Are stir plates worth it?

[MaxStout]

Just for grins and giggles, I set up a poll on this.

 

[D-Train]

Two biggest advantages of a stir plate for me...

A 25% reduction in extract required by my calculations. Extract isn't cheap.

More importantly, most beers I make would require a stepped starter in a 2L flask without a stir plate. That's time saved.

Ok third reason. I've started saving a portion of most starters to cut costs on each batch. Having the higher yield of a stir plate makes this much easier to do.

 

[EarlyAmateurZymurgist]

2. No, I don't think so. Stir plate is constantly introducing oxygen and knocking co2 out of solution and maximizing yeast contact with the wort. You are not going to achieve this with swirling every once in a while. It is not a function of time

Actually, the O2 part of your assertion is false. While it is true that a stir plate helps to force CO2 out of solution, CO2 is heavier than air. The culture is also under positive pressure, which greatly reduces, if not outright prevents air infiltration.

 

[billybryson54]

I'm in the boat that says "yes, they are worth it" but I also built both of mine out of some stuff I had laying around. Cost me probably 20 bucks for both. I like to be able to have my starter in my fermentation fridge which is in my garage, flip the switch, and just walk away for a few days

 

[schematix]

Definitely worth it. If anything you can make smaller starters, which saves money on extract.

I take my stirring seriously: https://www.homebrewtalk.com/f163/quad-stir-plate-507040/

 

[RmikeVT]

Actually, the O2 part of your assertion is false. While it is true that a stir plate helps to force CO2 out of solution, CO2 is heavier than air. The culture is also under positive pressure, which greatly reduces, if not outright prevents air infiltration.

I guess I should have been more specific, "constantly introducing oxygen throughout the lag/growth phase."

 

[BadWolfBrewing]

Since I built my starter, my love has really improved and my dog learned to poo in the toilet.

There's so much conflicting info out there. Many take Mr Malty's numbers as written in stone, myself included. His number show a giant increase in yield due to a stir plate. Here's what I got for a 1.1 OG, 5 gallon ale. Looking at required starter volume:

Simple Starter: 6.55 L
Simple Starter with O2 at start: 4.91 L
Starter with Shaking: 3.78 L
Starter with continuous aeration: 3.28 L
Starter with stir plate: 2.46 L

I have no idea if their numbers are correct. I'm not willing to do a controlled fermentation experiment either. I work in a research field, and I know first hand that you can chase your tail for years trying to validate or disprove somebody else's experiments and ideas. There's way too many factors here, and for us no means to quantify the results accurately aside from finishing gravity.

So, if a stir plate means I get away with a much smaller starter, its worth it. Less DME, dont need a larger flask. Also, it was fun to build. Like many, I just used stuff I had sitting around. Nowadays though, you can get a voltage controller cooling fan on amazon for 10 bucks. Stuck a hard drive magnet on it and mount it to the bottom of something magnetically nonpermeable (thin wood, plastic), and you are in business.

 

[popquizkid]

If you use liquid yeast a lot -- definitely worth it.

It saves a lot of DME and time. We are not talking about an expensive piece of equipment here. Pretty easy to build one for cheap.

I built mine -- very easy. Hardest part was getting the magnets setup properly so the bar would actually spin properly.