Make a Yeast Starter

Whether you use dry or liquid yeast, making a yeast starter is a very smart step to take in order to insure that all your hard work at the kettle won’t be in vain due to low viable yest cell count. It’s also a nice way to wake up the yeast and get them ready for the all-u-can-eat sugar buffet that they are about to embark on in your wort. Some don’t see the point of starters. Having once been in that camp, it only took one time of making a starter to see the benefit. If you just look at some of the math in your more respectable brewing books, it breaks down to needing about 180 billion cells for about 5 gallons of wort with a starting gravity of 1.048 for an ale, a bit more for a lager. Wyeast and White Labs contain somewhere in the neighborhood of 70 to 120 billion cells, so even if you have the most viable pack/vial you can find, your still a little shy of “ideal”. But really, just do what I did and take the “Pepsi Challenge” – make a 10 gallon batch of brew and split it in two carboys (or buckets). Pitch one with a starter and one from the vial or packet and see how long it takes for activity to start. If you don’t have a 10 gallon single brew session capacity, just try one 5 gal batch with a starter then the next time you brew that beer, just pitch the vial or packet. I bet you’ll see that spending a very small amount of time making a starter will be well worth the effort.

You’ll need the following equipment for pitching enough yeast for a 5 gallon batch of 1.048 to 1.070 starting gravity:

  • A 1000 ml Erlenmeyer Flask. These are available from many homebrew shops or lab equipment supply store
  • Some light (or ultra-light if you can get it) DME (dry malt extract)
  • Yeast nutrient, again available at homebrew shops
  • A 4 qt sauce pot
  • A bowl large enough to make an ice bath for the finished starter. It should have enough volume to bring the ice bath up to the level of wort in the flask
  • Aluminum foil
  1. Clean your pot and flask as you would any brew equipment. You are, after all, making a little batch of wort. You also want to have your yeast at about room temperature so pull the vial or packet out of the fridge so it can come up to room temp before you pitch. Same as you would if you were pitching directly into your carboy or bucket
  2. Add a little over a liter of water to your sauce pot and turn on the heat. Your objective here is to boil down to between 900 – 1000 ml
  3. Add 1/2 cup of your DME and stir it in until disolved
  4. Add a pinch of yeast nutrient and stir that in as well
  5. Bring the wort to a boil and hold for 15 minutes. No need to go bonkers, just keep it at a soft boil we’re not trying to get any hops moving around in here (note: you can do all of the above steps in the Erlenmeyer flask, but I always have problems with boil-over so I find it FAR easier to do this in a separate pot. I do often boil some water in the flask while the above is happening, just to make absolutely sure it’s sanitized then discard the boiled water before the next step)
  6. Pour the wort into the Erlenmeyer flask
  7. Dunk the flask in an ice bath and cover the flask with a piece of aluminum foil.
  8. Swirl the flask around in the ice bath every 5 minutes or so to cool the liquid a bit faster and add more ice if necessary. You want to have your ice bath as could as possible.
  9. After about 15 or 20 minutes you should be at your pitching temp (about 75 – 80 degrees Fahrenheit/24 – 26 degrees Celsius), use a sanitized thermometer to confirm. If you managed to get the wort lower than the above temp, take it out of that bath and let it come up to about 75F/24C before pitching. You don’t want to shock the yeast
  10. Pitch your yeast and give it good swirl to get all the yeast into solution
  11. You can either swirl the wort for 5 minutes to aerate, or inject with O2. Either way, you want to spend a moment aerating. Cover the flask again with the foil (no need for an airlock) and put it in a place that will maintain the pitching temp for about 12 – 18 hours.
  12. If you have a stir plate (and if you do, you’re probably not reading this) set up your stir plate and get the yeast moving in a very small vortex. You don’t want them riding a tilt-a-whirl, you just want them to stay in solution. If you don’t have a stir plate, fear not, just drop by your starter once in a while over the 12 – 18 hours and give it a good swirl to get the yeast moving again. All this is just to encourage cell growth. I don’t have a stir plate and I still get fantastic results every time.

That’s it. After 12 – 18 hours you will have a very healthy cell count (in the neighborhood of 200 billion cells) and the yeast will be raring to go! When I pitch the starter, I don’t bother to decant it, I just swirl it up to get all the yeast in solution and pitch the lot into the wort. Happy brewing!