In order to craft any Serum, you'll need to interact with a Serum-making Table.

These crafting stations have the shape of a table with many potion bottles and chemistry equipment on it. Their model is consistent throughout the game's areas, so they're easily recognizable. Hovering the mouse over one of them display an interaction icon (hand with pointed finger).

Interacting with a table will open a window, that is composed by four parts:

• The container space at the bottom, where materials for the serum are placed,
  
• The gauge in the middle that regulates the Heat Level,
  
• The large top slot, that will contain the final product once the crafting is completed.
  
• The right panel, which allows opening a Recipe File (if you have it in your Inventory) to be displayed.

To actually create the Serum, you'll need to put the exact amount of ingredients in the material container section, then regulate the Heat at the correct temperature and lastly press "Prepare". That concludes the process.

• You CANNOT make multiple units of a serum at the same time. This means, if you put double the ingredients 'cause you want to make 2 serums at once, this will not work and the recipe will fail. Always make ONE at the time!
  
  
• Some recipes will say "Pure Alcohol" instead of simply "Alcohol". This ingredient is still the same generic "Alcohol" (grey bottle without label).
  
  
• A specific recipe will list as ingredient something like "C3HO3H3": that means Alcohol.

• Ghoul Blood
  Obtained from: looting Ghoul corpses, some Traders, some loot containers
  Appearence: a grey flask.
  Where to find it: all over the world.
  
  
• Scythe Blood
  Obtained from: looting Scythe corpses.
  Appearence: a blue flask.
  Where to find it: in locations with Scythe, look radio messages to know if Scythes spawned somewhere.
  
  
• Mutated Heart (Also called "Mutated Chopped Heart")
  Obtained from: looting Ghoul and Scythe corpses, some Traders, some loot containers
  Appearence: a pink / purple piece of meat.
  Where to find it: all over the world.
  
  
• Mutated Brain
  Obtained from: looting Ghoul and Scythe corpses, some Traders, some loot containers
  Appearence: looks like a pink human brain.
  Where to find it: all over the world.
  
  
• Wolf Gallstone (also called "Wolf Gem")
  Obtained from: looting Wolf corpses, rarely traders
  Appearence: a yellow / orange hexagonal-shaped object
  Where to find it: wolves often spawn at Gas Station after Army Roadblock or in late-game Ashinaka Forest - always check radio messages for eventual Wolf spawns.
  
  
• Scythe Tendons
  Obtained from: looting Scythe corpses
  Appearence: looks like a metal blade without handle
  Where to find it: in locations with Scythe, look radio messages to know if Scythes spawned somewhere.
  
  
• Spitter Liver
  Obtained from: looting Spitter corpses, rarely traders
  Appearence: a dark chunk of meat
  Where to find it: Spitters only spawn in two places: Lake Cheko and Ashinaka Forest. Best place until very late game is Lake. Go around and you will see them (they have yellow firefighter vest).
  
  
• Baba's Hand
  Obtained from: Baba Yagas, rarely loot containers, rarely traders
  Appearence: a blue hand
  Where to find it: Baba Yaga is a rare monster. It spawns only in one place I know of: Cottage, which is in Lake Cheko. There will also be two Baba Yaga near the end of the game.

Tip: The "High Intensity Headlamp" item makes herbs shine when flashlight is pointed towards them, making them much easier to spot.

• Elfdock
  Obtained from: looting it from the ground, loot containers, some traders.
  Appearence: In the inventory: a cylindrical metal box with a plant icon. On the ground: looks like a sunflower.
  Where to find it: all over the world
  
  
• Skullcap
  Obtained from: looting it from the ground, loot containers, some traders.
  Appearence: In the inventory: a cylindrical metal box with a plant icon. On the ground: a dark green bush.
  Where to find it: all over the world
  
  
• Ginseng
  Obtained from: looting it from the ground, loot containers, some traders.
  Appearence: In the inventory: a cylindrical metal box with a plant icon. On the ground: an orange plant.
  Where to find it: all over the world
  
  
• Motherwort
  Obtained from: looting it from the ground, loot containers, some traders.
  Appearence: In the inventory: a cylindrical metal box with a plant icon. On the ground: a green plant.
  Where to find it: all over the world

• Alcohol (Also called "Pure Alcohol" or "CH3OH3O3")
  Obtained from: loot containers, some human enemies, some traders.
  Appearence: a grey bottle without label.
  Where to find it: all over the world.
  
  
• Gasoline
  Obtained from: rarely human enemy corpses, gasoline tanks, traders, loot containers
  Appearence: a dark blue, metallic container
  Where to find it: generally most will be found as static loot in many places, it also can be looted by gasoline tanks which are large cylindrical structures with usually a pipe sticking out of them: interact with the pipe and see if it has gasoline.
  
  
• Spitter Vomit
  Obtained from: looting spitters, rarely traders, rarely loot containers
  Appearence: a bright green flask
  Where to find it: mainly by looting spitters in Lake Cheko or Ashinaka Forest, but sometimes also traders or random loot.

• Pyro's Lung
  Obtained from: looting Pyros mutant
  Appearence: A green-blue-greyish chunk of meat
  Where to find it: Pyros, to my knowledge, spawns only in the Ashinaka Secret Laboratory. Part of an important quest.

• Incomplete Serum, Iteration 288
  Obtained from: looted in Ashinaka Secret Laboratory
  Appearence: A serum injection, but red instead of blue
  Where to find it: as loot in the Ashinaka Secret Lab. Part of an important quest.

• HR-1 Serum
  - Ghoul Blood x2
  - Mutant Heart x2
  - Alcohol x1
  Heat Level: Med-High
  Bonus Effect: Restore 30 Health instantly
  
  
• HR-2 Serum
  - HR-1 Serum x1
  - Mutant Brain x1
  - Skullcap x3
  - Gasoline x2
  Heat Level: Medium
  Bonus Effect: Restore 70 Health instantly
  
  
  HR-3 Serum
  - HR-2 Serum x1
  - Scythe Blood x2
  - Ginseng x3
  - Gasoline x1
  Heat Level: High
  Bonus Effect: Permanently increases Max. Health by +8
  Credits to AntoxaSham for contributing with this recipe.

• SR-1 Serum
  - Mutant Heart x2
  - Elfdock x2
  - Alcohol x2
  Heat Level: Medium
  Bonus Effect: Restore 100 Stamina instantly
  
  
• SR-2 Serum
  - SR-1 Serum x1
  - Mutated Brain x3
  - Motherwort x2
  - Alcohol x2
  Heat Level: Low
  Bonus Effect: Permanently increases stamina by +15
  Credits to Hommedumatch for contributing with this recipe.

• RR-1 Serum
  - Elfdock x3
  - Scythe Blood x2
  - Mutated Brain x2
  - Alcohol x2
  Heat Level: Med-High
  Bonus Effect: Remove 50 Radiation instantly

• CW-1 Serum
  - Scythe Tendons x1
  - Scythe Blood x2
  - Motherwort x2
  - Elfdock x2
  - Alcohol x1
  Heat Level: Low
  Bonus Effect: +15 Max Carry Weight for 12 in-game hours
  
  
• CW-2 Serum
  - CW-1 Serum x1
  - Ginseng x2
  - Wolf Gallstone x2
  - Gasoline x1
  Heat Level: High
  Bonus Effect: +30 Max Carry Weight for 12 in-game hours
  
  
• CW-3 Serum
  - CW2 Serum x1
  - Baba's Hand x1
  - Alcohol x3
  - Skullcap x3
  Heat Level: High
  Bonus Effect: Permanently increases maximum carry weight

• VP-1 Serum
  - Wolf Gallstone x2
  - Ginseng x1
  - Motherwort x2
  - Scythe Blood x1
  - Gasoline x1
  Heat Level: Low
  Bonus Effect: Allows surviving a Visitation Event while in the open, if taken while the event is happening.

• RP-1 Serum
  - Spitter Vomit x2
  - Wolf Gallstone x1
  - Skullcap x3
  - Alcohol x2
  Heat Level: Med-High
  Bonus Effect: Removes 20 "T-Syndrome" amount (Poisoning) instantly

• AS-1 Serum
  - Scythe Tendon x1
  - Mutated Brain x3
  - Elfdock x2
  - Spitter Liver x1
  - Gasoline x2
  Heat Level: High
  Bonus Effect: Temporarily improves "Arm Strength", making melee attacks stronger and reducing weapon recoil.
  
  
• AS-2 Serum
  - AS x1
  - Baba Yaga's Hand x1
  - Skullcap x3
  - Ginseng x4
  - Gasoline x2
  Heat Level: Medium
  Bonus Effect: Permamently improves "Arm Strength" by +0.2
  Credits to AntoxaSham for contributing with this recipe.

• RD-1 Serum
  - Ghoul Blood x4
  - Scythe Blood x2
  - Spitter Vomit x2
  - Ginseng x2
  - Skullcap x3
  - Alcohol x1
  Heat Level: Medium
  Bonus Effect: +10 Damage Reduction for 3 in-game hours.

• REG-1 Serum
  - Spitter Liver x3
  - Ginseng x2
  - Baba's Hand x1
  - Gasoline x2
  Heat Level: Medium
  Bonus Effect: Greatly improves passive health regeneration for some time.

• RS-1 Serum
  - Baba Yaga's Hand x1
  - Elfdock Petals x3
  - Motherwort Leaves x2
  - Wolf's Gallstone x1
  - Alcohol x3
  Heat Level: Low
  Bonus Effect: Improves Stamina regeneration rate.
  Credits to Arbo Ribus for contributing with this recipe.

• PED Serum
  - Scythe's Tendon x1
  - Ghoul's Blood x3
  - Motherwort Leaves x3
  - Alcohol x2
  Heat Level: Medium
  Bonus Effect: Cures erectile dysfunction. This actually has no real effect on the player and can be sold for money.
  Credits to Arbo Ribus for contributing with this recipe.

IMPORTANT NOTE: These serums are part of some quests. Making them before acquiring the recipe in the way intended by the Developer may cause anomalous consequences like breaking the game's story or bugs. Make them before acquiring their recipe at your own risk!

• Boris' Special Serum
  - Incomplete Serum, Iteration 288 x1
  - Pyro's Lung x1
  Heat Level: Low
  Bonus Effect: None: it's a quest item.
  
  
• Life Extension Serum (LE-1 Serum)
  - Ginseng x6
  - Motherwort x4
  - Baba's Hand x2
  - Pyro's Lung x1
  - Scythe Tendon x2
  - Gasoline x3
  Heat Level: Low
  Bonus Effect: None: it's a quest item.
  
  
• Potion of Elation
  - 1x Pyro's Bile
  - 2x Scythe's Blood
  - 2x Ginseng Root
  - 1x Klemens' Teeth
  Heat Level: High
  Bonus Effect: None: it's a quest item.
  Notes: At Kraikretten Cauldron
  Credits to FlashXAron ☕ (Alex) for submitting this recipe