Magnetic Stirrer in Primary?

Howdy all,
I am in my second year of mead-making, and have learned a lot from year one - I think. I just started my first batch for this year, and wanted to try out some of the more sophisticated approaches (SNA, daily stirring, etc). Seems to be helping a LOT!

Right now, I am curious if anyone has attempted to perform the twice-daily degassing on days 1-7 with a magnetic stirrer in the primary bucket (4-5gal)?? It seems that instead of opening the fermenter 2 times a day (and risking contamination), it would be easier to use a magnetic stirrer with enough oomph to move the stirring rod, no?

Has anyone tried this?

n

I haven't read much about degassing as a technique (is this to up the pH?), but if we're talking aeration, I remember reading at some point a test by somebody who used magnetic stirrer to continuously aerate a must. The only detail I recall is that the mead finished fermenting super fast (I read this when I just started brewing, so the details escape me sorry); I don't think it was mentioned how this effected the final aged product however (sometimes super fast ferments can also have a lot of fusel issues).

To me, it seems like a bit of overkill. Have you ever got contaminated mead? I'm guessing not, and even if so, it seems unlikely that it was due to opening the lid to aerate or degas. One of those, if it ain't broke, don't fix it. That said, experimentation is half the fun.

I recently got the new Black Maxx stirplate and it is perfect for this kind of thing, as it's even capable of stirring a 5gal carboy. I'm definitely going to be experimenting with stirred fermentations.

mccann51 said:

I haven't read much about degassing as a technique (is this to up the pH?), but if we're talking aeration, ...

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It appears to me that stirring serves as both. The fermentation is definitely a LOT faster, and seems to get good reviews by several writers whom I assign more authority than myself . There are two docs that indicate that aeration/degassing (I don't think you can aerate w/o degassing, but you can degas w/o aerating) have a very positive impact on the mead. They're linked to in somewhat obscure posts on this site (if I recall), but titled:
"Making Great Mead" by Kristen England and
"Making Mead the Easy Way" by Steve Piatz

England suggests aerating / degassing 2x/day for the first 8 days, and claims great outcomes. Similar for Piatz's memo, but with fewer specifics.

Anyone else?

I highly doubt a stir plate does anything to aerate, because unless you're leaving the top of your fermenter open, there's no oxygen to aerate with. Degas, maybe. Aerate, no.

huesmann said:

I highly doubt a stir plate does anything to aerate, because unless you're leaving the top of your fermenter open, there's no oxygen to aerate with. Degas, maybe. Aerate, no.

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Well, you can always quickly open it up once in a while and let air diffuse back in... with the motion of the stirring, it should actually happen very quickly.

Alternatively, you can occasionally pump air or oxygen into the mead, which will also replenish the headspace (or just fill the headspace).

I have heard some experiments over this. Mostly for making high octane 20% ABV+ mead. I have encountered the stirplate over at GotMead.com.

From what I gather, Fermentation is quicker, more complete, cleared quicker, and it produces less off flavors. I think that this is due to the speed.

Evidently continious agitation or on a regular schedual jostles the yeast around more so that it can reproduce quicker. I have not yet heard how it ages or how it truely improves the product over all. It would be interesting to do a side by side test using exactly the same recipie. I also have wanted to do a step nutrient test vs all in at once.

Mostly, I am lazy. I put all the ingredients, save yeast in my brew pot at once, heat the honeywater only enough to get the honey integrated and aerate it with a spoon, sloshing it about and when it is down to about 80 or so I toss the yeast put in my carboy and leave it alone til racking time. This has produced some really good meads for me. This is why I want to do some side by side tests.

Current Test: Triple Toast: A single honey mead with oaking consisiting of Light, Medium, and Heavy Toasted oak chips all put in the exact same time.

Future Tests:
1. Step nutrient vs all nutrients in at once.

2. Stir Plate vs no stir plate

3. Yeast Test: Several yeasts same batch of must. Keeping in mind the tempatures of my fermenting area.

4. Force Carb vs no Carb, Sweet batch

5. Large Batch pair with Pump

6. Filtered vs Gravity Clearing

Some of these tests will need to wait until I get the equipments for it but With these tests I hope to understand what does what in mead and better put together techniques for given batches.

That's my take anyway.

Matrix

nomile said:

It appears to me that stirring serves as both. The fermentation is definitely a LOT faster, and seems to get good reviews by several writers whom I assign more authority than myself . There are two docs that indicate that aeration/degassing (I don't think you can aerate w/o degassing, but you can degas w/o aerating) have a very positive impact on the mead. They're linked to in somewhat obscure posts on this site (if I recall), but titled:
"Making Great Mead" by Kristen England and
"Making Mead the Easy Way" by Steve Piatz

England suggests aerating / degassing 2x/day for the first 8 days, and claims great outcomes. Similar for Piatz's memo, but with fewer specifics.

Anyone else?

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If we're talking aerating, then I completely agree that it's good for the yeast (helps them reproduce to get up to a suitable population to ferment the must). I haven't heard of degassing being useful, but I will read those two posts.

Matrix's point about agitating them is a good one, but I'd disagree with the reasoning behind it (I may also just be reading the sentence wrong, though). Agitation with the airlock on (or degassing) is just getting the yeast back into suspension and increasing the likelihood of yeast cells bumping into sugar molecules to munch on; I do this for difficult ferments but don't stress about it otherwise. Agitation with the airlock off (aeration) introduces oxygen into the must, which is required for reproduction; I do this for all ferments until the 1/3 sugar break.

mccann51 said:

If we're talking aerating, then I completely agree that it's good for the yeast (helps them reproduce to get up to a suitable population to ferment the must). I haven't heard of degassing being useful, but I will read those two posts.

Matrix's point about agitating them is a good one, but I'd disagree with the reasoning behind it (I may also just be reading the sentence wrong, though). Agitation with the airlock on (or degassing) is just getting the yeast back into suspension and increasing the likelihood of yeast cells bumping into sugar molecules to munch on; I do this for difficult ferments but don't stress about it otherwise. Agitation with the airlock off (aeration) introduces oxygen into the must, which is required for reproduction; I do this for all ferments until the 1/3 sugar break.

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CO2 is actually harmful to yeast. Differing levels ultimately cause the yeast to produce differing ester profiles. Degaussing definitely has a positive effect, although it might not be what you want in terms of flavor (though it very well could be.)

mccann51 said:

If we're talking aerating, then I completely agree that it's good for the yeast (helps them reproduce to get up to a suitable population to ferment the must). I haven't heard of degassing being useful, but I will read those two posts.

Matrix's point about agitating them is a good one, but I'd disagree with the reasoning behind it (I may also just be reading the sentence wrong, though). Agitation with the airlock on (or degassing) is just getting the yeast back into suspension and increasing the likelihood of yeast cells bumping into sugar molecules to munch on; I do this for difficult ferments but don't stress about it otherwise. Agitation with the airlock off (aeration) introduces oxygen into the must, which is required for reproduction; I do this for all ferments until the 1/3 sugar break.

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Agitation, for suspension of yeast, not aeation. Sorry for the confusion. I agree that Aereation is the need to add more O2 into it but I don't see it as very critical. A difficult fermenting one or a particularly heavy must, I will take some and put it in the blender to aereate a bit and mix that in, should be plenty of O2 in the solution. I don't see the need for the O2 stone. Aggitation should lower the disolved CO2 in the solution as well as distribuite the yeast better. I can see a Stir Plate being worth it.

Matrix

Matrix4b said:

Agitation, for suspension of yeast, not aeation. Sorry for the confusion. I agree that Aereation is the need to add more O2 into it but I don't see it as very critical. A difficult fermenting one or a particularly heavy must, I will take some and put it in the blender to aereate a bit and mix that in, should be plenty of O2 in the solution. I don't see the need for the O2 stone. Aggitation should lower the disolved CO2 in the solution as well as distribuite the yeast better. I can see a Stir Plate being worth it.

Matrix

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I would disagree that aeration is not important for mead fermentation; aerating for the first 1/3 of the fermentation is hugely important to get the yeast up to a solid population to finish off the ferment strong. Honey musts are not the best of conditions for yeast, and as ABV rises the nutrients (since usually inorganic YAN in the form of DAP) added are less and less assimilable, so having a high cell count going into the latter portion of the ferment is good to avoid stuck fermentations and stressed out yeast.

I agree that pumping straight O2 seems a bit excessive. I simply pop the airlock off and swirl vigorously for a few minutes.

Interesting to learn about the degassing, btw; I'll have to try agitating (with airlock on) more in the late ferment and see what kind of results I get.