4

I use a 750 ml bottle, sanitised aluminium foil and a rubber band. Keep aerated by stirring it gently, occasionally during the first 12h; I stir every 6th hour or so. After 18-48h I use it or refrigerate it for later use. I use White Labs instructions for reference, no matter the brand of yeast I buy. Cheers!


4

Smack packs contain yeast nutrients, and sugars nothing magical. Its just a mini starter in a bag for proofing yeast for direct pitching. Don't need it at all If doing your own starter. If you do all grain your wort has all the nutrients it needs. Sounds like your 1st stage went fine. I would just step up as normal. At the risk of infection just throw the ...


4

Yes you can. I've fermented apple wine this way on a DIY stirplate, 1 inch magnet, and a vintage arrowhead carboy (flat bottom). It wasn't powerful enough to make a deep cone for oxygenating which actually worked nice as I just wanted to deny the yeast the option to flocculate. My stirplate uses an old SCSI external 5.25 tape drive, so it's platform is ...


3

I haven't noticed any difference in the performance of my home-built stir plate between water and wort/yeast with one exception. I often make two-stage starters and refrigerate the flask between stages. then decant most of the old wort and add new wort. The resultant yeast slurry is very thick, and the stir plate can't turn the bar through the thick slurry. ...


2

'Is such a high growth rate (assuming that everything is optimal) actually possible[...]?' It sure is. Yeast will pretty much grow indefinitely as long as there are no nutrient limitations or inhibitory levels of ethanol. The major limiting nutrients are: Fermentable sugar Nitrogen (amino acids, basically) Oxygen (more accurately, the lipids synthesized in ...


2

You could build a stir plate - you probably already have most the stuff laying around. Step 1: Gather a computer fan, power supply, stir magnet, and neodymium magnets and 2 L mason jars. Step 2: Glue 2 neodymium magnets to the computer fan facing upward, with one + side up, the other - side up. The diameter should be the length of your stir magnet. Step 3:...


2

A stir plate does two things. Both can be done manually by swirling your vessel. Provides the yeast a good amount of oxygen. Reduces yeast lost, from lifting out with krausen and drying on the sides. Put your starter in a common place like in the kitchen and swirl of whenever you walk by. Erlenmeyer flasks are unique in that they are made of Pyrex and ...


1

I Use various size canning jars, I have the, from .5L up to Half Gallon. I only fill them up Half way to 3/4 full. And when making the starter, I leave the lid partially screwed on. Then during the process, every time i walk by Open up the jar swirl Then I spend about 10 seconds shaking it with the lid on Tight. then crack it.


1

I don't think you need something so heavy duty for the batch sizes you're talking about. The "standard" homebrew stir plates are generally built with hard-drive magnets and computer case fans. These can readily move wort in flasks from 2-4L, and probably up to 6L, as well, with just a bigger stir-bar. Looking at yeast-starter calculators, for 100L of low-...


Only top voted, non community-wiki answers of a minimum length are eligible