New stir plate

I just completed my stir plate and want to start making some yeast starters but I am wondering if my vortex is overkill or if I will be fine. I tried a 5v, and 12v power supply and neither would keep the stir bar spinning properly so I am using a 9v at the moment. I have a speed setting but it doesn't go down low enough so I am left with a fast spinning stir bar. I may end up having to find a 7v charger or something but I would like some opinions first.

Here is the link to my video [ame]http://www.facebook.com/video/video.php?v=219051428140567&comments[/ame]

If you put a heat sink on a LM317 you can control voltage and that will give you full range of speeds but look at DIY forums for that. From a yeast perspective I don't see a problem, Yeast spin, get air, stay in suspension all is good. The only reason you might need speed control is if your flask is getting full and you have an active starter that wants to boil over. That is only only time I dial my done from full speed!

Clem

Just looked it up sounds like something I could definitely do thanks for the suggestion. I will probably get around to it eventually but I think I will try it this week how it is. I am already thinking I should get a larger beaker so I can make larger batches of yeast. If it starts to get too full I can always use a growler I will just have to find a way to fit it on their securely.

I was gift two one liter flasks and I have been putting up with them and the krausen that escapes them. I can't do much more than 750ml of starter without the yeasties making a run for it! I'm just glad I made the top of my stir plate out of plastic.

Another consideration when you are using any form of speed control is insulation from the starter. You don't want the heat from the stir plate effecting the temp of your starter. Run it up with water over night and note temp before and after to check.

Clem

Thanks for the info I didn't even think about it heating up my starter but its something I will watch. I was planning on cutting some vents in the box for heat to escape hopefully that is enough otherwise I might wire up another fan in their.