I've got a stir-plate, now what?

[Dan_K]

Let's say I'm brewing on Saturday and pitching yeast at 12:00 noon.

What does my starter situation look like given this timeframe?

I have a 2L flask so I'd either be doing 1L or 2L starters depending on what beer I'm making. But when should I be starting the starter? I'd probably pitch the whole thing without decanting/cold crash.

Also I think I need a "keeper magnet" for my stir-bar, any idea what kind of magnet I need for this? Tried a fridge magnet, it didn't work.

 

[NTexBrewer]

http://www.whitelabs.com/resources/homebrew-starter-tips

Here is a good read.

Usually you spin the yeast for 24hrs. You will see the starter get creamy colored and notice a lack of bubbles along the edge of the flask. Then cold crash so you can decant to pitch or step up the starter.

I usually like to cold crash the starter for 48 hours to make sure most of the yeast settles out. Highly floculant yeast will settle out faster.

So if I'm brewing on Saturday, I'll make the starter on Wednesday. Thursday, put the starter in the fridge. On Saturday, decant and let it warm up to room temperature.

I have a small aquarium cleaning magnet that works perfect for catching the stir bar. I would think that any strong magnet would work.

 

[Dan_K]

Very helpful thank you!
Also something I picked up from the White Labs recommendation, was using 1/2 cup of DME per quart of water, seems pretty straightforward (was weighing out the DME before).

One thing that didn't make sense- if a stir plate is so much better at growing yeast, why are the recommendations the same for stir plate or no?
(probably for simplicity sake)

Also, is aerating your wort really necessary if you have a stir plate? I am thinking you could just... turn on your stir plate for 30 sec before you pitch the yeast.

 

[mongoose33]

I use a small disc magnet to hold my stir-bar. You can buy them at a home store, they may be labeled neodymium, or a rare-earth magnet. THey aren't all that cheap, but that's why they're strong.

I have a bunch of these stuck to a metal cabinet of drawers. The stir bar gets attached to them when not in use, and it comes off as well as one of the magnets when I need to use it.

I do something similar to NTexBrewer does, though I typically only cold crash it for 24 hours and then decant. Going to have to think about doing it longer so I don't lost the less-flocculent yeast--though if you pitch the entire thing, that won't matter.

Seems to me there was a Brulosophy exbeeriment comparing decanted vs. non-decanted starters.

*****************

BTW: this is one thing I tend to forget, and that's removing and decanting the starter well in advance of when I need it. The yeast needs time to warm up to pitch temp. It will warm much faster, of course, if you decant off most of the liquid. As to time, if you're planning on pitching at noon, I'd have it starting to warm by 8am if you don't decant, maybe a little later if you do. Depends of course on ambient, but don't pull it out of the refrigerator at 11:00am and presume it'll warm up enough by noon--it won't.

In the meantime, you could test this very easily--put a flask w/ a liter of water in the fridge, let it cool down overnight, then pull it out and put in a thermometer and see just how long it takes to warm up to ambient.

 

[NTexBrewer]

Very helpful thank you!
Also something I picked up from the White Labs recommendation, was using 1/2 cup of DME per quart of water, seems pretty straightforward (was weighing out the DME before).

One thing that didn't make sense- if a stir plate is so much better at growing yeast, why are the recommendations the same for stir plate or no?
(probably for simplicity sake)

Also, is aerating your wort really necessary if you have a stir plate? I am thinking you could just... turn on your stir plate for 30 sec before you pitch the yeast.

I'm guessing they are just saying that for simplicity. Stir plate should always be better since it keeps the yeast in suspension and oxygenates the starter.

I usually brew 2.5 to 3 gallon batches so that is why I always decant.

 

[Dan_K]

How vigorously do I want to be stirring it? Barely spinning or yeast tornado?

 

[unviewtiful]

How vigorously do I want to be stirring it? Barely spinning or yeast tornado?

At a minimum, you'll want to have a dimple at the top of your starter. If your vortex is too aggressive, you'll throw the stir bar. I usually set mine for a vortex that occasionally touches the bottom (you'll hear a bit of a slurping sound) at the beginning. As the yeast propagate, the starter becomes slightly more viscous, which reduces the depth of vortex.

 

[TorMag]

How vigorously do I want to be stirring it? Barely spinning or yeast tornado?

I've got a DIY stir plate aka computer fan. Mine has a level where it is too fast and throws the magnet. So I keep it just under that speed, but I do get a nice whirlpool.

 

[tjm02c]

Anyone have a recommendation on where to find a cheap, but solid stir plate?

 

[hezagenius]

Anyone have a recommendation on where to find a cheap, but solid stir plate?

What do you consider cheap?

This is what I use
https://www.amazon.com/gp/product/B008F0CTBA/?tag=skimlinks_replacement-20

$47 won't break the bank and I don't have to build it. I don't recall if it came with a bar. I bought this one:
https://www.amazon.com/gp/product/B008F0CTBA/?tag=skimlinks_replacement-20

 

[tjm02c]

Yeah from my fairly limited research I was seeing around $50 as cheap. Just wasn't sure of the quality. Thanks

 

[beergolf]

I have had thi sone for years and have made a couple of hundred starters. Works great.

http://stirstarters.com/

 

[bleme]

I've gone through several desktop computers over the years and I always pull the hard drive before I get rid of it. Every hard drive has 2 very powerful magnets in it. They are great for holding the bar in place.

 

[Dan_K]

Anyone have a recommendation on where to find a cheap, but solid stir plate?

This is the one I purchased:
It came with 2 stir bars. I have no real complaints so far, other than that the top surface is kind of slick. It needs a thin rubbery coating or something. I'll probably scrub it with a brillo pad. It's also a bit small so large flasks will overlap the edges.

https://www.amazon.com/dp/B01M3RUGQY/?tag=skimlinks_replacement-20

 

[JAReeves]

"Alakazam, alamazzoooo!"

So, having resurrected a necro-thread, I would like to ask a question related to stir plates and stir bars.

I received a DIY stir plate that throws my standard 1" (straight, no middle raised section) stir bar at the lowest speed.

While I like the links to the various stir plates mentioned in this thread, I am wondering if there is a way I can continue to use this stir plate. It's kind of cool and geeky, the DIY'er made it out of an Xbox 360. I don't know, I didn't ask.

Anyway, since it's throwing the smallest of stir bars, how do I solve this issue?

A. Larger stir bar?
B. Lower power potentiometer?
C. Something I didn't think of because, "Dammit Jim, I'm a theologian, not an electrical engineer!"

Thanks in advance,

Reevesie

 

[Jim R]

You need a stir plate with a smaller motor. This one for $45 works great and made be decide to bag the DIY option.

https://www.homebrewing.org/The-Stirstarter-Yeast-Stir-Plate-_p_1306.html