Originally By Tony Ackland
Pitching YeastsWhen the temperature of the wash has dropped below 26 °C, add the yeast. Do not add the yeast too soon - if the temperature is above about 34 °C, it will kill the yeast.
You're aiming for around 10 million yeast cells per mL of wash. A 25L wash at 1.080 will therefore need about 3 cups of slurry. Get this amount by using the slurry left over from the previous run. See the comments below in the Reusing Yeast section.
If using dried yeast, it can be helped along by letting it soak in about 1C of warm (24 °C) water for about an hour beforehand. Use a high alcohol yeast such as for champagne, or the new proprietary alcohbase or "turbo" yeasts which can generate up to 21% alcohol (who needs distillation ?). If the pack you're using is one of those small ones, it will pay to grow it up to a suitable size before using it (see Teds comments below).
Close the fermentor, and use an airlock. Keep the temperature around 28 C, and the specific gravity should drop to approx 0.980 - 0.990 g/mL and have ceased bubbling within 5 days.
Jack H recommends ..
Now... make a hole in the lid using a hammer and nail, and then widen it using sissors to the diameter of the straw. Then insert the straw so that the end of it is just in the hoke in the lid. Wax/bluetac/glue so that it is sealed. Then make the straw so that it is on a right angle (I'm assuming ur using one of those "bendy ones". Insert the second straw into this, then sticky tape and wax/bluetac/glue so that it is sealed. Make THAT straw on a right angle, so that the end of it is inserted into a glass of water. Test by adding some baking soda and vinigar to the bottle. If the gas seems to ONLY be coming out through the glass of water, it works.
Also, this is better for SMALL bottles, if ur making a big brew, i recomend u use a rubber pipe or something instead of straws
Another way of knowing how far the fermentation has progressed is to measure the weight of your fermentor & contents. Half the sugar is expected to convert to CO2 gas and bubble away. Theoretically the yield is 48.9%, but practically this is 40% because some of the gas dissolves in the wort. So if you have added 5 kg of sugar, and the weight has only dropped by 1 kg, keep it going for a while longer (you expect 5 x 0.4 = 2kg weight loss).
For excellent discussions about yeast, and how to get the best out of it, see the Turbo yeast and AllTech web pages.