Aeration Stone

[dfwwino]

As I mentioned in another post on Orange Blossom Honey Mead in Meadmaking, last night I used an aeration stone I have used for many years to aerate wort before pitching yeast when making beer. The device is an aquarium pump with a sterile filter and a wand and aeration stone attached. I place it in the wort and leave it for 20 minutes while it pumps the wort full of air. The aeration stone and use of a degassing drill had a tremendous effect on a quick start to my mead. Is there any reason why I should not use an aeration stone on wine must before pitching yeast? I know oxygen after fermentation ends is a no-no, but I don't see the downside of aerating the must in this manner before fermentation. I am amazed no one has carried over this homebrewing device to the winemaking side or discussed it in the homebrewing literature I've read. Any comments would be appreciated.

 

[Dean]

I think your aeration stone idea is great! If anything, a wort is MUCH more prone to spoilage than wine must. I have a stainless steel air stone that works much the same way. I use it for beer, but never has used it for wine. I dunno why. I just stir the heck out of the must using a drill mounted whip. I think your idea is awesome in creating an environment that yeast would love to get started in!

 

[Funky Fish]

I think it's pretty much unnecessary. You should be able to get all the oxygen that the yeast needs in the must by stirring - either by hand or with a drill-mounted device. That's why it hasn't carried over to winemaking. Using an aeration stone after stirring is kind of like using one no-rinse sanitizer (like one step) after using another one (like easy clean).


That's just my opinion, of course - I'm sure there are other, more official, reasons why it hasn't really carried over to home winemaking like it has with beermaking.Edited by: Funky Fish

 

[Dean]

I think I just found out why it has not really carried overy to winemaking. Time under the stone. When gravities get about 1.075, it takes over 40 minutes on an aquarium pump to sufficiently oxygenate the must. If you get to a typical 1.090 or higher, it will take about 1 hour on the stone. I can do the same thing with my drill mounted stirrer in about 2-3 minutes. If you were going to use pure oxygen, then a must with a gravity of 1.090 would take about 9 minutes of oxygen to fully saturate.

 

[masta]

That is good info Dean...thanks


I have also used a s/s stone with pure filtered oxygen from a cylinder before pitching yeast in beer. Then the cylinder went empty and I just starting using my drill mounted Fizz-X and did not notice much difference in the amount of time it took to start fermentation.

 

[dfwwino]

Thanks for all the input. It would be nice to see a study of which is more effective in aeration: the drill method or anaeration stone. If the drill method is more effective and only takes three minutes to achieve the same aeration, then that means we should eliminate aeration stones on the beermaking side and use a drill method of aeration. I don't think hand-stirring achieves the same level of aeration as an aeration stone. I also don't think shaking five gallons of wort by hand is as effective. I did both in the past and my aeration stone was a vast improvement. I guess I'll have to do some side-by-side testing of the drill method and the aeration stone on a similar batch of wort and a similar batch of must and see what happens. One or the other is the better device and it would seem better to apply the same device to both beermaking and winemaking. If Masta's experience is the norm, then our beermaking buddies are missing out on a much faster and easier device to quickly aerate wort and pitch yeast.Edited by: dfwwino

 

[Dean]

Ah, but Dfw, you are forgetting that wort has a much higher PH and is very much more prone to spoilage organisms. All that extra whipping can cause potential spoilage bacteria to get into the wort. I think that is where the stone is more effective. You do have to be careful with the stone and using pure oxygen as you can over aerate the must, which will cause the yeast to provide off flavors.

For wine, I think the drill method is more effective in the short period of time, whereas the stone method is more thorough. For a wine must, to wait 1 hour on the stone, when you can accomplish enough of an aeration with a drill in 3 minutes to ensure healthy fermentation is a big drawback to using the stone. It seems that high gravity musts and worts do not readily accept oxygen. I'll see if I can find an online source that explains this. I'm going off memory from a brew mag that I read on aerating wort. I extrapolated the high gravity stuff as they talk about almost 1 hour on the stone for doppelbock 1.075+ worts. If I can find a link, I'll post it.Edited by: Dean

 

[dfwwino]

Dean,


I am fully aware that wort has a greater risk of contamination. However, I fail to see how using a sanitized stirrer for two minutes raises a significant risk of contamination. For years, homebrewers have been told to shake a carboy back and forth to add oxygen to wort or to splash wort during racking from a kettle to fermenter to achieve aeration. I fail to see the significant risk if sanitation practices arestrictly followed. I have not had any problems since my first year of brewing 12 years ago with off flavors due to contamination, and even that was due to the lack of a wort chiller and letting wort sit for hours to cool before pitching yeast. I also am curious why we use a stirrer to drive CO2 OUT ofsolution, but believe it will drive oxygen INTO solution at the same quantity as anaeration stone. I think for most wine musts, aeration is not a critical factor. But I think aeration is very important for meads and the possiblity of adding an aeration stone to a stuck fermentation may have merit. When I first began making wine and beer in 1994, I was told to boil wort for an hour as an extract brewer to avoid contamination. Now we know that is not necessary, as late extract addition demonstrates. When I began, I was told to boil honey to sanitize it. Then I was told to hold it at 160 F to pasteurize it. Now, as Masta informed me, the preferred method is no heat at all based on scientific evidence that honey does not raise the same sanitation concerns.I wish we would not accept past assumptions that arose when homebrewers and winemakers had poor sanitation practices andinadequate resources and knowledge, and poor quality homebrewing supplies and apply the scientific methodolgyto current homebrewing and home winemaking, just as the Aussies are doing for commercial winemaking. Are there any studies of how much oxygen is added by stirring with a drill, versus hand-stirring, versus an aeration stone? Perhaps this material is available, but I have not read it in my extensive review of hobby literature.

 

[dfwwino]

Another way the wine stirrer would be useful for beermaking is at kettle knockout. Most homebrewing texts advise taking a sanitized spoon to create a whirlpool effect by rapidly stirring the wort in the kettle in a circular motion and then stopping, which causes the trub to collect in the middle of the kettle. Thus, you can avoid transfering trub to your fermenter. I have never had great success collecting trub by hand-stirring. It seems to only do a partial job. After seeing the whirpool created by my drill mixer in wine, I imagine it willl do a much better job at creating a whirlpool to collect trub in my wort kettle.

 

[Funky Fish]

DFW,


I'm not sure if anyone has every studied how much oxygen is added to a must for wine by stirring versus drill-mounted mixers versus aeration stones. But just look at experience. Experience has shown that you can get enough oxygen in a must to support a healthy fermentation by stirring with a sanitized spoon. Does that mean you shouldn't use an aeration stone? No - it's completely your choice. Some people clean AND sanitize their equipment after they use it. Is it necessary to sanitize your stuff before you put it away, especially considering that you'll sanitize it again when you pull it back out? No, but again - it's a personal choice.


It's kind of like using a yeast starter for wine kits. The manufacturers recommend sprinkling the yeast on top the must. Experience (and probably 50 million bench trials) has shown this works. But some winemakers prefer using starters - every time, even with kits. So if you are wanting to use aeration stones and oxygen on your wine must, then I say go for it - it's your choice and your $$$ after all.

 

[Dean]

Ok, I did my search and remembered that I read this in "Brew You Own" magazine. This is a public that is a sister publication to winemaker magazine for those who don't know.

In the May-June issue of this year, there was an article by Garrett Heaney called Aeration 101. While I won't type out the full article he goes on to state that there are basically 3 type of aeration; shaking, splash racking and air stone injection.

He says that shaking is effective but difficult at larger volumes! (no doubt!) He also states that this is the least efficient method, but still can improve oxygen content.

Next he goes on to say that splash racking or splash pouring from 1 bucket to another is much more efficient, but involves a greater risk for contamination from open air which contains only ~20% oxygen and differing degrees of bacteria. To minimize contamination risk, he recommends only doing this in an area where you believe that the air is cleanest and clearest.

Finally he goes on to explain that oxygen injection is the safest, most effective and sanitary method available to home brewers. He offers the following guidelines for using an air stone: 1.030-10.45SG worts aerate for 5 minutes or 1 minute with pure O2; 1.045-1.060 aerate for 10 minutes or 2 minutes on pure O2; 1.060-1.075 aerate for 20 minutes or 4 minutes with pure O2; and 1.075 and higher for 40 minutes with air or 9 minutes with pure O2. He also warns about over-aerating as that can lead to shocked and over-stimulated yeast that can generate off flavors during fermentation.

Unfortunately, he doesn't state what he used as a reference for those numbers. As a home winemaker, like we all are, I'm not sure that I would want to wait 40-60 minutes for a must to oxygenate. I would have already properly sulphited and had a low enough PH to make sure that whipping the must wouldn't get too many baddies in the liquid. I'm much more paranoid with beer.

 

[dfwwino]

Dean,


Thanks for your information. I agree that for the typical wine must, I don't want to leave an aeration stone in for an hour. But in a stuck fermentation or for a mead must, I'd give it a try. I usually have plenty of clean up to do while the aeration is underway.


Also, given your concern about contamination in beermaking, I thought this would give you a scare given the lenghty aeration of wort. In the current September 2006 issue of Brew Your Own, in an article entitled Five Extreme Beer Recipes by Sam Calagione, the founder of Dogfish Head Craft Brewery, there isa recipe for a 14-16 % ABV "Dema Goddess Ale" that calls for the use of an aeration stone for one hour before pitching in the primary. After primary fermentation and racking to a secondary, he thenrecommends usingan aeration stone in the fermenting wort for another hourbefore pitching a second yeast. Edited by: dfwwino