How much dried yeast to use?

[BOBTHEukBREWER]

I use sachets of dried safale 08 yeast. I usually use the whole sachet, but for my last brew I made up a starter using one third of the sachet in 8 fluid ounces of water to which I added one heaped teaspoon of brewing sugar. Within 3 hours the starter jug had a one inch rocky head, it was pitched at 4 pm, 9 am the next day there was a thin head in the brew bucket, 9 am the next day it was fermenting very vigorously. Bottling took place on the morning of day seven. I have not yet tasted the brew. Could I use even less dried yeast to start with? I immediately reseal the sachet by folding, squeezing to expel the air and selotaping. Thanks.

 

[wilserbrewer]

Not speaking from experience here regarding using a half packet of dried yeast, but from what I have read it is a bad idea. I think the reason is that the yeast is sealed in the packet with nitrogen gas, once opened it will begin to stale regardless of how well you reseal it. But if this works well for you, great! IMO it is easier to reuse the yeast rather than making a starter every batch. Also, I have "heard" that a starter made w/ sugar will not give the yeast the nutrients they need and they will adapt to be better sugar eaters than malt eaters...IDK?

If you are looking to get extra mileage out of a pack of dried yeast, you can simply repitch the yeast slurry from the previous batch into a new batch easy peasy. I do this on occasion with good results. A bettter approach would be to "wash" your yeast after fermentation and store it refrigerated until you need it. I simply put a quart or two of yeast slurry in a freezer zip-lock bag and keep it in the fridge, and try to use it asap. I have read not to go beyond six generations...so in theory by repitching a small amount of collected yeast into a starter it is possible to get hundreds of batches from a single pack of yeast, called yeast ranching.

Personally, I've never made a starter, I either pitch dry, or repitch a collected slurry from a previous batch. Yes, I am lazy.

 

[Krelja]

no need to guess use this http://www.mrmalty.com/calc/calc.html fill in what you have and youre good to go.

 

[BOBTHEukBREWER]

Safale now market their yeast in a big drum, they think it is ok to open and close it at least 40 times. If my starter is sterile, and I add brewing sugar, vitamin B and C and build up the volume for 24 hours before pitching, I think it should be ok.