In order to brew some bigger beers, and to get a better fermentation in general, growing up your yeast cell count before pitching can be a very good thing. Making a starter isn’t as scary as it sounds, in fact it’s just like a mini brew day, only quicker since you’re working with smaller volumes.
The first thing to do is to get your supplies and equipment together. Here’s what I used to get my starter going.
In the back, from left to right, I have a funnel, my yeast, a stir plate, erlenmeyer flask, and a stir bar.
In the front, from left to right, I have my dry malt extract (I'm using pilsner DME), iodophor for sanitizing, and a 4 quart pan with lid.
If you’re using a Wyeast style “smack pack”, make sure you started it the night before and that it’s good and grown up. It won’t hurt anything to pitch it without smacking, but the more cells you pitch, the more you’ll get when you’re done.
Next measure out the water you’re going to use. I grow my starters in a 2l flask, and usually start with 1700ml of water.
Now start heating your water, once it’s a little warmer mix the DME in and get it dissolved, then bring it up to a boil and let it boil for 15 minutes.
The DME has been stirred in and I’m bringing it up to a boil now...
And it’s boiling. Be careful here, watch for boil overs. That will not endear you to your significant other.
Once the boil is done, chill the wort down how ever you would like. I do a two stage chill, in a sink basin filled with water. Once the initial heat has been knocked down I dump a bunch of ice in to cool it even more.
Now you’ve got time to sanitize the rest of your equipment, like your flask, stir bar, and funnel. When the wort has cooled down it’s time to set everything up. Put your stir bar in your flask, put it on the stirrer, and add the wort.
Now you’re ready to add your yeast.
Next, cover it with some foil and turn the stirrer on.
Here’s a shot of the whirlpool I get from the stirrer.
And here’s active fermentation, six hours after pitching the yeast.
Leave it on the stir plate, with the stirrer running and let it go until there are no more signs of active fermentation (typically 1 - 2 days max).
The fermentation has completed. Now move it to the fridge to crash the yeast.
This is what it looks like once the yeast has had a little time to settle. At that point it’s ready to pitch into your beer, just decant most of the liquid off, swirl the yeast up with the rest of the liquid to make a nice slurry, and then pitch!