Home Brewing Lesson #04
How to make a yeast Starter:
If you are planning to use a liquid yeast culture such as a vial of White Labs Pitchable Liquid Yeast or one of the smack-packs, making a yeast starter can be beneficial to your fermentation for two primary reasons. The first reason is that your yeast will multiply to a level that will be more appropriate to fermenting 5 gallons of beer. The second reason is that the yeast will be active and ready to go when you pitch it to the wort. This process should be started 36 to 48 hours prior to brewing time.
What you need (pictured above):
#1 - pot for boiling water
#2 - one cup of dry malt extract
#3 - glass container for the yeast starter (sanitized)
#4 - one quart (32 oz) of water
#5 - liquid yeast culture
#6 - thermometer
#7 - funnel (not pictured)
#8 - air lock (not pictured)
Step #1: Boil one quart of water
The purpose of boiling the water is to kill any bacteria that may be present and provide a hot water base for dissolving the dry malt extract. Once the water starts to boil, let it boil for 5 minutes or so and then remove it from the burner.
Step #2: Dissolve the dry malt extract in the hot water
Remove the boiling water from the burner and add the dry malt extract.
Stir it in until it is completely dissolved.
Return it to the burner and let it boil for 5-10 more minutes. Pay close attention to this boil, because when the malt extract solution starts to boil again, it might want to boil over. When you see the foam start to rise, remove it from the burner until it settles back down. You may have to do this several times before the solution settles down into a nice rolling boil. While the extract solution is boiling, prepare an ice bath in the sink.
Step #3: Cool the malt extract solution
Place the pot with the extract solution in an ice bath and let it cool.
When the solution has cooled to less than 75 degrees or so, you can remove it from the ice bath and transfer it to the yeast starter container.
** IMPORTANT **
Anything that touches the malt extract solution after it has been boiled and cooled MUST BE SANITIZED. Everything should be clean before you start, but using a sanitizing solution such as Iodophor or Star San is required after that.
Step #4: Aerate
After you transfer your extract solution to your starter container, shake it up really well to oxygenate the solution as much as possible.
Step #5: Add the yeast
After your starter solution has been nicely aerated, dump in the liquid yeast solution and shake it up a little more.
Step #6: Put on an air lock
The air lock must also be sanitized prior to use. The air lock lets gasses out of the starter container but doesn't let anything back in. Some people prefer to use a liquid like vodka because it doesn't promote bacterial growth. If your air lock is properly sanitized, you can used bottled or distilled water, or water that has been boiled.
Step #7: Wait
Put the yeast starter container away somewhere out of the way, preferably in a dark area. Periodically, you might want to pick it up and swirl it around a little to stir up the yeast that will settle to the bottom of the container. Within 24 hours or so, you should see some occasional bubbles in the air lock. Be careful not to shake any of the water from the air lock into the starter solution when you periodically agitate the starter.
Step #8: Pitch the yeast
If you started your yeast starter 36 to 48 hours before you started brewing your beer, it should be ready to pitch to the wort when you finish cooking. Remove the air lock from the yeast starter container and shake the solution up again to re-suspend all of the yeast that may have settled to the bottom of the container and then dump it in your fermenter with your newly-cooked wort!
Note:
Some people prefer to NOT shake up the yeast starter solution before pitching to the wort. Some like to drain off the top liquid and just pitch the yeast at the bottom of the starter container. I generally pitch the entire starter because it has active yeast suspended in it. It's simply a preference issue...














