Pressure Fermenting

Discussion in 'General Brewing Discussions' started by myben, Nov 28, 2018.

  1. myben

    myben New Member

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    Anyone had any experience with fermenting under pressure. Info seems to suggest grain to glass time is reduced by a bit and the ability to ferment at higher temps,Not much of an issue with ales but because I don't have the patience to brew lagers it might be a solution. Be interesting to hear if anyone has tried this.
     
  2. J A

    J A Well-Known Member

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    I'm just getting into using my Unitank that has the capability of holding pressure at any point in the fermentation. So far I've only tried "capping" or closing the tank to hold pressure from the last few points of fermentation in order to carb the beer. I suppose I could try spunding for a lager, but I don't find that fermentation takes particularly long with the right yeast and the right temperature. For the most part I do lagers at temps in the high 50s and ramp up to diacetyl rest relatively quickly so that fermentation can be done in a week or less. Then another week for crashing and kegging. The last S-23 "speed" lager I did for a party was packaged on day 11, extremely drinkable at 3 weeks and really clear and clean at 4 weeks. Even my last couple of lagers where I held at 52 for 10 days before ramping slowly were fully attenuated and D-rested in about 2 weeks.
     
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  3. Vesparados

    Vesparados Well-Known Member

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    Fermenting under pressure is intriguing to me as well. I look forward to more reports on the topic
     
  4. KC

    KC Active Member

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    Closed fermentations are correlated with high DMS so I'd be wary of that
     
  5. The Beerery

    The Beerery Active Member

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    My professional opinon is that of... Never ferment under pressure unless you have too. Hydrostatic pressure and yeast cause all sorts of funk. If you ask any professional brewer if there was an option for fermenting under pressure or no pressure. 99% would beg for the latter. Fermenting under pressure introduces a large number of un-necessary variables, that most homebrewers don't need (or know how) to combat.
     
  6. Nosybear

    Nosybear Well-Known Member

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    I'm wondering what people are trying to achieve by fermenting under pressure. Pressure is inevitable in tall conical fermentors but the yeast is constantly moving from the high pressure environment at the bottom to the low pressure environment at the top, sure. But why would we want to do that at homebrew scale for any reason other than carbonation?
     
  7. Hawkbox

    Hawkbox Well-Known Member

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    I think it's like a lot of other things we do in home brewing, someone got it in their head it did "something" and now it's gospel in certain circles.
     
  8. Hogarthe

    Hogarthe Well-Known Member

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    In the old days they didn't have co2 tanks so they fermented under pressure to carbonate. Someone heard this and decided since it was traditional they needed to do it too.
    First time I heard of it was one of the yeast labs has a high pressure lager strain. Supposed to ferment faster and at higher temp. So if you can do pressure but not temp control, or are pressed for time it's an option.... Not needed for homebrew. Big companies have time limits for scheduling their orders. homebrewers dont so I see no no point for it unless you are doing It commercially.
     
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  9. The Beerery

    The Beerery Active Member

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    You don't need to ferment under pressure, you just move the beer to its final resting place about 4 points above FG. This is spunding, and its how basically all german lagers are brewed.
     
  10. J A

    J A Well-Known Member

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    That's what makes sense. The notion of spunding from pitch seems unnecessary. Capping or holding pressure at the point that the proper volumes of CO2 will be held in suspension and "pre"-carbonate the beer makes perfect sense. The quality of the carbonation is much closer bottle conditioned and it's ready to serve virtually right out of the fermenter. So far I've only got one batch done this way but I'll definitely use this method for everything I can.
     
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  11. Craigerrr

    Craigerrr Well-Known Member

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    I have a friend that ferments under pressure, he is all about getting into the glass as quickly as possible.
    His beers are quite good, come out tasting nice and clean.
     
  12. The Beerery

    The Beerery Active Member

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    You don't need to ferment under pressure to make that happen though.. Just spund. My ales are ready to drink 36hrs, and lagers 7 days from brewday if I wanted too... Proper pitch rates, cold fermentations even, no corners cut or gimmicks. But do you REALLY need beer that fast..
     
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  13. Nosybear

    Nosybear Well-Known Member

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    My answer would be to each their own.... I don't keg, for example, so refermentation is the only way I can get carbonation. Similar processes, except one uses the sugars in the wort and the other adds them back to feed the yeast. Roughly the same result is what I'd expect, except for the speed factor. I don't like drinking green beer so longer is better, for me. As we agreed last night at the wine pairing dinner, you make wine to your own taste. Same is true with beer.
     
  14. HighVoltageMan!

    HighVoltageMan! Well-Known Member

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    I haven’t heard that before, but it could very well be true. I often wonder how sulfur reduction is achieved with pressurized fermentation, natural degassing is effective for home brewers. As Nosy noted, conical fermenters develope higher hydraulic pressures at the bottom of the vessel and is said to suppress ester production. Great for German lagers, not very good for Belgians and fruity English beers. I think the yeast characteristics will change under pressure. Some for the better, some for the worse.
     
  15. KC

    KC Active Member

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  16. Ozarks Mountain Brew

    Staff Member

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    one thing that really gets me and we all do it to a point is the miscommunication from commercial brewery practices bleeding into home brewing, there are many differences in the size of batches and how things are done, they don't always cross, so in a sense a closed transfer or under pressure and fermenting the same way in a keg won’t have the same effect as a 30 foot conical so as long as the pressure comes from the yeast and vented to a certain level it should be fine as long as the level is low but just letting the yeast pressurize the keg until they stop eating would not be a good thing, it’s going to stress the yeast and cause off flavors
     
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