35 replies to this topic

[MolBasser]

Oxygenating an already fermented beer = very bad.

This.MolBasser

[Tankard]

This.MolBasser

Y..yes, I already dumped the batch.

[Tankard]

You prolly just killed this beer in terms of flavor. Oxygen at this point in the process is the enemy.A beer of the gravity you described, should be done fermenting in 4 days tops if pitched properly. I would have just tossed in a pack of dry yeast and prayed.If I were you, I would re brew and chock it up to experience.MolBasser

You're late to the party.

[MolBasser]

Since the OG on this beer is so low (1.040-1.044), how long should I add oxygen? The problem with my oxygenation setup is that I don't know the flow rate. I turn it on at such a level that the foaming does not become excessive (there's enough of a flow to generate a good amount of churning inside the carboy, however). I'm just worried that pure O2 is going to thin out the beer too much, since this beer is already quite light.

Over oxygenated will not "thin" your beer. The way the maltster made your syrup and the fermentable sugars within it will dictate your final gravity (along with yeast strain and pitching amount).The danger is that you will poison your yeast with too much oxygen. Unless you really can measure how much your adding just use air. Oxygen for a home brewer (and ESPECIALLY with such a small beer) is total overkill.My guesses as to why your last beer crapped out was:1. Underpitch (no starter, always ALWAYS, make a starter)2. Over oxygen.MolBasser

[Tankard]

Over oxygenated will not "thin" your beer. The way the maltster made your syrup and the fermentable sugars within it will dictate your final gravity (along with yeast strain and pitching amount).The danger is that you will poison your yeast with too much oxygen. Unless you really can measure how much your adding just use air. Oxygen for a home brewer (and ESPECIALLY with such a small beer) is total overkill.My guesses as to why your last beer crapped out was:1. Underpitch (no starter, always ALWAYS, make a starter)2. Over oxygen.MolBasser

By "thin" I did not mean that it would decrease the gravity of the beer. From what I've read, adding pure o2 for too long can cause the beer to have less flavor, due to it fermenting "too cleanly" with very little character given off by the yeast. As for your guesses,1) I used dry yeast, and rehydrated. For a gravity this low, 1 packet of dry yeast should have been plenty. No need for a starter with dry yeast. 2) The only oxygen I introduced is whatever was picked up as I poured from the stock pot to the fermenter. I didn't add o2 or shake the carboy around. This time, I pitched a little warmer (73 degrees, as opposed to 65), and added only 15 seconds of bottled o2. Hopefully this will result in a better fermentation.

[davelew]

By "thin" I did not mean that it would decrease the gravity of the beer. From what I've read, adding pure o2 for too long can cause the beer to have less flavor, due to it fermenting "too cleanly" with very little character given off by the yeast. As for your guesses,1) I used dry yeast, and rehydrated. For a gravity this low, 1 packet of dry yeast should have been plenty. No need for a starter with dry yeast. 2) The only oxygen I introduced is whatever was picked up as I poured from the stock pot to the fermenter. I didn't add o2 or shake the carboy around. This time, I pitched a little warmer (73 degrees, as opposed to 65), and added only 15 seconds of bottled o2. Hopefully this will result in a better fermentation.

Your original process with the yeast seems correct to me. Dry yeast without a starter shouldn't need any oxygen. Danstar or whoever makes your yeast makes sure the yeast has absorbed all the oxygen it can before packaging it.Adding 15 second of O2 to your second batch probably didn't help, but I don't think it hurt either.My guess is that one of four things happened with your first batch:1. damaged yeast that got too hot or otherwise stressed2. cold fermenter that was too cold for the yeast to work quickly3. stale or otherwise damaged malt extract4. bad hydrometer

[Mya]

1. Underpitch (no starter, always ALWAYS, make a starter)MolBasser

he used dry yeastI suspect he had less than fully viable yeast

[MolBasser]

Which is why you ALWAYS make a starter.MolBasser

[Tankard]

Jeez not again. Fermentation started 7 hours or so after I pitched. It's been 14 hours now, and there is barely an inch of krausen on the top, and a bubble every 1-2 seconds. I thought it would be roaring by now, especially since I added O2 and kept the wort at a warmer temperature.What should I do

[positiveContact]

Which is why you ALWAYS make a starter.MolBasser

I'm going to go against the pro here. starters are not required when using good quality dry yeast (not super old, stored properly). I would recommend rehydrating 10-15 mins before pitching but definitely no starter.

[Mya]

Which is why you ALWAYS make a starter.MolBasser

not with dry, correct?an 11 gram packet of Dry yeast should be an overpitch for a 1.044 wort, unless it was too old

[davelew]

Jeez not again. Fermentation started 7 hours or so after I pitched. It's been 14 hours now, and there is barely an inch of krausen on the top, and a bubble every 1-2 seconds. I thought it would be roaring by now, especially since I added O2 and kept the wort at a warmer temperature.What should I do

Relax, don't worry, have a homebrew. At 14 hours, an inch of krausen and a bubble every 1-2 seconds are good signs. I expect your beer will be fine.

[Mya]

what particular dry yeast was this, how do you store it, and do you still have the package with the dates and lot numbers on it?

Edited by miccullen, 14 August 2011 - 11:23 AM.

[MolBasser]

I'm guessing bad yeast, which would have been obviated by a starter.I will repeat until horse.ALWAYS make a starter.MolBasser

[Brauer]

[Brauer]

Is it possible you are rehydrating at too high a temperature? Have you calibrated your thermometer lately?Also, I don't think it's a good idea to pitch warm, then cool. That can stall even healthy yeast.But like Davelew said, activity at 14 hours sounds pretty reasonable.