Yeast is the single most expensive ingredient that you will purchase as a homebrewer. Per unit it blows away any other ingredient. Grain is generally $2.50 and under per pound. Hops runs $2.00 and under an ounce. And we don’t really put water into the equation since it’s cheaper than anything else. Yeast on the other hand is usually $6-12 a vial or smack pack depending on the store, variety, and rarity of the yeast stain you buy. Even dry yeast runs around $3.00 a unit. For this reason, many homebrewers like to reuse yeast and thus, bring down the cost per unit of their yeast. But what happens if you want to brew a stout and then a light colored ale? There really isn’t a good way of getting all of the beer and wort separated fully.
I’ve been trying to make some strides in my homebrewing costs and I stumbled into yeast washing. The idea behind yeast washing is that you take a yeast cake, add water, and then pour the slurry into smaller containers. You then give the slurry time to separate and repeat. The heavy materials (dead yeast, hop particles, etc) will settle to the bottom and the healthy yeast will remain in suspension or layer on top of the heavy materials. You then pour the good stuff into another container and get rid of the heavy materials. Now let’s get into the nitty gritty. (more…)