Yeast Slurry Question

dharmadog

New Member
Trial Member
Joined
Jul 29, 2016
Messages
9
Reaction score
13
Points
3
Location
St Petersburg, Florida
I have been reusing the yeast slurry from the last 2 batches of my house APA with US-05 yeast. I use a stainless steel 7 gallon brew bucket as a fermenter, and so far I have had good success with my 5 gallon batches.

My question is; should I scoop up the yeast slurry after each fermentation for storage and then clean the fermenter, and then pitch the slurry into the next batch of wort? Or should I just let the old slurry sit in the bottom of the fermenter in my cool fermentation chamber until my next batch in a week or two, and then pour the new 7 gallons of wort on top of the old slurry without cleaning the sides of the fermenter first? There is the standard amount of krausen stuck to the sides of the fermenter so I don't know if that is bad practice or not to pour new wort in a week-old "dirty" fermenter?

The slurry does sit under a small layer of APA beer inside the sealed stainless steel brew bucket at about 45 degrees f.
 
I wouldn't worry about the yeast cake, but the Krausen ring could cause a problem. I'd definitely harvest the yeast and clean & sanitize the fermenter between batches. A stainless steel ladle works great for scooping the yeast up. I'd be sure to include some of the left over beer in the storage container.
 
I've gone into the same (uncleaned) fermenter right on top of the yeast cake only when I've been able to empty it immediately before refilling it. I wouldn't trust it sitting, even in the cool, for more than a few hours. As Bob says, it's not the yeast, it's the other crud that will be a problem.
Get a dozen wide mouth pint or quart canning jars for yeast storage. When I've used a non-conical stainless fermenter, I leave a little beer at the bottom for sloshing and loosening the slurry and then take some star stan on a clean paper towel to carefully wipe off the krausen ring about half way round the pot. Then it's pretty easy to pour into waiting sanitized jars and seal up for storage in the fridge. Minimizing exposure to air and potential contaminants is the key.
 
Sound advice above I hear that stuff that sticks to the sides is quite bitter not that I've intentionally tasted it.

Since getting a conical bubble fermentor I've pitched onto a whole cake twice but can say them beers have been drinkable but not amazing :).

There's a bloke online that went a whole year brewing in one of them without cleaning it out
 
Good replies. I have reused cake without cleaning bucket but you need to remove half of yeast or you will be over pitching. This can cause off flavors you won't like. When pitching on cake, if you need to remove half of yeast then my thought is why not remove all of cake and give the bucket a scrub. On the other hand a big yeast cake is like a super starter for a big beer such as a imperial stout so. On the cake it goes. I never have had the nerve to try and wait for a week or so to reuse fermenter. That krausen ring is exposed to air for to long. Remember the co2 cap was probably lost while transferring so o2 will be in fermenter while it sits around.
 
Ah, the collective wisdom here never ceases to amaze me, thank you all.

That YouTube video alone makes me want to be less lazy than I already am.

I filled up a sanitized mason jar with the slurry at the bottom of my fermenter yesterday and put it in the fridge. I cleaned the fermenter al the same time and pitched the yeast tonight in a nice clean fermenter onto my latest batch of APA wort.

Cheers !!!
 
I've done both with success, but I find filling a jar lets me not worry about having another batch ready to go right away. Plus I find you end up with an enormous layer of yeast at the bottom that takes up a lot of space.

I usually just harvest off my starter since it's easier and less risky but I've started reclaiming Kveik slurry this way so I can be all "traditional".
 
Generally, how long does reharvested yeast last in the frige? It would make sense if you brew frequently but not so much if you brew say 6 or so batches per year. My beer drinkers have all quit drinking!
 
It depends who you ask, but I have yeast 6 months old in the fridge. A couple liter starter for a day or two and they take right off. With a 1L jar of slurry I would hazard you could just pitch right in even at 6 months. That is probably 100x the amount of yeast in a smack pack so even with die off there should be lots.
 
Generally, how long does reharvested yeast last in the frige? It would make sense if you brew frequently but not so much if you brew say 6 or so batches per year. My beer drinkers have all quit drinking!

The rule of thumb I"m using at the moment is:
  • Under a month, pitch straight from the fridge
  • 1-3 months, make a 0.5 litre starter the day before or use a vitality starter approach
  • Older, make a 1 litre starter 1-2 days before
I generally do 10 litre batches, so 19L/5 gallon would need to double those starter volumes. I'm also hoping to start using a glycol/yeast slurry in a White labs yeast tube in the freezer to keep things longer than 6 months.
 
I generally pitch slurry the day after harvesting now, but used to store some. I'd make a starter to produce ~ 300 billion cells, decant off almost all of the liquid and then fill three 50ml centrifuge vials with the slurry. I dated and used them the same as I would White Labs yeast vials. All with good results.
 
If you pitch right onto the cake not only can you over pitch but you can add things you don't want, depending on what you brewed first and what you brewed second. If you do a dry hopped pale ale or IPA and pitch right onto it, your going to add hop matter to the second batch. If you do a stout and pitch a blonde onto it, it will probably end up darker than you want. So harvesting is better. I also wouldn't trust leaving the fermenter with just the yeast in it for a week or two. It would probably be fine. But that's just probably, not for sure.
 

Back
Top