There's this scummy film that forms on top of wort during biol. Should you stir that in or is it best to leave it alone. Sometimes I'll fish it out with a strainer right at the beginning of the boil just for something to do, but I don't think it matters. Generally it just dries to the sides of the kettle. Once you add hops, I'll maybe stir it a little since it tends to capture some hop material.
There are skimmers and non-skimmers. It's a personal choice. It will not hurt your beer to leave it in. That being said I skim the scum because it's easy, I don't like the looks of it and I don't want it in my beer. By stirring the wort really well before pitching the yeast, you are giving the yeast a good oxygen supply with which to kick off the fermentation. The sediment will settle out in the bottle though, it may take longer with the ones that have more in them, but it will still get there.
In fact, primary fermentation should never be airtight because you run the risk of blowing the top off of your fermenter or breaking it completely. As carbon dioxide is created during the fermentation process, an incredible amount of pressure can build up over time. Fermentation is finished when it ceases to off gas. The airlock is still and has reached equilibrium.
If you brew in glass, look at the beer, the yeast ceases swimming and flocculates settles on the bottom. It is perfectly fine to open the lid of your fermenter to check the process or take a gravity reading provided that you take the proper precautions to sanitize all equipment used, minimize the amount of oxygen added to your wort, and re-seal the fermentation bucket fairly quickly to avoid contamination.
Many brewers simply follow the beer recipe or instructions on the malt kit and leave their wort to ferment for around a week to ten days.
The dense foam had not formed on top, the fermenter did not turn a creamy opaqueness that indicates yeast multiplication and healthy fermentation.
Within 12 hours at the most, the yeast should have multiplied to begin its sugar to ethanol conversion. It does its work slowly, exhibiting a milder, gentler krausen. Lagers may take 15 — 28 days for full fermentation , requiring a well-found patience. Off flavors include index-card, musty, used booky : sounds crazy, but this is what it brings! Another violent result of oxidation is the formation of Acetaldehyde. Acetaldehyde not only forms due to under-pitching and O2 exposure, it will also reconvert your alcohol back into itself, a rancid and villainous contaminating compound.
After cold break solids falling out during cooling and cool-down, stir away! Remembering that all post-boil contact must be sanitary, if stir you must do it in a manner in which the lid keeps the fermenter mostly covered.
The stirring introduces O 2 to the wort and mixes the yeast well before its brief pre-fermentation rest. Consider this a preemptive stir allowing the greatest possible success for respiration and cell multiplication. See my article for best handling of pre-pitch yeast: article on hydrating yeast.
Rest it on the floor with a towel underneath for cushion. Pitch the yeast on brew day, fermentation picks up, there is healthy bubbling , swimming, and a krausen on the beer, even if not the most vigorous.
Then, crickets …the foam dies down, a heavy slurry rests on the bottom. Taking a hydrometer reading, the gravity reads 1.
0コメント