BIG starter=no aeration+cleaner taste

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Alamo_Beer

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I've thought about this before but never really did much research into it bc, well I'm lazy. It makes sense though that if you have enough viable yeast ready to go that you wouldn't need to aerate your wort and that it would start actually fermenting a lot faster.

Anyone try this or have any thoughts? here is a quote from Eric Watson from beer tools:

Yes, as I stated, it is best to only aerate the starter if you are so equipped to do this. The reason is that once the yeast has all the oxygen it needs to build strong cell walls and reproduce, it does not need any more. Any additional oxygen beyond that point will cause them to stay in a reproductive state rather than begin a fermentative state. If you can do this, you will notice a refined smoothness to your beers due to a reduction in ester production and therefore your beer will condition faster.

Since shaking a starter vigorously only produces large bubbles, it is an inefficient and inconsistent practice. I assume if you would do it for a LONG time... say 30 minutes, it would probably be sufficient, but 1) who wants to shake a starter for 30 minutes? & 2) since the air is not sterile, you would definitely risk contamination.

The cost for a pump, tubing, filter and stone shouldn't be more than $35 and the stone can serve as device to force carbonate in kegs that would only take 20 minutes or so. But if this investment is not in your future, go back to the splashing method in the carboy.

Starter sizes are actually cell count/viability dependent. The best practice is to pitch 1 million cells per ml wort per 1 degree plato for ales and 1.5 million cells per ml of wort per degree plato of wort with a cell viability of 96% or more.

Since most home-brewers can't measure cell counts or don't viability tests, The best practice otherwise is to step the yeast culture up one day at a time to 100 ml, 200 ml, 400 ml, 800 ml and finally to 1,000 ml (5 total days of stepping) using a 5 deg. plato hopped wort (remember you want REPRODUCTION not fermentation, this is why the wort gravity is low.) While doing this, aerate 24 hours a day (builds strong cell walls/keeps yeast in a reproductive state) using the air pump/sterile filter method. For a 5 gallon batch, this should be adequate. If you do this, there is absolutely no need to aerate the wort.

http://www.beertools.com/html/articles.php?view=247
 
I think this concept was discussed on a Jamil podcast (can't find it now). It has some merits, but won't work for all beers. English ales, Belgian beers, Hefeweizens, etc. all depend on ester production by yeast for their characteristic flavours. But these esters are produced predominantly during the adaptive phase (reproductive stage) of fermentation. If you eliminate this phase, no esters, no flavour profile.

You will actually see evidence of this popping up every now and then, especially with guys brewing hefes by re-pitching on yeast cakes in the primary. After one or two pitches, they complain that they aren't getting clove and banana flavours. Thats because there is so much yeast available, there is relatively little O2 and little reproduction, so no esters.

Having said that, for beers that you want exceptionally clean (e.g., lagers, some American ales). This could be an idea worth pursuing. I am curious to hear what others think.
 
Sounds like a DIY stirplate is in my future, esp. now that I had 4 HDD magnets :D.
 
greenhornet said:
sucks to read though bc the font is small and its italizised...

Hold down the CTRL key and scroll your mouse wheel forward. You can zoom into the page, making it a lot easier to read. :)
 
Rhino17 said:
Hold down the CTRL key and scroll your mouse wheel forward. You can zoom into the page, making it a lot easier to read. :)


Ahh, good call. Thanks!


here's what the Q and A about phenolics and weizens. I bolded some things I thought were interesting...

Q: In regard to Wort Aeration you said...If possible, don't! The reason is that it is not the wort that needs the oxygen, it is the yeast. By oxgenating the wort instead of the yeast starter, it will cause an over production of cells due to the excessive oxygen presence. This then leads to the production of unwanted esters and higher alcohols that will compromise beer flavor. Many texts on this topic have recommended otherwise. Even Dave Logsdon of Wyeast too advocated the aeration of wort in his Melbourne presentation last month.

However, I am more swayed towards yeast starter aeration rather than wort aeration for the reasons you have suggested, (and also because in an oxygen depleted environment yeast will begin anearobic fermentation rather than aerobic metabolism), but perhaps with one exception.......the brewing of high ester and phenol containing beers such as Weizens. If aeration of weizen wort maintains yeast in a reproductive state than this will increase ester and phenol production. And perhas a short aeration would be more appropriate so as to reduce diacetyl. A diacetyl rest would also reduce this.

Contrary to the literature, I also favourite the pitching of yeast AFTER Kraussen in all non-weizen wort, for the reason that yeast after kraussen is no longer in exponential growth. After Kraussen, yeast will have primed themselves with glycogen stores and other reserves, ready for anaerobic fermentation. For weizen worts however, Kraussen yeast would be more ideal to enhance ester and phenol production.

A: I agree that there is contrary info out there... I was also taught this at both Weihenstephan & Siebel. I agree that wort should be aerated when the volume is over 1 bbl. But in homebrew volumes, aeration of the wort is not as critical. If you do aerate wort, don't do it with pure O2 unless you have the ability to measure dissolved oxgen in solution. Aerate with an aquarium pump, sterile air filter and a stainless stone.

"Contrary to the literature, I also favourite the pitching of yeast AFTER Kraussen in all non-weizen wort, for the reason that yeast after kraussen is no longer in exponential growth. After Kraussen, yeast will have primed themselves with glycogen stores and other reserves, ready for anaerobic fermentation."

Actually the yeast produce glycogen for dormancy not fermentation. If you let them go that far you will be introducing a lag. You want to pitch the yeast pre-krausen. If the yeast is krausening (is that a word?) it is in a fermentation stage not a reproductive stage and the solution would be anaerobic.


"For weizen worts however, Kraussen yeast would be more ideal to enhance ester and phenol production."

Actually for that yeast strain it would not matter as increasing it's ester & phenol producing ability is more temperature dependant than anything else. Volume of pitch can also change that profile somewhat.

*sorry it's so long!
 
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