Using Yeast from the Last Batch

[BrewMU]

If I'm brewing a batch that calls for the same yeast, can I rack the 1st batch then pour the next batch into the carboy right on top of the old yeast? If so, should I use the whole thing, or pour some out?
How long will it last and how can it best be preserved? Do I have to use the cake as soon as I re-rack?
Thanks.

 

[kappclark]

Short answer - yes you can pitch directly onto the yeast cake, and it will make beer (and very quickly !)..

I think, though, you are better off washing/rinsing the yeast and pitching a portion of what you get ...

some people swear by just pitching on the entire cake. I remember the first time I did, and the next day I found the airlock and stopper across the floor and a volcano simulation going on in the carboy..but the beer turned out fine !

 

[sanch]

Short answer - yes you can pitch directly onto the yeast cake, and it will make beer (and very quickly !)..

I think, though, you are better off washing/rinsing the yeast and pitching a portion of what you get ...

some people swear by just pitching on the entire cake. I remember the first time I did, and the next day I found the airlock and stopper across the floor and a volcano simulation going on in the carboy..but the beer turned out fine !

I had a very similar experience with the explosive fermentation. washing yeast is real easy!! just do your absolute best in the sanitation department and you will reap the benefits of using your yeast to its utmost potential (and possibly saving a few bucks on yeast!!!)

 

[boist]

Not to mention that if you wash your yeast you can end up with more than you need. Divide it into two or three containers. Make a yeast starter with a portion, and store what you don't need in the fridge. Remember to use the middle, creamy layer of the wash - it's the healthiest, cleanest yeast.

 

[Boodlemania]

FWIW, I usually do a quick wash, use 1/3 to 1/2 the cake depending on OG, and save the rest for the next brew.

 

[Calder]

Use about a quarter of the cake. If you use the whole cake, there will not be much reproduction and creation of new cells. Result: Less yeast flavors (created during reproduction), and you will have old yeast doing all the work, with the potential it may finish high.

Providing there were no infection issues with the original batch, it is not necessary to wash the yeast. I wont argue that there are no benefits to washing, but it is not necessary especially if you are using the yeast immediately.

No need for a starter, you know it is healthy yeast and you will have plenty of cells.

 

[Calder]

How long will it last and how can it best be preserved? Do I have to use the cake as soon as I re-rack?

I usually pour it into several sanitized mason jars and store in the fridge. Use within a month without a starter. After a month I make a starter to check viability and for any off flavors. I have woken this simply stored yeast after 6 months and used it with no problems. If you do leave it a long time, you will get autolysis (when you smell it, you will know it). You can wash the yeast to get rid of the dead cells and off flavors.

 

[Jester]

I have just started reusing yeast to help save money. I was recently thinking about racking onto a previous yeast cake due to time restraints, but my brew day got delayed so I just washed the yeast. It was a really easy thing to do.... I was really shocked and started question why I haven't done this before. Now I have 4 little mason jars of yeast.

 

[solbes]

I just did this with a Patersbier and Tripel. Removed about 2/3 of the cake from the bucket and washed/saved the yeast. The remaining 1/3 of the cake I left as is and poured the wort of my Tripel right on top. The only cleaning I did was to remove the krausen ring from the fermentor. Tasted the Tripel when racked to secondary, it was great! I would remove at least half of the cake, or you would be overpitching in most cases.

Had activity in 2 hours, and the bucket top blew about 30 hours from pitch (while I was at work). Make sure you use a blow off if using the cake. The only other downside I see is the worry about autolysis (where a yeast wash would help). My first batch was in for 2 weeks, the tripel for 4. Seemed okay.

 

[badhabit]

Just finished four batches back to back using cake. I wash and start with washed yeast and a starter, after fermentation on batch one is complete I rack and take a cup of the cake, trying to get the center most section and pitch that into the second batch....within the hour. I have active fermentation in almost every case at about 6 hours. I will reuse from the cake 3 times total and then throw out the yeast. I do not ever use cake that has had time to sit more than an hour or so. If I am brewing the next day for example I will use new washed yeast with a starter. I will start another series of four batches tommrrow (different style and type of yeast this time)