A healthy Yeast colony is needed to ensure:
- Fast fermentation
- No Stuck or incomplete fermentation
- No off-flavors
- Strong colony that can resist contamination
Today we are going to discuss how to make a DIY stir plate so that one can make a large starter batch for your home brew fermentation.
Magnetic Stir plate
A magnetic stirrer can be assembled using common household articles and at a very low cost.
Yield: 1 stirrrer
- A fan (from a tower desktop PC)
- A large borosil beaker (1000 to 2000ml)
- soldering iron
- hot glue
- 3 piece Powerful magnets as these magnets rotate, they stir the magnetic stirrer as well.
- 1 piece magnetic stirrer (teflon) you can use a rod magnet encased in a waterproof plastic casing as a substitute
- 3 m wire strips for connections
- Take a 12V fan (I prefer low voltage over 220V) and strip it off its casing
- Glue 2-3 powerful mangets so that we can create a rotating magnetic field
- Allow the glue to dry and then cover it with a plate so that there is a base for the borosil yeast starter
- Give it a manual spin to ensure that there is no obstruction to the movement and then seal the setup.
- It will be good if you have a regulator to control the spin speed. The video has details of how to make the connection and make the casing for the same
- Make sure the beaker, spoons, flasks and all appraratus is sterilized.
- Take 5gm of wine or beer yeast and hydrate it in 50ml of sterlized water (25-30Degree Celsius)
- Add 2.5gm of DME (for beer yeast) or priming sugar or even table sugar. 0.25gm of yeast nutrient DAP would give the yeast enough nutrients to multiply
- Once the solution is ready, add the teflon coated magnetic stirrer and place it on the fan (stir plate)
- Turn it on and wait for the whirlpool to be created in the center. You can leave the yeast overnight to make a strong large starter batch for your brew day. (don't forget to feed them with DME)
You can stir your yeast starter for hours using this simple setup. The stirred yeast gets adequate oxygen to multiply faster and develop a strong colony. (which means you will need lesser yeast and faster ferments).