I have done some research and had some conflicting answers. Anyways, I made a yeast starter in a half a gallon glass growler this past Friday evening. So as of now, it's almost been 30 hours. I used about half a pound of muntons wheat dme and about 50oz of water. At first I used an airlock, until after about 12 hours I didn't see much bubbling activity (very little after swirling it) so I was worried about the lack of oxygen. So I replaced the airlock with a piece of sanitized foil. I do not have a stir plate, and due to my work schedule there's 12+ hour increments I can't swirl the starter at all. Anyways, this morning (24 hours into it) there's a cake-like thin layer of sediment at the bottom, and very little krausan at top. My questions are, how do I know if that sediment at the bottom is yeast, or trub? The sediment is thick, but looks like little peices of wax floating around. Not really powdery looking, more chunky. My brew day is tomorrow late-morning, should I cold crash it tonight? Will my inability to always stir it/changing out the airlock to foil hurt anything? I guess I'm kind of confused if my starter is ready or not. Thanks
Your starter should be done by now. My personal practice is to permit the starter to go for 18-24 hours. I personally choose to pitch the entire starter while it is at high krausen. Some folks like to cold crash the starter and decant the liquid. Your choice whether to cold crash/decant or pitch the whole starter. Cheers! P.S. From what you described it sure sounds like you have yeast on the bottom of your starter.
I wait until the starter appears to be done fermenting. Sometimes that is 24 hours, sometimes longer. Depends on the age/health of the yeast and the volume of the starter. I also always decant and find that the time it takes for yeast to drop it depends mostly on how well the strain flocculates. Also how cold the temperature is. On average I spend about four days on these two processes. I'm usually not in a rush, so if I give myself a week, no harm there.
Does not having a stir plate lengthen the amount of time I have before I see active fermentation? I'm just making sure my timeframe is ok: 35 hours of room temp, 12 hours of cold crash.
I forgot to mention that, yes, not having a stirplate will lengthen the fermentation time of the starter
I do not have a stirplate and my yeast starters are ready to be pitched at around 18 hours. I do periodically shake them (but not over that entire 18 hours; probably shake for about 8 hours of that 18). Cheers!
