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Equipment: Rotovap

Info

  • The main aim of distillation is to create a process of evaporation and condensation

Basics
  • Distillation start with a fermented alcoholic liquid
  • The liquid is heated and brought to the boil
  • In order to separate the alcohol from the rest of the liquid a distiller can take advantage of the fact that pure ethanol (the most common alcoholic beverages) boils at a lower temperature than pure water
  • As a result, when an alcoholic liquid boils, the vapours that are created contain a higher proportion of alcohol than the boiling liquid
  • The vapours created by boiling the alcoholic liquid are collected and condensed back to a liquid that has a higher alcoholic strength than the original liquid
Pot Stills
  • Also known as “Alembic stills” Image
  • Consists of a large kettle or pot which is heated from the bottom, boiling off the alcohol and allowing the vapors to be sent to a condenser and separated
  • Pot stills operate on a “batch by batch” basis
  • Typically made entirely from copper-(good conductor of heat and extracts sulphur from the distillate)
  • Used to produce a more flavoured distillates such as single malt scotch,mezcal, rum or cognac, but not rectified spirits, because they are bad at separating congeners
  • They are made in different shapes and sizes depending on the quantity and style of spirit
  • Can produce spirit between 60 and 80% ABV, after multiple distillations
  • Components: Kettle/Heat Source ( bottom part where the ferment is heated), ferment is evaporated and the vapours travels through Swan-shaped Neck, reaches the Condenser(spiral-shaped copper tube) where the vapour is condensed to a liquid - Spirit
Column Stills
  • Also known as Coffey/Continuous/Patent stills Image
  • With column distillation, the mash enters near the top of the still and begins flowing downward. This brings it closer to the heating source, and once it’s heated enough to evaporate, the vapour rises up through a series of partitions known as plates or stripping plates. At each plate along the way, the vapour ends up leaving behind some of its heavier compounds and congeners.
  • Column stills may be operated continuously
  • Can produce spirit over 95% ABV
  • Made from stainless steel, copper, or mix of the two
  • Used to derive white or neutral spirits like vodka, gin or white rum
  • The more floors a column still has, the more rectified the final distillate will be Image
Process
  • Items distilled in the Rotovap need careful consideration, especially when using allergen containing ingredients.
  • Ensure that cross contamination does not occur by creating a safe space to work when filling the evaporation flask of the Rotovap. Once filled, fit the flask immediately to avoid any spillage. Clean the area if allergens have been used.
  • Do not allow any distillates to foam excessively, or to travel up the vapour duct as this will potentially create cross contamination of allergen protein material. This includes the use of anti-foamer, and not overfilling the evaporating flask.
  • Use anti-foamer in all distillation runs, up to 2ml per litre, especially for items containing high protein or high fat content.
  • Once a distillation run has completed, the glassware should be washed carefully and inspected.
  • While it is not possible to distill the proteins that cause allergic reactions, every care must be taken to ensure that there is no accidental cross contamination, and that flasks and glassware is clean for each distillation run.
  • Only staff who have had training on Rotovaps and distillation should be using the machinery.
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