Reusing yeast

[Djangotet]

If I wanted to reuse yeast every time I brew, I have heard that you don’t want to use the full cake for your next batch. I originally was planning to ferment in a keg and reuse the same yeast without opening the keg between batches. Now I’m wondering what the best option is. If I have just finished a beer and I want to brew one with the same exact OG should I remove 30% with a sanitized measuring cup and leave the yeast in the keg till the next batch? Or should I pull out just a bit and put it in a starter flask? What would you do if you had transferred your beer out and the keg was filled with yeast?

My goal is to reuse the same yeast until I see the yeast mutate. I want to make something unique and I would add yeast nutrients to each brew. I plan to keep the yeast as clean as possible by very lightly filtering beer on the way in and by dry hopping in a separate keg off the yeast. The only thing that will touch the yeast is my beer and I plan to brew similar styles over and over till I master them. Thanks! I’m a total noob so sorry if I’m asking dumb questions, I read some other forums but I’m wondering about my specific process.

If I scoop out a good amount using a sanitized measuring cup and I put it in a sanitized mason jar, can it keep just like that or would I need to add liquid? If I use a light filter and don’t dry hop onto the yeast, is yeast washing still necessary?

Any better suggestions for how I can keep the yeast from my first batch clean and sanitary and healthy between batches?

 

[Zambezi Special]

I just pour the cooled down wort on the previous trub.
These days that's a bit cleaner as I am using a hop spider now. But before that, just on whatever remained in the fermenter.
And if I didn't (don't) feel like brewing, I put apple juice on it (preserved with vitamin C).
I'm sure there are much better ways, but it works for me. Note that I am not a super taster and I don't compete.

 

[Miraculix]

You got wrong information. You actually want to throw the beer on top of the whole yeast cake if you can. Asap after bottling/kegging the previous beer. You got most healthy and most active yeast, meaning that your next ferment will be probably better than the previous one. There is not really such a thing as an overpitch.

 

[Protos]

@Miraculix you think so?
I believe that pitching on a full cake fits only huge beers or Lagers. In Ales, we rather need some esters, and they turn out somewhat dulled when the growth phase is shortened or absent (as it happens when overpitching). My experience seems to corroborate this, so for ales I use usually 1/3 of the cake, and for the more characterful styles, like Saison or Weizenbier, just 1/4 of the cake, removing the rest of the yeast even when I pitch into the same sloppy fermenter.

 

[Protos]

I put apple juice on it (preserved with vitamin C)

Is there some advantage in using Apple Juice over the wort fermented by the same yeast cake?

 

[Miraculix]

@Miraculix you think so?
I believe that pitching on a full cake fits only huge beers or Lagers. In Ales, we rather need some esters, and they turn out somewhat dulled when the growth phase is shortened or absent (as it happens when overpitching). My experience seems to corroborate this, so for ales I use usually 1/3 of the cake, and for the more characterful styles, like Saison or Weizenbier, just 1/4 of the cake, removing the rest of the yeast even when I pitch into the same sloppy fermenter.

Yes, this seems to be the internet wisdom. However, my English ales, my lagers, my us ales, my saisons, basically everything except hefeweizen (didn't brew one yet) turned out better with pitching directly on the yeast cake than the initial beer. Other brewers here confirmed that.

 

[hottpeper13]

Here's what I found out after buying a bright field scope and related stuff.
Go to Brewdads yeast calculator and input your first step. If a 1.050-1.060 you should only need a single step. Look at the growth factor column on the end , it should be between 3-5 times,that is the number micro biologists have found to give the most viable yeast.
Now make a second step but make it 20 L and no stir plate(fermenting a beer). Do two things ,look at the growth factor and cell count. Take the cell count the program told you to pitch and divide it into the 20 L cell count and that is how much you need to repitch. This SOP is for cereal repitching batch to batch in order to maintain viable yeast. I go thru 4 or so generations before I pitch the last one on the cake and that one is 1.090-1.134,and then i compost the yeast.

 

[Zambezi Special]

Is there some advantage in using Apple Juice over the wort fermented by the same yeast cake?

Yes. You get cider
I like cider and beer.
I bottle and straight away use the yeast cake. Maximum 2-3 hours later. So if I don't brew beer that day, I make cider.
I hate throwing yeast away!

 

[Miraculix]

Yes. You get cider

I would say, that is a pretty good advantage!

 

[Protos]

my English ales, my lagers, my us ales, my saisons, basically everything except hefeweizen (didn't brew one yet) turned out better with pitching directly on the yeast cake than the initial beer

Mine is entirely opposite experience... All my "full-cake" beers tasted duller, with estery profile slightly muted, so I started to split my cakes in three and never looked back.

We just may take different meaning of "better"

 

[Zambezi Special]

I got more or less the same experience as Miraculix.
But I think only a side by side comparison will give the answer.
And it is of course personal. Everyone's tastes are different (luckily)

 

[Miraculix]

Mine is entirely opposite experience... All my "full-cake" beers tasted duller, with estery profile slightly muted, so I started to split my cakes in three and never looked back.

We just may take different meaning of "better"

I musst admit, I only have direct comparisons for English ales and for the clean lager/us ale yeasts. The other ones were different beers to follow on the yeast cake. But for these three, more is definitely better for the yeasts I've tried (at least according to my taste buds).

 

[odie]

so you are keg fermenting?

well here is what's happening with the yeast cake...

a full length dip tube is going to expel most of the yeast cake on the first pint or two that you attempt to drink. Don't worry, plenty of good yeast is still inside, just not around the tube anymore.

If you are using a floating dip tube, then all the yeast remains in the keg until that last pint or two, when the float hits bottom and blow a lot of it all out.

either way, when the keg is empty, most of the yeast cake will have been expelled. But there is still plenty of yeast remaining inside the keg for another beer. Just open the keg and dump fresh wort into the keg and close the lid.

you can do this over and over until you get tired, or an infection gets in (unlikely) or the yeast mutates (unlikely to happen before you get tired of that beer).

Just make sure you keep the keg cold between it going empty and fresh wort getting added. Best is to brew a new batch as soon as the keg blows.

 

[hottpeper13]

Never thought of that, good call Odie.

 

[Beekeeper]

cereal repitching

A: cereal repitching
B: surreal repitching
C: serial repitching
D: None of the above.

 

[VikeMan]

There is such a thing as overpitching, and the potential consequences are well documented. One of those consequences is reduced esters, dues to lack of growth. Whether it's a good thing or a bad thing can be both circumstantial and subjective.

I like most of my ales pitched at about 750K cells per ml per degree P, but I'll pitch less (for hefes and other beers where I want to increase esters) or more (for big imperial stouts, for example, where I want as "clean" a fermentation as possible).

 

[hottpeper13]

I like the cereal repitch with toast for breakfast.

 

[VikeMan]

I like the cereal repitch with toast for breakfast.

You want yeast with toast for breakfast? Here you go:

I can smell the autolysis from here.

 

[Miraculix]

There is such a thing as overpitching, and the potential consequences are well documented. One of those consequences is reduced esters, dues to lack of growth. Whether it's a good thing or a bad thing can be both circumstantial and subjective.

I like most of my ales pitched at about 750K cells per ml per degree P, but I'll pitch less (for hefes and other beers where I want to increase esters) or more (for big imperial stouts, for example, where I want as "clean" a fermentation as possible).

I'd say that in most cases "overpitching" is beneficial and most of breweries seem to be doing it, at least in UK and lager breweries in Germany. Pitching not enough healthy yeast might increase ester production but it also increases levels of unwanted substances and the chances of infections. My bad beers were surprisingly often also low cell count beers. The best were considered overpitched, by homebrew standards.

 

[VikeMan]

I'd say that in most cases "overpitching" is beneficial and most of breweries seem to be doing it, at least in UK and lager breweries in Germany.

My experience in the USA is the opposite, i.e. that (small) commercial breweries tend to underpitch rather than overpitch (compared with defacto "standard" pitch rates).

I do agree that the potential consquences of severe overpitching tend to be less objectionable than the potential consequences of severe underpitching.

 

[redrocker652002]

Sorry to revive an old thread, but this is something I have been thinking about. I am thinking of trying to ferment in my serving keg, but I do dry hops on a lot of my brews. As I am reading this thread, I am thinking that, as long as the yeast seems healthy and there was no off tastes in the brew I had in there, I can just pour the wort over the yeast at the bottom of the keg, seal it up, add a blow off tube and let it go? That is very interesting to me. How would I measure my gravity or how would I add a monitoring device like Ispindel or the new Paato airlock? Do the tap lines need to be cleaned and sanitized? Interesting stuff. Rock On!!!!!!