Reusing Yeast

[Jazz2908]

I would like to start reusing yeast rather than buying a new packet for each brew.I’ve done a bit of research on how to do this but I would like to know how much of the washed yeast solution I would need add to a 23L brew and how much you would add to a starter

 

[altone]

I would like to start reusing yeast rather than buying a new packet for each brew.I’ve done a bit of research on how to do this but I would like to know how much of the washed yeast solution I would need add to a 23L brew and how much you would add to a starter

Basically, if you're washing yeast you would make a starter and build it up to the population you need for your next brew.
Ales I normally build 1.5 to 2l of active yeast solution. Lagers probably double.
This is using a stirplate.
The more washed yeast you add - the quicker your starter will be ready.
But even tiny amounts will build up over time so long as they have sugars and a little yeast nutrient.

 

[Roosterboy]

Can I suggest you get conical flasks and better storage containers than screw top glass jars that don't have a good seal.

 

[Lionman]

You don't need to do starters if you are harvesting enough yeast. They can be a good idea though if your unsure of the volume you have or want to ensure they are active after they have been in the fridge for a while.

I can usually end up with a good 100ml of compressed white yeast on the bottom of a flask after washing a few times and removing the heavier trub. This from the cake of a 40L batch.

If I add this to 40 odd litres of well oxygenated wort then it takes off in about 6 hours and there are no signs of lag or under pitch. This is yeast that is only hours from harvesting though. This appears to be quite a bit more yeast than 4 packets of dry yeast but an overpitch is always better than an underpitch.

Get a erlenmeyer flask or two that can fit the majority of a yeast cake in it. It will make life a lot easier and your recovery rate will be a lot better. Regent bottles are also the way to go for storing the cleaned yeast.

 

[Rocker1986]

I harvest my yeast from my starters so I don't have to muck around washing yeast out of fermenters. The harvested yeast sits in mason jars in the fridge. I much prefer this method, but it does require a bit of maths if you are more pedantic than "this size for ales and this size for lagers" like I am. It's also good for predicting approximate harvested cell counts,and I know it's not precise but it's ballpark which is close enough. It's all based on stirred starters as I have a stir plate.

Basically all I do is work out what size starter I need to make to be able to harvest 800mL of it and still leave enough cells behind to achieve the desired pitch rate into the batch, using the Troester stir plate setting on YeastCalc. As an example, my latest one which I just harvested from today was 2.1L in size, so 1.3L for the actual starter with the other 800mL going into the mason jar to settle out for next time. The whole 2.1L was predicted to have netted just over 410bn cells from a starting amount of around 130bn from memory, so I was able to harvest approx. 160 bn cells and leave the other 250bn or so for the batch, which I'm pitching tomorrow. The batch only called for about 220bn cells but I like to go over a bit just to be sure.

Everyone has their preference for how they re-use yeast though. It may not be perfect but I just find this method simpler than washing it. I've been able to re-use yeast from the original purchase for over 2 years doing this without any noticeable difference to the beers fermented with it, so I don't buy yeast very often at all anymore.

 

[wide eyed and legless]

I would like to start reusing yeast rather than buying a new packet for each brew.I’ve done a bit of research on how to do this but I would like to know how much of the washed yeast solution I would need add to a 23L brew and how much you would add to a starter

A good thread here from wolfy. https://aussiehomebrewer.com/threads/rinsing-yeast-in-pictures.55409/