How To Make A Starter
Whenever you're making a batch of beer, one of the prime ingredients is yeast. Without yeast, your brew will simply be sweet liquid with bitter, hop overtones. To get the sweet liquid to turn into alcohol, you need yeast.
The yeast eat the sugars, with two resulting byproducts: Carbon Dioxide and Alcohol [actually, there are more byproducts - some good, some not-so-good].
The yeast also add to the distinctive flavor of your brew. There are almost as many varieties of yeast as there are varieties of beer.
Clearly, yeast is important to the outcome of your beer.
After you have boiled and cooled your wort, your brew is in a very vulnerable state. It is just the right temperature (between 70F and 85F) for a number of "nasties" to take hold in your brew. Wild yeast. Bacteria. Mold. You don't want these to influence your beer's final outcome. A quick, vigorous fermentation [under 12 hours] ensures your beer will come out as expected.
This is why we use starters. They increase the yeast cell count to levels that make it more likely that the yeast will ferment your beer and not some other foreign substance.
Generally speaking, for a 5 gallon batch of beer, you want to pitch in the neighborhood of 200 billion yeast cells. The Wyeast and White Labs "pitchable" tubes only have 50-60 billion cells - around a quarter of what is necessary to ensure a prompt fermentation.
What follows is the step-by-step process I follow when making starters. It is heavily influenced by the page on starters by Mike Uchima.
First, you need some wort. I generally have two ways of obtaining it: I make an extra couple of gallons or so of wort when I'm brewing, or I just buy some Dry Malt Extract (DME), add some hops and I'm good to go.
In this first picture, I've taken two pounds of DME and two gallons of water to make a wort. I added a half ounce of hops. I then cooled the wort, and put it into individual ziplock bags of 650-700ML each. I then place the date on the bag, and throw them in the freezer. When I need to make a starter, I pull out a bag the night before to thaw [place it in a bowl just in case you have a leak].
Next, pour the contents of the ziplock into a flask. Trust me on this: spend the money and get a flask made of borosilicate type glass. You are going to be subjecting this flask to extremes in heat and cold. Regular glass just can't take the stress without breaking. A 1 liter flask will run you around $10.
Cover the opening with aluminum foil, place the flask on a burner [gas works better than electric, but I've done it with both quite well], and bring it to a slow boil. Medium heat at the most. This will take a little longer, but it's better than having to clean the burners of dried-on wort! Let it boil for 5 minutes.
After the boil, USING A TOWEL [or welder's gloves like I use], move the flask to the sink and fill with cool water to the level of the wort [any higher, and the flask will start to float and may tip over]. Drain the water, re-fill half way, then fill with ice. An occasional swirling of the flask should have it cool enough in about 15 mins.
You now want to pick up the flask, place your hand on top of the foil and shake the crap out of the wort [do this over a sink]. You should get a very foamy head inside of the flask.
Take your yeast, pour it into the flask and cover with a drilled stopper and airlock.
You now want to cover the flask with a towel and place in a warm, draft-free area [I leave mine in the corner of my kitchen counters].
Let your starter run for at least 24 hours. Don't expect a lot of activity like you see with your 5 gallon batches of beer. Sometimes the entire fermentation cycle will take place over night with little more than a few bubbles from the airlock or a little krausen on the top of the wort. Don't worry.
When it's finished, you should see a pretty good layer of yeast at the bottom of the flask.
When you're ready to ferment your 5-gallon batch, simply swirl the flask to incorporate all of the yeast into solution and pitch into your well aerated wort.
With this process, I normally see positive pressure on my airlock within 3 hours and active bubbling within 4 hours. A good healthy start to my brew....
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