flyhigher87 Posted September 19, 2017 Share Posted September 19, 2017 Hey guys!! So question how are you guys aerating your fermenters. I have small 45 gal(180L) ferments and am aerating with an aquarium pump(I know I'm on a budget) for about 30 min just prior to pitching. But I was wondering what you guys were doing and for how long and when. I come from a chemical engineering background and in big industry tanks have air sparging equipment on the bottom of the tanks that create micro-bubbles. But in all my research I have never found or noticed a fermenter with built in air sparging equipment. So what are you guys doing for aeration? Please let me know. Link to comment Share on other sites More sharing options...
Tom Lenerz Posted September 19, 2017 Share Posted September 19, 2017 We are splash filling into the top. We've had no yeast problems for with our bourbon and rye mashes. Link to comment Share on other sites More sharing options...
flyhigher87 Posted September 19, 2017 Author Share Posted September 19, 2017 So my problem is, I am mash cooking in the still, but then I transfer hot mash to the fermenter where I do the actually mashing. So by the time I add yeast it has probably lost the oxygen in the liquid. Thanks for the reply but I think I have to force oxygenate. Link to comment Share on other sites More sharing options...
Tom Lenerz Posted September 19, 2017 Share Posted September 19, 2017 1 hour ago, flyhigher87 said: So my problem is, I am mash cooking in the still, but then I transfer hot mash to the fermenter where I do the actually mashing. So by the time I add yeast it has probably lost the oxygen in the liquid. Thanks for the reply but I think I have to force oxygenate. Are you measuring your DO? Link to comment Share on other sites More sharing options...
Mr_Whiskey Posted September 19, 2017 Share Posted September 19, 2017 for batches that small a paint or drywall mud mixer chucked up in a drill can provide adequate aeration, if you mix near the surface of your mash for a few minutes. Link to comment Share on other sites More sharing options...
Silk City Distillers Posted September 19, 2017 Share Posted September 19, 2017 Second vote for just splash filling. Link to comment Share on other sites More sharing options...
PeteB Posted September 19, 2017 Share Posted September 19, 2017 I splash fill my fermenters, occasionally use a drill for aerating and breaking up lumps of dry yeast. The drill with propeller just under the surface looks as if it does a great job. At my Son's brewpub he has an inline oxygen inducer just after the heat exchanger, bottled oxygen enters a venturi. Brewery fermenters often have oxygenating stones fitted, dual purpose fermenter/brite tanks use the same stone for oxygenating then carbonating. Link to comment Share on other sites More sharing options...
adamOVD Posted September 19, 2017 Share Posted September 19, 2017 While working at a brewery, we also oxygenated through an inline beer stone so the wort is oxygen rich before you even introduce the yeast, but it would have the same effect if you did it in the fermenter before pitching. You can control the time and flow rate for better consistency that way. I believe yeast only requires oxygen during it's reproductive phase though, so depending on what you are pitching, and the rate, oxygen may not even be necessary. Link to comment Share on other sites More sharing options...
indyspirits Posted September 21, 2017 Share Posted September 21, 2017 We try not to oxygenate and simply overpitch. I don't want the yeast doing their aerobic thing, I want them doing their anaerobic thing. 1 Link to comment Share on other sites More sharing options...
Silk City Distillers Posted September 21, 2017 Share Posted September 21, 2017 @Tom Lenerz posed an interesting question - are you folks even measuring DO before you add oxygen? Or, after? How do you even know this is a problem needing to be solved? Link to comment Share on other sites More sharing options...
flyhigher87 Posted September 21, 2017 Author Share Posted September 21, 2017 Valid point on measuring the DO because we do not and we should. If I did do you guys know where I could find info on what is an acceptable range? The only thing I have noticed and I have noticed it quite a few times. If I do not aerate the fermentation the next day has a different smell. A less pleasant smell in my opinion. But wether the pleseant smell is better for the final product I couldn't say. I think the mud mixer is a nice idea, I have one available and it is easier to clean. As far as not oxygenating I am not the most knowledgeable person here but I have read a lot of technical publications, books, researched a lot and have a degree in biochemical engineering. My understanding is that oxygen is very important for the growth phase of the yeasts life, essential. With out a strong growth and reproduction phase you probably will get a low yeast count and your fermentation will take longer than necessary and possibly open you up to infections. But as most know alcohol will not be produced or will produce less in an aerobic environment. So oxygen good for first day or so, bad after. But from my university days it was well understood that yeast in a bioreactor[fermenter) will consume all dissolved oxygen almost instantaneously. So I do not think over oxygenating would ever be a problem as long as you stop adding oxygen around the time of pitching the yeast. Thank you guys! Link to comment Share on other sites More sharing options...
Tom Lenerz Posted September 21, 2017 Share Posted September 21, 2017 This book: https://www.amazon.com/Yeast-Practical-Fermentation-Brewing-Elements/dp/0937381969 has lots of info about oxygen levels, vitality and lots more. Easy read, lots of good info to have on hand for referencing. You could also speak with your yeast supplier about recommended levels, and maybe borrow a DO meter from a local brewery or winery. Link to comment Share on other sites More sharing options...
adamOVD Posted September 22, 2017 Share Posted September 22, 2017 I am not the guy with the most knowledge here either, but this is how I understand it, when making beer, and repitching for multiple generations, the yeast needs oxygen for 2 reasons. So the yeast can reproduce, and also produce sterols and fatty acids used during fermentation. One time at a brewery we ran out of oxygen, and overpitched yeast and added a little olive oil to the wort. Sounds really weird, but apparently they are an easy to find source of sterols. Dry yeast is grown in a oxygen rich environment, and is rich in sterols, and most distiller's mashes are rich in fatty acids, so if you pitch enough, no oxygen needed. Correct me if I'm mistaken. If in the real world it smells better, I guess you can't argue with results. Link to comment Share on other sites More sharing options...
RobertS Posted September 27, 2017 Share Posted September 27, 2017 http://www.kotmf.com/articles/oliveoil.pdf New Belgium put out a paper on using olive oil. It works, but the benefits apply more to beer than to wash. We propagate yeast with oil and feed oxygen in-line during knockout like Pete's son does. Link to comment Share on other sites More sharing options...
flyhigher87 Posted November 23, 2017 Author Share Posted November 23, 2017 Thanks for the read Tom! and Robert when can I come work under you. I read all your posts you are definitely one of the most knowledgeable person on this forum. Always appreciate your input. Link to comment Share on other sites More sharing options...
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