hope this was somewhat helpful. And I am sure someon else on here can comment on you washing and pitching questions.
Whitewater Brewing Co.
Of course, sanitation is very important. I clean and sanitize everything that touches the yeast slurry. I'll re-use yeast 4-5 times this way. If I'm pitching a jar of yeast I captured from a previous batch, I don't even bother making a starter. After all, the only purposes of a starter are to ensure the yeast is viable and to build up the necessary cell count. If the yeast is only a couple of months old and the batch I took it from turned out fine, then I assume the viability is good. And pitching 1/4 of a yeast cake is more than enough cells (I actually end up with about 1/2 - 3/4 cup of dense yeast pack in the bottom of each jar, which even by conservative estimates, is several hundred billion cells). So far, every batch I've done this on has taken off vigorously. That said, I also discard any yeast that's been in my fridge for more than 3 months.
The yeast divide to some extent in the beer while they ferment. A beer pitched properly should still get a 4-5 fold increase in yeast numbers. So splitting into 4 is about perfect, in terms of having an appropriate amount to pitch later.Deanwttck wrote:I've watched videos where a person collects all the yeast , etc, after brewing, then washes the yeast, divides it up into 2-3-4 containers, then dumps one of these containers of yeast into their next batch to start fermentation. Am I wrong, but wouldn't there be only a 1/4 (if using one of the 4 containers) of the yeast used in the original batch?
I don't often wash yeast, but I would strongly recommend that if you do, you run the washed yeast through a starter (with stirring and all that). E.G. throw the ~1/4 to 1/2 cup of slurry you get in each jar into 1.5L or so of fresh 1.040 wort. Yeast coming out of a beer are a little stressed, and if you don't occasionally run them through a starter will eventually weaken to the point that they do not ferment well. Using a starter every time prevents this, but you'd probably be safe to do one or two batches in a row without using a starter.
Someone plugged by blog already - I don't actually have anything on yeast washing on there, but there is some info on starters you may find useful.
EDIT: I do have a lot of info on freezing yeast. This is something you may want to consider if your yeast prices remain high, but I'd recommend holding off on this until you are more comfortable handeling yeast and working with starters. I'm preparing some new videos to help people farm yeast at home, so stay tuned....
Deanwttck wrote: I've also watched people using a new packet of yeast,using this yeast in a yeast starter,then pouring that in to start ferm.
I assume these were wyeast smack-packs. Dry yeast normally just need to be briefly rehydrated with water. Smackpacks from Wyeast, and tubes from White Labs (collectively known as "liquid yeast") only provide about 100 billion cells, approximately 1/3rd that normally required for an average ale. The starter allows you to get those numbers up to the proper amounts. Dry yeast (danstar, safale, etc) have more than enough yeast in the packet; the water re-hydration helps them survive being dropped in the beer. Without rehydration you may loose upto 50% of the yeast you pitch.
You can assume its enjough (it usually is), or you can guestimate based off the thickness of the sedimented yeast layer. There are calculators out there for estimating yeast numbers in sedimented yeast.Deanwttck wrote:If you used (as mentioned earlier ) one of these 4 containers in a yeast starter , how do you know if there is enough yeast to get things finished properly?
$15 is a lot for liquid yeast; ontariobeerkegs can probably mail you a vial for a few dollars less. OBK sells out of shop for $7 or $8 (I think).Deanwttck wrote: I guess what I'm asking,if you use 1/4 of the original yeast in a yeast starter, do the number of yeast increase in a yeast starter? Also, how long would would the washed yeast be good for,if kept in the fridge? I've looked at some beer recipies that call for two packs of yeast for their brew. It never occurred to me that more than one was ever needed. I live in winnipeg,and at a brew shop i asked how much a good quality liquid yeast was, and he said $15.00,i started looking around for one of those defribulators! Until now all the beer i made was from beer kits that throw in a pack of coopers dry yeast, but i want to get into extract/all grain.Can someone help me out with these questions?
Whitewater Brewing Co.
In terms of generations, the answer is 'it depends'. If you are not running the yeast through a starter every 2-3 generations you shouldn't use it more than 4-5, assuming normal strength beers. Without an oygenated starter the yeast will run out of unsaturated fatty acids and sterols, leading to poor fermentation after the 4th or 5th generation.
If you are using a starter you can, in theory, propagate the yeast indefinitely (barring infection, etc). But as a rule you don't want to go past 10-ish generations, as the accumulation of mutations will alter the yeast flavour profile, leading it to produce a beer that tastes different (and may have other differences in things like inoculation or attenuation) compared to the parental strain. Some people deliberately go past 10 generations in order to get a "house strain" of yeast, in which the unique characteristics that develop in the yeast become their house flavour.
If you want to propagate a yeast indefinitely without flavour drift you need to use frozen stocks - this way you can keep a low-division frozen stock as your 'base', and grow batches of yeast from that. This keeps the generation numbers low - but obviously requires a great deal of yeast-handling experience and some investment into equipment.