A yeast starter is one of the easiest and most dramatic ways to improve the quality of your homebrew. A single pack of yeast does not contain the optimal number of cells to ferment many types of beer - especially high-gravity beers and lagers. Propagating a single pack of yeast using our yeast starter kit exponentially increases the number of cells you pitch. With a higher pitching rate, you will see a shorter lag phase, lower amounts fermentation-related off-flavors, and less incidence of bacterial contamination in your beer.
Preparing a yeast starter is easy - you mix a very small batch of malt extract wort (without hops), briefly boil and chill it, then ferment it in a flask a day or two before brewing the main batch. The yeast cells from a single pack of yeast will reproduce in the starter, increasing in number from a few dozen billion cells to hundreds of billions.
The 1000 ml yeast starter kit is a great general-purpose size for five gallon batches. It features a heat-resistant borosilicate glass flask, a foam stopper, one pound of DME, and complete instructions. Making Yeast Starters