replicate well.

Fermentation should take around 10 days (at least two days without activity in the airlock) in the temperature range of 16 - 22 °C. Optionally, you can transfer the beer to another vessel, leaving the yeast bottom behind.

Bottle with 6g of sugar per litre of beer. Before adding it to the fermenter/bottling vessel, you can dissolve it in water, boil it and cool it down to room temperature. This way you sanitize the sugar and make an evenly dissolved solution. Let the beer self-carbonate in the bottles for at least 7 days at room temperature. Then transfer them to a cool place (cellar or fridge) and best let them age for at least a month (better couple of months) so that the flavors can settle.