Efter att ha passivt följt en diskussion på shbf.se om det bästa sättet att torrhumla sin öl så hitta jag i ett av inläggen en länk till reddit (som i sin tur länkar till en 3-4 år gammal post på HomeBrewTalk) om sekundärens vara eller icke vara.
John: And unfortunately I’m an perpetuator of the myth at HowtoBrew.com. The 1st edition talks about the benefits of transferring the beer off the yeast.
Jamil: Well that was the popular way of doing things. But that was what, the 1st edition? Stop getting the thing off the internet. Buy yourself the 3rd addition copy and get the updated information.
John: As we’ve gotten more educated on how much good healthy yeast you need for optimum fermentation the advice that we used to give 20 years ago has changed. 10 years ago, 20 years ago, homebrewers were using with a single packet of dry yeast that was taped to the top of the can. There weren’t as many liquid yeast cultures available.
Jamil: People didn’t make starters either.
John: Right. So the whole health and vitality of yeast was different back then compared to know. Back then it made sense. You had weaker yeast that had finished fermentation that were more susceptible to autolysis and breaking down. Now that is not the case. The bar of homebrewing has risen to where we are able to make beer that has the same robustness as professional beer. We’ve gotten our techniques and understanding of what makes a good fermentation up to that level, so you don’t need to transfer the beer off the yeast to avoid autolysis like we used to recommend.
Jamil: Unless you are going to do long term at warm temperatures, but even then we are talking over a month. I thought about this as well and I think one of the reasons autolysis….and the fact that people were using weak yeast in inappropriate amounts and the transfer would add some oxygen to it which would help attenuate a few more points. I think that was part of the deal why transferring was considered appropriate years ago.
John: But these days we don’t recommend secondary transfer. Leave it in the primary, you know, a month. Today’s fermentations are typically healthy enough that you are not going to get autolysis flavors or off-flavors from leaving the beer on the yeast for an extended period of time.
Jamil: And if you are using healthy yeast and the appropriate amount and the thing is… homebrew style fermentors..if you are using a carboy or plastic bucket which have that broad base when the yeast flocculate out they lay in a nice thin layer. When you’re dealing with large, tall…one of the things you know people go “Well the commercial brewers they remove the yeast because it is gonna break down, die, and make the beer bad. We should be doing the same thing.” That’s where alot of this comes from. But the commerical brewers are working with 100 bbl fermenters that are very tall and put a lot of pressure on the yeast. The yeast are jammed into this little cone in the bottom and they are stacked very deep and there is a lot of heat buildup. The core of that yeast mass can be several degrees C higher than the rest of that yeast mass and it can actually cook the yeast and cause them to die faster and cause those problems with flavor and within a couple of days the viability of that yeast which the commercial brewers are going to reuse is going to drop 25%, 50% over a couple of days so they need to get that yeast out of there. You don’t have that restriction as a homebrewer. You’ve got these broad fermenter bases that allow the yeast to be distributed evently. It’s an advantage for cleaning up the beer. You have the advantage that the yeast don’t break down as fast. You don’t have as high a head pressure. There are a lot of advantages.
Överföringen av ölet till sekundären var för att förhindra autolys, som kommer av jäst som dör. Jästen har förbättras mycket de senaste 10-20 åren och det är numera ingen risk att lämna sin öl stående på jästkakan i en månad. Jästen är inte bara bättre nuförtiden, vi har större kunskap om hur mycket jäst som behövs till vår stamvört.
Kommersiella bryggare för över sin öl på grund av den värma och tryck som jästen utsätts för i de koniska jästankar de använder som gör att jästen dör. En hembryggares jäskärl orsakar inte denna skada på jästen och behöver därför inte föras över till sekundären.
Detta kommer i alla fall leda till att jag kommer använda mig mindre av sekundären än vad jag gör idag. Detta är ju också en fördel då man slipper flytta ölen en gång extra med allt vad det betyder med att det kommer i kontakt med syre och risken att det infekteras.