is it simply liquid fermented dow dehydrated at low temperature?
Alternatively you can learn to like Marmite - a yeast based spread (at least in the UK) Mmmm nice - but that is a matter of opinion.
Learn to like yeast flocks, ginger beer or marmite for sure but to do the focks yourself?Thats the question...:)
http://www.popsci.com/node/29564 It seems that yeasts flock by themselves.
Yeast - at least bread making yeast - grows quite well in a warmish 4 deg C to 28 deg C obviously faster at the warmer temperature.It needs food and for extracting yeast I would feed with a spoon or 2 of sugar every day o when activity starts to flag.Dissolve yeas in hand warm water add sugar - Wait and hour or so.Make sure the container is big enough because it WILL grow and expand and froth.As a side issue if it matters to you the yeast will also produce alcohol and CO2 gas, oh and more yeast.A favorite way to do this is to "grow" a ginger beer plant"From BBC cookery pages"There are two ways of making ginger beer. The first consists of shredding ginger root and boiling it up with water and sugar. The second involves making a ginger 'plant' which can be re-used time and time again. This makes a batch once a week. The brewing process that will be discussed in this entry is the latter.Equipment and IngredientsEquipment A jar and lid which is big enough to contain the plant. One pint-sized measuring jug Several clean and dry two-litre plastic bottles. Teaspoons A large pan A fine cloth for straining the plantIngredients Dried ginger Dried yeast Sugar Juice of four lemons WaterMaking the PlantThe plant is a mixture of dried ginger, yeast, sugar and water. This creates a yeast culture. In the jar, place one teaspoon of dried yeast, two teaspoons of dried ginger, four teaspoons of sugar and a pint (600ml) of cold water. Stir and keep at room temperature. Feed the plant every day with two teaspoons of dried ginger and four teaspoons of sugar. Stir after feeding. The plant will be ready after one week.Making the Ginger Beer Place 1kg (2lb) of sugar and two pints of boiling water in the large pan. The sugar will dissolve. Add the juice of the four lemons to the pan. Strain the contents of the jar - the plant - through the cloth into the pan. See below for what is to be done with the solid portion of the plant. Add 14 pints of room temperature water. Stir and bottle. Fill the bottles about seven-eighths full as you need to allow for expansion. Squeeze the air out of the bottles to stop them exploding under pressure from their contents. Store the bottles in a safe place at room temperature, and leave for three to four weeks to 'brew'. Discard half of the solid from the plant or give it to someone so they may start their own. Place the remaining half in a clean jar with a pint of water and continue to feed as above."