Hello,
So I have a question RE: Safale -04 dry yeast, I heard/read from different forums that when you cultivate yeast you can only use it for so many generations before it loses it fermenting characteristics. I would like to know how many times can i use my Safale-04 yeast before i have to buy a new pack. The way I culture my yeast is not from racking it off of my primary. When I first got my packet of Safale 04 yeast I made a 2 starters in two 24 fl oz mason jar and I let the yeast do its thing for 2 days. I did not have a stir plate so i shook,swirl the jar as many times I could to let the yeast have as much exposure to my media. At the end of the 2 days, I then refrigerated the yeast for 24 hours to allow it to settle out of the media and decanted the media as much as I could. I then extracted the yeast into five 50 ML vials, I had a total of at least 75 ML of pure dormant yeast in vials that i planned to use for making more starters. The other jar is irrelevant because i ended up tripping over a cord and smashing the jar and losing out on AWESOME YEAST on my brew day . Anyways i ended using 4 of my 5 vials of “reserve” yeast for fermentation on my Cream Ale from northern brewer. The cream ale is in secondary right now and everything is absolutely fine with it and last Sunday I made an Irish Red Ale from northern brewer using my last vial. I made a starter from it and made another reserve vial, everything is also fine with the Irish Red Ale. So now I have this reserve yeast vial and i wanted to know how many more times can i use it before it loses its fermenting characteristics? I am thinking that i count the yeast from the first starter as Gen 1, so now i have a Gen 2 yeast how many generation do you think i could reuse this yeast before the quality starts to degrade?
If this is just a brewer myth so that people will buy more yeast frequently please let me know I am very open to any opinions.
I’ve gone 5 generations with no ill effects. I’ve also heard of others going longer. S-04 is developed to be pitched directly without a starter, the first time anyway. I can’t say for sure because I don’t have the means to prove it one way or another but that’s what Fermentis recommends. After that it’s yeast like all other liquid yeast. I like to plan my brews around the reuse of the yeast by pitching the thick slurry from the prior batch. Saves having to make a starter if I can do it within a week of racking the prior batch, and trust me I’m all about saving time & money… Cheers!!!