I've been making starters without a stir plate for about 3 months now. I see some online vendors have stir plates for as little as around $45. Is a stir plate worth it? From what I've read, some say you can "set it and forget it" and it "makes your starter ready quicker." But, I have no problem making a starter on Thursday or Friday for a Sunday brew day and just swirl it around every time I walk by. To me, that's not a problem. Besides being able to wait the day before your brew day to make a starter and not having to swirl the flask, is there really a reason to buy a stir plate or is it just a waste of $45?
Are stir plates worth it?
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ThunderpantsBrewing
Well-Known Member
Look in the DIY section of this forum for homemade stir plates. I made mine for free with things I had lying around. And yes, if you value the health of your yeast, it's worth it.
http://www.mrmalty.com/starter_faq.php
http://www.mrmalty.com/starter_faq.php
WoodlandBrew
Well-Known Member
Yeast grown on a stir plate does produce a slightly higher yield. A paper i read recently showed about a 20% increase in yield in a similar arrangement. The growth rate is also faster. It might be healthier for the reasons mentioned in the link above, but in my experience the yeast off a stir plate preforms the same as from a still starter. I made a few stir plates from computer fans and hard drives for a set of experiments. I don't think I wrote up the results, but my opinion is that a stir plate is not wort the trouble for making starters. I do find them useful when preparing matrix assays to keep yeast suspended.
ThunderpantsBrewing
Well-Known Member
Depends on the beer. 20% is not an insignificant amount, and if you're doing anything with a higher gravity or using old yeast, a stir plate would certainly be worth the trouble.
You really want to open a can of worms. The yeast manufacturers say that a single pack of yeast will be sufficient to ferment an ale of up to 1.060 OG but Mr. Malty says you have to make a starter for that. Gordon Strong has said that he often pitches just a single pack of yeast into his lager but Mr. Malty says you have to make a very large starter for that. Who is right? Who is wrong? Will a single package of yeast make good beer and will making a starter make it so much better? Now lets add dry yeast to the mix. Hmmm...Making a starter with dry yeast may give you fewer yeast cells than if you had just rehydrated it and pitched. Are you confused enough yet?
Much depends on the level of oxygen in your wort too because the yeast uses the oxygen with other compounds in the beer to make new cells but oxygen isn't needed in all cases either because dry yeast is packaged with the sterols needed and doesn't need the oxygen in the wort.
Here's a little more reading to help you understand what yeast need or at least make you more confused. http://morebeer.com/articles/oxygen_in_fermentation
A little more info on the effects of overpitching and underpitching yeast. Note that the over pitched batch had 4 times the calculated proper amount and the under pitched one had about 1/7th the calculated proper amount. http://sciencebrewer.com/2012/03/02/pitching-rate-experiment-part-deux-results/
Interesting read. I guess I am pitching at a good rate, though I can't be sure because I ferment in BUCKETS and can not see krausen during the early stages of fermentation. Once I set my airlock, I leave my bucket alone. However, given this quote, "The over-pitch sample never had a lag time (i.e. krausen in an hour!), while the under pitch took 2 days to get a visible krausen. The control pitch had a krausen by 12 hours" I think I had a good pitch rate because my airlock (yes, I know not a sure sign of fermentation, but probably at least a decent indicator) usually starts bubbling about 18 hours or so after pitching.
So, as a follow up, I have a couple questions:
1. Does krausen form before an airlock starts to show activity in your experience?
2. I still don't really see why a stir plate would help besides not having to swirl a flask for a few days. Even if a stir plate might make as much as 20% more cells, couldn't you just make your non-stir plate starter a day earlier and swirl and end up with the same amount of healthy cells?
So, as a follow up, I have a couple questions:
1. Does krausen form before an airlock starts to show activity in your experience?
2. I still don't really see why a stir plate would help besides not having to swirl a flask for a few days. Even if a stir plate might make as much as 20% more cells, couldn't you just make your non-stir plate starter a day earlier and swirl and end up with the same amount of healthy cells?
![Craft A Brew - Safale S-04 Dry Yeast - Fermentis - English Ale Dry Yeast - For English and American Ales and Hard Apple Ciders - Ingredients for Home Brewing - Beer Making Supplies - [1 Pack]](https://m.media-amazon.com/images/I/41fVGNh6JfL._SL500_.jpg)
I bought one of those stir starters for $40, online. Sure, I could have built one from magnets and a project box, etc., but at the time I had some other DIY brew projects going on and was struggling and getting frustrated that things weren't working as I expected so, to spend 0 hours working on something and have it work out of the box was worth it to me.
To answer your question, in my brew set up, a stir plate is 100% worth the investment. I'm not sure it is any faster than not using a stir plate, but you definitely yield more yeast. 20% is significant. Especially, when I brew 11g split batches and only need to buy 1 tube of yeast and can get it all done in a 2L flask for most batches, if I do a bigger beer I might have to step it up, but no biggie because I can get it done on the stir plate.
Fortunately, stir plates aren't one of those things you "NEED" to make good beer as is fermentation temps, healthy and adequate yeast pitch, etc. Rather, it is one of many solutions to get you to the goal of pitching enough yeast. There are alternative: Buy more yeast, brew a smaller beer and harvest yeast to brew a bigger beer, etc.
A stir plate is something you should probably wait until you are prepping for a brew day and say to yourself, "I'm really at my limit for yeast propagation, man, a stir plate would really help right now!" When you find yourself saying that a few times, then its time to buy a stir plate. That is how it went for me, as I started with the walk by and shake method. But when you start playing around on yeastcalc.com and mrmalty.com and realize how much more yeast you can yield using a stir plate you might chose to buy one.
To answer your question, in my brew set up, a stir plate is 100% worth the investment. I'm not sure it is any faster than not using a stir plate, but you definitely yield more yeast. 20% is significant. Especially, when I brew 11g split batches and only need to buy 1 tube of yeast and can get it all done in a 2L flask for most batches, if I do a bigger beer I might have to step it up, but no biggie because I can get it done on the stir plate.
Fortunately, stir plates aren't one of those things you "NEED" to make good beer as is fermentation temps, healthy and adequate yeast pitch, etc. Rather, it is one of many solutions to get you to the goal of pitching enough yeast. There are alternative: Buy more yeast, brew a smaller beer and harvest yeast to brew a bigger beer, etc.
A stir plate is something you should probably wait until you are prepping for a brew day and say to yourself, "I'm really at my limit for yeast propagation, man, a stir plate would really help right now!" When you find yourself saying that a few times, then its time to buy a stir plate. That is how it went for me, as I started with the walk by and shake method. But when you start playing around on yeastcalc.com and mrmalty.com and realize how much more yeast you can yield using a stir plate you might chose to buy one.
WoodlandBrew
Well-Known Member
Let me clarify the 20% number. The shake flask yield was 20% higher than the nitrogen purged anaerobic yield. A stir plate is similar to the shake flask test used in the paper, and a periodically stirred starter has oxygen available which the purely anaerobic did not in this study. So I would suspect that based on this paper the difference would be somewhere between 0% and 20%. Tests I have done show that the yield is about the same (yield difference was smaller than the standard deviation of measurements) for stir plates and still starters if they are allowed to run to completion. However, most on-line calculators will show a difference between the two methods. My guess is that this is because starters are typically only run for 48 hours which may be enough time for it to complete on a stir plate, but not enough time without agitation.
My opinion is that a stir plate can be fun. It was novel to build, and I enjoy using it. Sometimes it seems to improve my work flow when running experiments. It may have indirectly improved my beer by helping me to understand yeast growth better, but I don't think my beer is better directly because of the stir plate. (For me, in my opinion, it doesn't seem to make noticeably more or better yeast)
My opinion is that a stir plate can be fun. It was novel to build, and I enjoy using it. Sometimes it seems to improve my work flow when running experiments. It may have indirectly improved my beer by helping me to understand yeast growth better, but I don't think my beer is better directly because of the stir plate. (For me, in my opinion, it doesn't seem to make noticeably more or better yeast)
1. Airlocks can show activity with changes in barometric pressure, temperature fluctuation, etc.
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
The stir plate may give only a small difference in yield over the "occasionally shake" method. But with the latter, if no one's at home for periods of time (i.e., you're at work), that flask won't get shaken.
skw
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Depending on who you ask, stir plates make a big difference:
http://www.maltosefalcons.com/tech/yeast-propagation-and-maintenance-principles-and-practices
I built mine from scrap parts that I had any way. Total cost: $.50 for the stir bar.
http://www.maltosefalcons.com/tech/yeast-propagation-and-maintenance-principles-and-practices
I built mine from scrap parts that I had any way. Total cost: $.50 for the stir bar.
MaddBaggins
cervisiam vitae
One of these days I'll build a stir plate. I think it would be nice to have for sure.
I just have a 1g growler that I swirl and shake whenever I pass thru the kitchen.
I just have a 1g growler that I swirl and shake whenever I pass thru the kitchen.
Black Island Brewer
An Ode to Beer
I think RM-MN kinda hit it on the head about the "can of worms". There is a lot of information on yeast growth rates and yeast health that seems contradictory. When Chris White is insisting that a single vial is "enough" for a batch (up to, what is it, 1.070?), but Fix suggesting pitch rates of 75/150m cells per ml/degree plato, Jamil, CW and Kai all with their predicted growth rates...ugh.
Before you ask if a stir plate is necessary, you almost have to go back to "is a starter necessary", and then go from there.
I prefer using a stir plate, I like using Kai's calculations, and I like to think I'm managing not just the fermentation itself, but the flavors produced during fermentation, by controlling my pitch rate, my fermentation temperatures and my oxygenation. But since I only brew twice a month, and rarely brew the same beer twice, I'm just trusting that what I'm doing makes a difference. I stand on the shoulders of giants, and hope I'm on the right shoulders...
Before you ask if a stir plate is necessary, you almost have to go back to "is a starter necessary", and then go from there.
I prefer using a stir plate, I like using Kai's calculations, and I like to think I'm managing not just the fermentation itself, but the flavors produced during fermentation, by controlling my pitch rate, my fermentation temperatures and my oxygenation. But since I only brew twice a month, and rarely brew the same beer twice, I'm just trusting that what I'm doing makes a difference. I stand on the shoulders of giants, and hope I'm on the right shoulders...
cantrell00
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Not according to the statistics @ Mr. Malty..
TheZymurgist
Well-Known Member
Not at all. You get much more oxygen introduced to the wort (and CO2 expelled) with a stir plate. Unless you're assuming the starter on the stir plate hasn't finished by the time you're pitching it, but that wouldn't make sense.
Whether it's worth it to you all depends on what you value, but you can't deny the research that has proven that you get more growth with a stir plate than with simple agitation. To get the same growth from a 2L stir plate starter, you'd have to do a 4.5L agitated starter. If you have a 1 gallon jug and don't mind using more DME, then a stir plate isn't necessary. However, a less expensive (or DIY, especially) stir plate will pay for itself eventually, just in savings on DME.
I'm sure everyone thats gotten a stir plate will tell you its worth the investment. And there's gotta be a reason why vendors make and carry them...
But a stir plate is probably near dead last on my wish list of equipment. I'm not going to drop a bunch of money on something I can more or less do myself, with slightly less effectiveness, when there is so much other equipment out there. Like I can't regulate the temperature of a beer by myself or force carbonate and serve my beer with my own hands, but I can shake a yeast starter or 5gal batch to oxygenate
But a stir plate is probably near dead last on my wish list of equipment. I'm not going to drop a bunch of money on something I can more or less do myself, with slightly less effectiveness, when there is so much other equipment out there. Like I can't regulate the temperature of a beer by myself or force carbonate and serve my beer with my own hands, but I can shake a yeast starter or 5gal batch to oxygenate
LLBeanJ
Well-Known Member
If you don't do starters, but are happy with your beer, then you won't think starters are worth it. You certainly won't need a stir plate.
If you do make starters, but don't use a stir plate, and are happy with your beer, then you probably think starters are worth it, but a stir plate is unnecessary.
I make starters. Never brewed without one, except when I've direct pitched slurry from a previous batch. I have a stir plate. I think it's worth it. I like the higher growth rate it produces. I like that I can put my starter on the plate and not think about it for 24-36 hours. I believe the stir plate makes for more consistent results because there's no reliance on my periodic intervention as the starter ferments out. Maybe it's all BS and it doesn't really make a bit of difference. I don't really know. But what I do know is that for me my stir plate = convenience. I'm at the age and place in my life where convenience is more important to me than cost, so I use one for that reason alone. I've spent a lot of money on this hobby over the past few years and I'm sure I'll spend a lot more moving forward and in the grand scheme of things, the cost of my stir plate was a drop in the bucket. If mine quit working tomorrow, I'd run right out and buy another, assuming I couldn't repair it. I also realize that not everyone reading this has the luxury of being able to prioritize convenience ahead of cost.
It all comes down to the individual. We all have different priorities and motivations, so whether a piece of equipment is worth paying for or not will depend on what's important to you.
If you do make starters, but don't use a stir plate, and are happy with your beer, then you probably think starters are worth it, but a stir plate is unnecessary.
I make starters. Never brewed without one, except when I've direct pitched slurry from a previous batch. I have a stir plate. I think it's worth it. I like the higher growth rate it produces. I like that I can put my starter on the plate and not think about it for 24-36 hours. I believe the stir plate makes for more consistent results because there's no reliance on my periodic intervention as the starter ferments out. Maybe it's all BS and it doesn't really make a bit of difference. I don't really know. But what I do know is that for me my stir plate = convenience. I'm at the age and place in my life where convenience is more important to me than cost, so I use one for that reason alone. I've spent a lot of money on this hobby over the past few years and I'm sure I'll spend a lot more moving forward and in the grand scheme of things, the cost of my stir plate was a drop in the bucket. If mine quit working tomorrow, I'd run right out and buy another, assuming I couldn't repair it. I also realize that not everyone reading this has the luxury of being able to prioritize convenience ahead of cost.
It all comes down to the individual. We all have different priorities and motivations, so whether a piece of equipment is worth paying for or not will depend on what's important to you.
The real purpose of the stir plate is to accelerate the growth of the yeast, to promote reproduction to get sufficient cells to be able to complete the ferment without being so stress that they create flavor compounds that are not intended. This gets you a lot more cells than is in a pack of liquid yeast so they are ready to go to work immediately, eliminating the lag time that would otherwise exist. If you are in a hurry, you need the stir plate. Otherwise, you can make a starter earlier and let it go to completion and get nearly the same amount, within the range that makes good beer. The third alternative is to allow the lag time to happen in your fermenter because the yeast will reproduce there if there is sufficient oxygen present. With enough oxygen dissolved in the wort, a single pack of liquid yeast will produce plenty of cells to make good beer. I'm pretty sure that is what Gordon Strong does to get a good tasting lager with only a single pack.
WoodlandBrew
Well-Known Member
Yes, the yield is about the same. It will just take longer to get there.
When allowed to run to completion the yield on a stir plate is about the same as an occasionally shaken starter. The data collected by Camacho-Ruiz [1] shows that the yield for a shake flask culture stirred at 300 rpm has a yield was only 9% higher than one that is not stirred. However, the growth rate was 2.6 times faster when stirred than when stationary. Ariff [2] found that for stirring rates of 200 to 1200 rpm the yield was constant. Ariff also noted "a slight decrease in cell viability was observed with increasing agitation speed." This is also consistent with Camacho-Ruiz's findings.
In laboratory shake flask growth the propagation time is typically 48 hours. Because unstirred startes grow slower the yeild at 48 hours will be lower, but if allowed to run to completion they will be very close to the starter on a stir plate.
[1] Factors Affecting the Growth of Saccharomyces Cerevisiae in Barch Cultures and in Solid State Fermentation, 2003
[2] Development of Fermentation Technique for High Cell Density Cultivation of Saccharomyces Cerevisae, 2005
Okay - so long story short, if I have $ to burn and think swirling a stir plate is annoying, it's worth $50, otherwise, it's not worth it to me. It could be a purchase, but it's certainly not a pressing need. Thanks guys for the honest input. Have a great weekend 
Black Island Brewer
An Ode to Beer
I appreciate the references, thanks, I might check them out.
I have a question about the "laboratory shake flask" - is that a device, or does it mean occasionally stirring the flask?
DurtyChemist
Well-Known Member
Glad I stumbled on to this. I usually stir my starters during brew day. Pretty easy to do or even while watching tv.
Okay - just to "stir" things up once more here - can you swirl a flask "too aggressively" if you don't use a stir plate? I usually swirl it up pretty good so there can be as much as 3-4" of foam at its peak before it settles back down again.
TopherM
Well-Known Member
I made my stir plate for $3.00. Well worth it
WoodlandBrew
Well-Known Member
Shake Flask is another name for an Erlenmeyer Flask. A Shake Flask Culture normally implies that the flask is actually agitated in some way. This could be a stir plate or an orbital shaker platform. A Shake Flask Batch Culture is a Shake Flask Culture where everything is added at the same time and then incubated. (the Shake Flask Batch Culture is the most similar to the way hombrewers use stir plates) A Shake Flask Fed Culture is inoculated and incubated, but the carbon source is fed over time. And then there is a Chemostat This is the type of machine that yeast producers use for propagation. The yield is about 10 times that of a stir plate.
Twinkeelfool
Well-Known Member
I find stir plates are excellent for reviving older yeast samples. Much more consistent. In general I'm a big fan of them.
I use a stir plate, got one prebuilt from StirStarters when he sold them directly off his site. I seem to recall it being cheaper than $45 but it was worth it. Shaking sucks, not just because you get much less O2 and frequent flocculation that needs to be kicked up, but because when you shake it up it erupts like Mount Vesuvius. After the first time or two I didn't even attempt to shake anymore, I just gently rotated it cylindrically to stir up the yeast. With a starter there's no having to monitor it, not worry about shaking and having it burst over with foam, more O2 into the starter for the yeast, and much better yeast reproduction. Many here are quoting a 20% increase but everything I'd read stated a way higher amount, closer to what is in the maltosefalcons link posted earlier.
Rev.
Rev.
Brew_G
Well-Known Member
I built a stir plate for about $20, and as someone who is looking to save here and there I find it well worth it. But I also have a young family that keeps me and my wife busy, so for my starter I can set it...and? Forget it!
