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15

So it turns out: The proper amount of oxygen dissolved in wort is 8-10 ppm. Shaking typically yields around 4 ppm. It's possible to achieve as much as 8 ppm with plenty of headspace and LOTS of vigorous shaking. As an example, 5 minutes of shaking a 1.077 wort may only achieve 2.7 ppm. Siphon sprayers will be in the same range. Air with an Oxygen Stone ...


11

It seems that it was used at New Belgium primarily for yeast storage between brews, not fermentation. AFAIK, New Belgium stopped doing it after a short trial (one batch of Fat Tire) when they found it led to premature staling and off flavors. I know of only one controlled test of it on the homebrew level and the tasters in a blind triangle tasting ...


7

Yes; I'd say they do. Even when capping on foam, you're still going to end up with some O2 in the bottles. This usually isn't enough to turn a beer bad, but depending on how long you're planning to age the beer it can make a difference. I'd always use oxygen-absorbing caps on higher gravity beers like barleywines and imperial stouts that I plan to keep in ...


7

More beer has a great guide on taking care of oak barrels which covers cleaning, sanitizing, etc. The overview is: keep it filled so that it doesn't dry out and use a sulfur-dioxide mixture to sanitize. The oak will soak up some of the beer over time, so brew a little extra and keep it on hand to refill as the level goes down. You should also remember that ...


6

What you're asking about is usually called "Hot Side Aeration", or HSA. A few years ago, there was a lot of concern about HSA and people thought that excessive mash stirring or splashing could lead to early staling of beer. Recently, opinion is that HSA is just not a big deal for home brewers. It's something that large, commercial breweries might have to ...


6

In short, depending on the age of the cake there should be no need to re-aerate the wort for growth purposes. Using the full on yeast cake will make fine beer without the need of extra O2 for yeast growth. The downside to this practice is that without some active reproduction going on you don't always get the true flavor profile of the yeast in the beer. ...


6

To quote from http://www.wyeastlab.com/hb_oxygenation.cfm: It was concluded that pumping compressed air through a stone is not an efficient way to provide adequate levels of DO. Traditional splashing and shaking, although laborious, is fairly efficient at dissolving up to 8 ppm oxygen. To increase levels of oxygen, the carboy headspace can be purged with ...


5

It's very much temperature dependent. In an episode of brewstrong, Charlie Bamforth mentions that the rate of oxidization is proportional to temperature, and increases 3 fold for each temperature increase of 10°C/18°F. So, if your beer is stored at 4°C (39°F), it will oxidize 9 times slower than if it's stored at 24°C (75°F). Loosely speaking, if it takes ...


5

Actually I found an article from BYO that says: Uptake of oxygen late in fermentation leads to excessive diacetyl production. Yeast will begin releasing more alpha acetolactate if oxygen is introduced late in the fermentation. This eventually leads to an increase in diacetyl, so care must be taken to avoid oxygen pickup during beer transfers. ...


5

If you're concerned about using good practice, you really shouldn't rack fresh wort onto a used yeast cake. The trub contains a lot more than just healthy yeast, and doing this doesn't allow you to control your pitch rate. I know that doesn't really answer the question, but it seems that your general procedure leaves more room for error than the oxygen ...


4

Little to none, most likely. Between boiling most of the oxygen out, putting more oxygen back in, and then the yeast multiplying and eating up whatever is in suspension, it's really not something you need to worry about. You should definitely be concerned about excessive oxygen post-fermentation, but I don't think it matters much on the hot side.


4

How would you describe the off flavor? Most likely scenario is that the beer picked up an infection somewhere between primary and the keg. Maybe you've got something funky growing in your lagering fridge? In the jumper hose? The keg itself? I'd suggest replacing all the beer line, and sanitizing anything you get bleach on.


3

Oxygenating your wort using a tank is leaps and bounds more efficient (as well as more expensive) than agitation or splashing. Simply agitating or splashing your wort to oxygenate it will work for most average gravity beers (you're aiming for a minimum of eight parts per million of oxygen minimum), but will otherwise require a significant amount of effort ...


3

People have used olive oil with some success, see some conversations here or here. The general consensus is that it works, but most seem to agree that there isn't much point of doing it on the pico scale unless you like to experiment.


3

Even if all the yeast is filtered out of the beer, if there is diacetyl precursor still in solution (alpha acetolactate) the general oxidation of the beer will cause the alpha acetolactate to be converted to diacetyl. This is a non-enzymic, yeast-less process. Minimizing oxygen minimizes this affect, as does minimizing alpha acetolactate content. Look ...


3

With the caveat that I personally don't brew beers that big, let me say that it seems incorrect to suggest that you add oxygen at any point other than prior to the initial yeast pitching. I suggest that you overcome your fear of infection and take a sample now. If the beer is anywhere near final gravity, then you most certainly do NOT want to oxygenate. ...


3

I don't know of any homebrewers that are actually measuring the ppm of O2 dissolved in their wort. The best practice is to get an O2 cylinder with a medical grade flow meter (not a pressure regulator, but a flow meter). Then experiment with time on the meter and good results in the final product.


3

There's a relatively inexpensive procedure, known as the Winkler method, that's used by ecologists to measure the oxygen concentration in streams and ponds. It relies on titration using sodium thiosulfate (among other chemicals). I don't think this test works on wort, however, due to wort chemistry. At the very least, titration would be difficult with any ...


3

I will start by assuming you have an pure O2 tank, regulator, and wand/diffusion stone setup. Because it is impossible for you to over-oxygenate your wort by any method that uses air rather than pure O2. I don't think there is a scientific consensus on how much oxygen is too much, and even measuring oxygen levels is a tricky business. I think there is ...


2

I pour my wort into a bottling bucket and then letting it freefall from the spigot into the fermenting bucket about 2 feet below it. It's easy and it works well for me. I put aeration on the "art" side of brewing as opposed to the "science" side b/c I have no idea how to calculate O2 parts per million in my beer... Also, I watched my buddy "shake" his ...


2

I don't have definitive evidence one way or another, but here's my thoughts on the matter. The two or three times I have pitched onto an existing yeast cake, I have always followed my standard aeration procedure and things have been fine. Good fermentation, etc. My thought is this: If you are going to pitch on an existing yeast cake (setting arguments ...


2

I'm surprised you didn't take a gravity reading when you racked to secondary. The infection risk comes from exposing the beer to atmosphere and potentially contaminated tubing. You can fill a sample jar without adding any extra risk. Throw away or drink the contents of the sample jar, of course. If you've got plenty of fermentable sugars remaining in the ...


2

With some bigger beers I have seen instructions to aerate for the first few days of fermentation, or beers where you add sugar incrementally during fermentation to re-aerate then. Most definitely not after 2 weeks, since fermentation is most likely complete or very near it. There's no point in oxygenating, since the yeast are no longer very active and will ...


2

You can add one eighth a teaspoon of ascorbic acid for 5 gallons. It will mop up a lot of the dissolved oxygen. One campden tablet can also do the same job. However, if there are still yeast in suspension, which there probably is considering you've got it in secondary, then they will naturally scrub out most of the dissolved oxygen as part of the small ...


2

Well the reality is that you need some yeast growth to generate the proper flavor profiles with most all ale yeasts. If you underpitch any given ale yeast vs. super overpitching the ester profiles or main flavor characteristics change significantly. There is an interesting line to be drawn between how much growth and how much esters (etc) however. In the ...


2

I think Tobias is correct. It sounds like you've picked up some wild yeast or bacteria from somewhere. You need to clean everything that beer touches after boiling. I recommend: Replace all of your tubing. Disassemble and soak everything (that is plastic or stainless, including all of the new tubing) overnight in hot water and PBW or Oxiclean. ...


2

Too much oxygen in a starter is almost impossible, so long as you decant the liquid and don't pitch it with the yeast. If you plan to pitch the liquid (e.g. to kraeusen a beer or restart a stuck ferment) then don't stir at all since you'll be pitching oxidized wort. A vortex isn't necessary for oxygen uptake - just having the surface in continual motion ...


1

Hot, fusel alcohol flavors generally correlate to stress in the yeast — insufficient population, not enough nutrients, or insufficient oxygen levels in your starting wort. If you're getting these off flavors for even a smaller beer at 1.050, in the very least do the following: in your boil, add yeast nutrients in the last 15 minutes of the boil, and ...


1

I realize this is answered, but if the beer is tasted better later, I doubt it's an infection. This might be totally off-base, but when you move to a keg and refrigerate, unless you filtered before transferring, the remaining yeast and sediment particles are going to settle to the bottom of the keg. The dip tube on a corny keg is pulling from the bottom, so ...


1

Don't add more O2. If the beer is partially fermented more O2 will create an oxidize character to the beer. Something a Tripel shouldn't have. You need to trust that you can sanitize a racking cane and get a sample for hydrometer testing of the gravity. Its the only way to really answer this question appropriately. When making a beer that big you sort ...



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