Cleaning Glassware

Since you will be using several pieces of glassware, cleaning them after use can became an issue.

Even though specific detergents are available, I think regular automatic dishwasher detergent dissolved in hot water is more than adequate.
These detergents usually contain sodium metasilicate, and are designed to be very effective at high temperatures. They also do not require excessive rinsing.

At times it might be necessary to scrub away stubborn organic residues with a bottle cleaning brush.

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Heat Sterilization

Microbiological manipulations require sterility.
This means that every form of life, even spores, should be removed from objects that come in contact with wort or yeast.
Sterilize your tools and glassware in advance, so you will have a supply of sterile containers ready when you need them.

We can achieve sterility either with dry or wet heat.

Dry heat

To sterilize an object with dry heat, you need to place it in an oven at a certain temperature for a certain time.
Authors of textbooks on microbiology do not agree on the temperature and time required, but I find the recommendations of the UK Department of Health quite reasonable: 45 minutes at 170 °C.

Obviously this procedure can be applied only to objects that can stand such conditions.
Glass pipettes are good candidates, as they are generally too long to fit into a pressure cooker.

To sterilize a pipette, first you must substitute the cotton plug on the mouth side. Then wrap the pipette in aluminum foil, to preserve sterility until you need to use it.
Place in the oven and slowly rise temperature to 170°, then keep for 45 minutes.
Turn off the oven and let cool very slowly to avoid breakage due to thermal stress.

Wet heat

Sterilizing with wet heat (water vapor) is the most common method to obtain absolute sterility. It is also the most effective, since spores can resist dry heat, but 20 minutes of exposure to steam at 121°C will kill anything.
pcooker Such temperature can be reached by pure water vapor under the pressure of 15 psi or 1,05 Kg/cm2 in an autoclave or pressure cooker.
Notice I said pure vapor: if the atmosphere inside the pressure cooker is a mix of air and water vapor, the temperature would be lower.
This means that you should let the steam escape from your cooker for a few minutes before closing the valve, in order to expel the air.

CAUTION Remember that a pressure cooker or canner, if not handled properly, can become a dangerous object: read and follow the instructions that came with your cooker.

As a general guideline:

  1. Pour hot water in the cooker up to a level of 3 cm from the bottom.
  2. Place the objects to sterilize inside the cooker. I suggest you wrap the objects you want to autoclave in aluminum foil. Thus when you need them you won’t have to worry about dust or external contamination: just discard the foil and use them.
  3. Close cooker and leave valve open. Apply heat.
  4. When steam begins to vent, wait 5-10 minutes then close valve
  5. Wait until required pressure (15 psi or 1,05 Kg/cm2) is reached, then start timing.
  6. After 20 minutes remove from heat and let cool naturally down to room temperature. Do not force cool.
  7. Open cooker, remove objects and store in a clean place until needed.