aeration with O2 and wand

I bought the Williams brewing aeration kit (link) and have been having fermentation issues ever since.

My old method of aeration was to cool and then transfer the 10.5 gal of wort into (3) portions of 3.5 gal each in 5 gal buckets, use a stainless steel whisk and beat the crap out of it. It was effective but time and labor intensive.

I now transfer the cooled wort from the kettle directly to the fermenters, submerge the wand and open the O2 valve slowly until I see O2 bubbles surfacing then stir the wand around for a timed 1 minute.

Since the change I get an active fermentation that starts as normal but slows dramatically after approx 36 hours. I take gravity readings on day 10, and 12 and if no change then rack to a keg on day 14. The last batch, an american amber, started at 1.053 and stopped at 1.020. This has been a typical result for my last 3 batches. I use mostly dry yeast SA04, 05 or Nottingham, rehydrated, 2 pkgs. I ferment in 2 Better Bottles.

This last brew I tried swirling the fermenters when I noticed the krausen dropping in attempt to keep the fermentation going.

The other thing I notice is a significantly smaller yeast cake left after moving the beer to the keg.

All other factors as far as fermentation environment haven't changed so my theory is the wort doesn't have enough O2 saturation to support the needed yeast reproduction to do the job.

How can I be sure I am adding enough O2 to the wort?

I never aerate when using dry yeast and rehydrating. It is unnecessary and a waste of time and money. The yeast mfgs recommend some aeration if dry pitching after pitching the yeast.

So my answer is save the Oxygen for liquid yeast brews.

samc said:

I never aerate when using dry yeast and rehydrating. It is unnecessary and a waste of time and money. The yeast mfgs recommend some aeration if dry pitching after pitching the yeast.

So my answer is save the Oxygen for liquid yeast brews.

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+1

Aeration isn't your problem.

Wait, what? I just found this old thread- dry yeast doesn't require aeration?

I thought all yeast needed food and o2 in order to make alcohol?

badmajon said:

Wait, what? I just found this old thread- dry yeast doesn't require aeration?

I thought all yeast needed food and o2 in order to make alcohol?

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Always a debate topic, but according to one mfg, it's not necessary, I have never done it, although I do try to rehydrate before pitching.



I always aerate my wort when using liquid yeast. Do I need to aerate the wort before pitching dry yeast?
No, there is no need to aerate the wort but it does not harm the yeast either. During its aerobic production, dry yeast accumulates sufficient amounts of unsaturated fatty acids and sterols to produce enough biomass in the first stage of fermentation. The only reason to aerate the wort when using wet yeast is to provide the yeast with oxygen so that it can produce sterols and unsaturated fatty acids which are important parts of the cell membrane and therefore essential for biomass production.
If the slurry from dry yeast fermentation is re-pitched from one batch of beer to another, the wort has to be aerated as with any liquid yeast.


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I've started to aerate twice: one before pitching -- once 18-24 hours after. My beers have turned out much better (subjective, but it's happening on a consistent basis). I aerate for 3-4 mins pre pitching and then another 1.5 mins post-pitching. Use O2 cannister and stone.

I always pitch two full packs Safale 05 for every beer -- 1.050+ -- (overpitching, but I've determined -- again, subjective -- that it's far better to overpitch than underpitch -- especially when several of the brewmasters on Jamil's show have talked about pitching lots of lots of yeast with no conern for the impact of overpitching ) for 90% of my beers. For Kolsch and Belgians, I use liquid years -- but I much prefer working with dry yeast. Never hydrate it -- just pitch both packs directly into the fermenter after dipping briefly in StarSan.

bobbytuck said:

I've started to aerate twice: one before pitching -- once 18-24 hours after. My beers have turned out much better (subjective, but it's happening on a consistent basis). I aerate for 3-4 mins pre pitching and then another 1.5 mins post-pitching. Use O2 cannister and stone.

I always pitch two full packs Safale 05 for every beer -- 1.050+ -- (overpitching, but I've determined -- again, subjective -- that it's far better to overpitch than underpitch -- especially when several of the brewmasters on Jamil's show have talked about pitching lots of lots of yeast with no conern for the impact of overpitching ) for 90% of my beers. For Kolsch and Belgians, I use liquid years -- but I much prefer working with dry yeast. Never hydrate it -- just pitch both packs directly into the fermenter after dipping briefly in StarSan.

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According to the Yeast book up to 50% of yeast can die if you don't rehydrate. That may be why 2 packs for a 1.055 beer (for example) works well for you.