Can I referment on top of the yeast once I rack out?

[drrader5]

I was going to brew a new batch tomorrow, and rack my current batch into my secondary. I was thinking about putting my new batch into the primary with the current yeast that is in it. Does anyone see any problems with doing this, this particular yeast has been awesome?

 

[Revvy]

It's quite common.

 

[el_horno]

Like Rev says quite common, and you will be impressed with how quickly and vigorously fermentation begins. It still impresses me!

 

[Revvy]

Like Rev says quite common, and you will be impressed with how quickly and vigorously fermentation begins. It still impresses me!

Yeah, even within a day.Someone posted in a thread yesterday that it had been 36 hours and he didn't see any "activity." And was worried, and of course we told him the only activity that was accurate and meant anything was a decrease in gravity as monitored by a hydrometer reading.

He took one (which he should have done before he started a panic thread) and it turned out it was fully done.

 

[Yooper]

I've done it in the past, with pretty good results. I always did it going from a small beer (like a 4% ABV beer) to a bigger beer (like a 9% ABV beer). I never had any problems.

But then I started learning more about yeast and reproduction and yeast health, and checked pitching rates. Normally, just about a cup of the yeast cake is actually enough for the next batch but I use a yeast pitching calculator (like mrmalty.com's) to make sure it's the right amount.

Normally I can use a cup of the yeast in the next batch, and save the rest in sanitized mason jars, so I get about 10 batches out of one package of yeast.

Here's some info on this: https://www.homebrewtalk.com/f163/why-not-pitch-your-yeast-cake-166221/ and https://www.homebrewtalk.com/f163/yeast-washing-illustrated-41768/

 

[drrader5]

Sounds good, I had my airlock going crazy within 10 hours of pitching the yeast so I thought it would be good to use again, and the only thing special I did was make a yeast starter. The batch I brew tomorrow will only be my second batch ever, so I tend to come up with questions. I really appreciate everyone being willing to give advice.

 

[Jints07]

If you are brewing two different types of beers how do you avoid mixing the "flavor" from the first beer with the second? I.e. isn't it the case that there will be some hops material and sludge mixed with the yeast cake from the first batch? I'm a total newb so forgive me if this question is dopey.

 

[Yooper]

If you are brewing two different types of beers how do you avoid mixing the "flavor" from the first beer with the second? I.e. isn't it the case that there will be some hops material and sludge mixed with the yeast cake from the first batch? I'm a total newb so forgive me if this question is dopey.

It's not dopey at all!

First, if you do reuse the yeast cake (or a portion of it), generally the flavor from the impact from that tiny amount of debris is unnoticeable. It's a small amount, and you're generally putting 5 gallons of wort into it. So it's a minimal flavor impact, if any at all.

Secondly, I normally do NOT use the entire yeast cake. I often use the process I linked to above called "yeast washing illustrated", where you rinse the debris from the yeast cake and just keep the nice yeast. Then I put that yeast in about 4-6 mason jars and store in my fridge. And each one of those jars makes about 2 batches of beer for me.

 

[BigFloyd]

Secondly, I normally do NOT use the entire yeast cake.

+1. Unless your second beer is of a very high gravity, about 20-25% of the cake is plenty for an ale (40-50% for a lager) and allows for the yeast to go through their normal phases. Harvest and rinse the rest for later batches. All you need is a sanitized plastic spoon and some canning jars. Having a bunch of jars with boiled/chilled water on hand makes it pretty easy.

Be ready with a blow-off tube since the second ferment may be a bit enthusiastic.

One of these days, I'll get inspired to do a really big beer like a barleywine or an imperial something or other. Instead of doing a series of large starters on the stirplate, I'll start by making a 1.045-ish beer and then use the whole yeast cake for the high-gravity batch. That's like making a 5-gallon starter that you get to drink.

 

[Cathedral]

Is there any sort of time "limit" on how long the original beer was in primary before you shouldn't use it for another batch?

For example, if I've had my IIPA in primary for three weeks, would the yeast possibly be too dormant (or dead) to re-ferment another batch? Five weeks? Longer?

And for the people who just pour new beer back onto the whole old cake, do you not sanitize the carboy? Or take the cake out, sanitize the bottle, then put the cake back in?

 

[Yooper]

Is there any sort of time "limit" on how long the original beer was in primary before you shouldn't use it for another batch?

For example, if I've had my IIPA in primary for three weeks, would the yeast possibly be too dormant (or dead) to re-ferment another batch? Five weeks? Longer?

And for the people who just pour new beer back onto the whole old cake, do you not sanitize the carboy? Or take the cake out, sanitize the bottle, then put the cake back in?

I don't think it's so much a time limit as much as an ABV/stressed limit. I would NOT use a yeast cake that previously held an IIPA. That's got to be some stressed yeast, with some alcohol poisoning.

I'd definitely keep fresh yeast from a smaller OG beer (say, 1.055 or less) and consider something higher maybe. But I wouldn't reuse a yeast cake from a bigger beer as a rule.

 

[Jints07]

Thanks Yooper and BigFloyd, this info is great stuff!

{scurries off to write more notes}

 

[tgmartin000]

I just did it for the first time 1.055 Munich helles to a 1.074 maibock. Since these beers used a total of one oz of hops for two five gallon batches I figure there's going to be Minimal hop debris.

But if you're dry hopping in the primary, or have lots of gunk in there, I'd think twice. Or wash the yeast. It gets better after a couple generations.

 

[el_horno]

And for the people who just pour new beer back onto the whole old cake, do you not sanitize the carboy? Or take the cake out, sanitize the bottle, then put the cake back in?

No need to sanitize, you did that prior to pitching initially, its been air tight ever since, so assuming your sanitizing practices are sound, there is little chance for infection.

That being said I do wash my yeast when I plan to store it for future use. Ive only dumped onto the yeast cake once after racking my flanders red and brewing a brown sour the same day.

 

[Cathedral]

Thanks, everyone, for the information.