The purpose of this procedure is to transfer one or more yeast colonies grown on a solid media to a test tube containing a liquid media, maintaining sterile conditions.
The liquid media could be sterile distilled water for long term storage, or sterile wort for fermentation and propagation.
The usual precautions apply: scrub the table surface, the test tube and your hands with alcohol. Wear a mask, keep your work area as dust-free as you can, work in flame zone.
Since you need to work as quickly as possible, you should practice with empty test tubes ahead of time, to gain the necessary dexterity.
Examine the colonies on the plate and select a few round, healthy, well isolated ones. You can mark them with a felt tip pen on the bottom of the dish.
Place on the table the Petri dish upside down (media on top, cover on bottom), test tube with liquid media (standing in its rack), inoculation loop.
When ready, proceed as follows:
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The plate is about useless now, and you can discard it.
If you are preparing a master for storage, you can wrap the tube in aluminum foil, label it and store in the refrigerator.
If you inoculated a tube of sterile wort, you should incubate it in a warm (>27 °C) dry clean place. Expect signs of fermentation within 12 hours. Crack the cap open to release CO2, then proceed with starter propagation or plate again for further selection.
Use this procedure to step up a starter.
That is, to transfer fermenting wort from one flask to a larger one containing more sterile wort.
The usual precautions apply: scrub the table surface, the flasks and your hands with alcohol. Wear a mask, keep your work area as dust-free as you can, work in flame zone.
Proceed as follows:
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Use this procedure to prepare a sterile flask with canned sterile wort for use as a starter.
That is, pour the content of a previously canned wort jar into a sterile flask.
The usual precautions apply: scrub the table surface, flask, jar and your hands with alcohol. Wear a mask, keep your work area as dust-free as you can, work in flame zone.
Place on the table a sealed jar of sterile canned wort and a sterile flask of the appropriate size.
When ready, proceed as follows:
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When the flask is a large one, say 1000 ml, a considerable amount of CO2 is produced during fermentation, so you might want to use an airlock.
The flask would probably have been autoclaved capped with aluminum foil, and the airlock and rubber bung would have been soaked in a disinfectant solution.