Krausening Techniques?

[jasonclick]

I listened to the Beer and Brewing podcast a few days ago and they interviewed a brewer that makes German Pilsners the traditional way. Anyways he talked about carbing up the beer through krausening. I know what krausening is but was wondering about the logistics in doing so.

I have a small electric BIAB system that I typically make 4 gallon batches. I ferment in corny kegs. I could make a little more so here are my thoughts...
Make a 4.5 gallon and seperate 1/2 gallon and freeze it. Once the main batch is at terminal gravity, transfer it to the serving keg. Boil and cool the reserved 1/2 gallon wort and add a little yeast from the fermenter to the the half gallon. Once that's at high krausen, add to the serving keg along with a spunding valve set to 15 PSI.

Does that sound like a good plan? Any different way it should be done?

 

[McKnuckle]

I have done nearly what you describe with my last two batches, one of them a Czech pils and the other an English brown ale. Technically I did not krausen, but I reserved and added speise. It's similar:

I make 2.5 gallon batches. I reserved about one pint of hot wort in a Mason jar just before chilling, and placed it in my 39ºF keezer, which seals it right up. I did not bother to literally freeze the wort, or to boil and cool it later. It goes into the jar at 200+ºF, so it's sterile. There's nothing that can really happen to it, and the additional freeze/boil/chill cycle seems like more of a risk plus it's a PITA.

Anyway, I fermented the rest of the batch to terminal gravity, then racked into a keg and added the reserved wort (speise) and a small dollop of yeast. I then pressurized the keg lid to seal it, and left it to carbonate. I used a spunding valve to monitor pressure. When pressure was no longer increasing, I put the keg into my keezer to further condition before drinking.

BTW, you need to achieve PSI that allows the right amount of CO2 volumes based on the fermentation temperature. So it's not going to be as simple as just 15 psi. Refer to a carbonation chart.

Here's a gyle (speise) calculator. 1/2 gallon is too much wort to prime 4.5 gallons, but you can see for yourself how it estimates and plan accordingly.

So far the two beers I've done this with... taste like beer. I enjoyed the process and it feels traditional and natural, plus the carbonation is deeper and finer. It's not earth shattering, but I'll keep doing it, as it also saves CO2.

 

[jasonclick]

I have done nearly what you describe with my last two batches, one of them a Czech pils and the other an English brown ale. Technically I did not krausen, but I reserved and added speise. It's similar:

I make 2.5 gallon batches. I reserved about one pint of hot wort in a Mason jar just before chilling, and placed it in my 39ºF keezer, which seals it right up. I did not bother to literally freeze the wort, or to boil and cool it later. It goes into the jar at 200+ºF, so it's sterile. There's nothing that can really happen to it, and the additional freeze/boil/chill cycle seems like more of a risk plus it's a PITA.

Anyway, I fermented the rest of the batch to terminal gravity, then racked into a keg and added the reserved wort (speise) and a small dollop of yeast. I then pressurized the keg lid to seal it, and left it to carbonate. I used a spunding valve to monitor pressure. When pressure was no longer increasing, I put the keg into my keezer to further condition before drinking.

BTW, you need to achieve PSI that allows the right amount of CO2 volumes based on the fermentation temperature. So it's not going to be as simple as just 15 psi. Refer to a carbonation chart.

Here's a gyle (speise) calculator. 1/2 gallon is too much wort to prime 4.5 gallons, but you can see for yourself how it estimates and plan accordingly.

So far the two beers I've done this with... taste like beer. I enjoyed the process and it feels traditional and natural, plus the carbonation is deeper and finer. It's not earth shattering, but I'll keep doing it, as it also saves CO2.

Thanks. I was wondering about the amount of krausen. Since it's got a spunding valve, any excess CO2 will blow off. I'll check out the calculator.

 

[Brooothru]

I have done nearly what you describe with my last two batches, one of them a Czech pils and the other an English brown ale. Technically I did not krausen, but I reserved and added speise. It's similar:

I make 2.5 gallon batches. I reserved about one pint of hot wort in a Mason jar just before chilling, and placed it in my 39ºF keezer, which seals it right up. I did not bother to literally freeze the wort, or to boil and cool it later. It goes into the jar at 200+ºF, so it's sterile. There's nothing that can really happen to it, and the additional freeze/boil/chill cycle seems like more of a risk plus it's a PITA.

Anyway, I fermented the rest of the batch to terminal gravity, then racked into a keg and added the reserved wort (speise) and a small dollop of yeast. I then pressurized the keg lid to seal it, and left it to carbonate. I used a spunding valve to monitor pressure. When pressure was no longer increasing, I put the keg into my keezer to further condition before drinking.

BTW, you need to achieve PSI that allows the right amount of CO2 volumes based on the fermentation temperature. So it's not going to be as simple as just 15 psi. Refer to a carbonation chart.

Here's a gyle (speise) calculator. 1/2 gallon is too much wort to prime 4.5 gallons, but you can see for yourself how it estimates and plan accordingly.

So far the two beers I've done this with... taste like beer. I enjoyed the process and it feels traditional and natural, plus the carbonation is deeper and finer. It's not earth shattering, but I'll keep doing it, as it also saves CO2.

This is very timely for me. I just started fermentation on a Pre-Prohibition style lager. I've done the recipe quite a few times and have won several awards in competitions with it, but I've been thinking about adding a new twist. Like @jasonclick I've been aware of Krausening but never appreciated the actual difference between that and speise, and never got around to actually trying the process(es). Time to give it a try.

Looking at the calculator, I figured I'd need about 1.3 quarts. Trouble is, the wort's already in the fermenter and has started to bubble. It's only been about 35~40 hours at 50F, so it's nowhere near high krausen. I'm thinking I could decant 2 quarts into a 1.5 gallon mini-keg and put it in my 38F kegerator in order to slow down the fermentation well below the fermentation rate of the original batch. Then when it's time to transfer from the fermenter to a keg, I'll combine the "green" beer with the reserved early ferment beer and bring the combined keg up to D-rest temperature under a 15 psi spunding valve.

If it works, the benefits are that the wort and yeast are the same as the original (since they are the original). I don't know what I'd call the process since it's not truly krausening and it's not technically speise. I dunno, maybe "speisening"? The process would be:

1). Separate a sample in early fermentation. Store at low temperature to slow the fermentation.
2). Ferment the bulk of the original wort at 50F. At or near FG, soft crash to drop trub and "tired" yeast.
3). Rack/pressure transfer original batch and reserved early ferment wort to keg. Attach 15 psi spunding valve and allow the keg to free-rise to 68~72F for carbonation and D-rest/clean-up.
4). Cold crash and lager.

Think it would work? The original wort was 1.045 and has probably dropped at least ten points by now. It would probably drop another 10 at 38F while the fermenter finished at a predicted 1.009. Some of the "speisening" yeast would likely start to go dormant but should revive with the free-rise to 68~70F and hopefully be enough to get me up to 2.6 volumes CO2.

For the last year or so I've gotten away from forced carbonation and have just been capping the fermenter at 5 points before predicted final gravity (FFT) to achieve 15 psig and it has worked out quite nicely. This method would (should) give nearly the same result, but with more trub/yeast in the serving keg, but also with less oxygen (i.e., NONE). It would also free up my Unitank a lot sooner for the next batch. Plus, I just had to cough up $34 for another 10# bottle of CO2, which is about the same amount I pay for grains and hops for a 5 gallon batch. This would be like....FREE BEER!

 

[JAReeves]

I appreciate this thread and the knowledge being shared very much, as I am planning my first lager this winter. Even though I have a cooling system for my fermenters, I figure I won't have to buy as much ice to keep it cool through fermentation with a cold garage. Anyway, I am hoping to use this method of adding some wort back in with a fresh dollop of yeast to get the carbonation level I want.

I have two questions, and I apologize in advance, as I am not trying to hijack the thread.

1: I want to dry hop the lager (Tipopils-style), so would I dry hop before doing a speise or put them in at the same time?

2: I want to ferment two at the same time, but I only have enough yeast at the moment to start one. Once the first fermentation is rolling, can I pour off 1-2 cups of rapidly fermenting wort and use it as a starter for the next batch that I am hoping to start 1-3 days after the first batch?

Peace,

Reevesie

 

[ba-brewer]

I appreciate this thread and the knowledge being shared very much, as I am planning my first lager this winter. Even though I have a cooling system for my fermenters, I figure I won't have to buy as much ice to keep it cool through fermentation with a cold garage. Anyway, I am hoping to use this method of adding some wort back in with a fresh dollop of yeast to get the carbonation level I want.

I have two questions, and I apologize in advance, as I am not trying to hijack the thread.

1: I want to dry hop the lager (Tipopils-style), so would I dry hop before doing a speise or put them in at the same time?

2: I want to ferment two at the same time, but I only have enough yeast at the moment to start one. Once the first fermentation is rolling, can I pour off 1-2 cups of rapidly fermenting wort and use it as a starter for the next batch that I am hoping to start 1-3 days after the first batch?

Peace,

Reevesie

I would do the dry hop first then add the speise after removing the hops.

If you go 3 days I would move the first batch to the second fermentor and use the cake in the first fermentor for the next batch. A cup or two does not seem like enough but I think if you added that to some fresh wort and put it on a stir plate you could build that up to something usable in a few hours.

If the beers were the same kind then maybe use a larger amount of the first batch and back fill the first ferment with fresh wort.