This doesn't look good
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Re: This doesn't look good
Had this happen a couple weeks ago. Turns out really low ph will cause lag time.
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ScrewyBrewer
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Re: This doesn't look good
I've found that long lag times in starters usually point to low viable cell counts, remedy is to make another starter after decanting the wort off of the first starter. Now you should have enough viable cells to pitch into your beer. I'm not saying everyone always has enough time to prepare their yeast that much, brewing is pretty much done as time allows for most of us.
Long lag times after pitching your yeast also points to some problem with the yeast too. Think of it this way initially the yeast will use up all the oxygen in the wort as they multiply and build up strength to ferment your beer. It's only after all of the oxygen in the wort has been used up that the yeast shift gears and start turning sugars into cO2 and alcohol. While building up their strength the yeast create flavor precursors, the longer the lag time the more the precursors. If too many precursors have been created the yeast may not be able to convert them all before going dormant and your beer will have off flavors.
You'll still end up with beer but it won't attenuate down as low as it would have if fermented quickly with a short lag time. This will leave the beer tasting sweeter and with some unexpected flavors. I know you've all heard me say a thousand times over the years but its true, I like to pitch the healthiest yeast possible and expect to see bubbling in the starter flask or fermentor within 6-8 hours. If the starter takes too long, I know I'll be making another one to step up the yeast counts before using it to ferment beer.
Long lag times after pitching your yeast also points to some problem with the yeast too. Think of it this way initially the yeast will use up all the oxygen in the wort as they multiply and build up strength to ferment your beer. It's only after all of the oxygen in the wort has been used up that the yeast shift gears and start turning sugars into cO2 and alcohol. While building up their strength the yeast create flavor precursors, the longer the lag time the more the precursors. If too many precursors have been created the yeast may not be able to convert them all before going dormant and your beer will have off flavors.
You'll still end up with beer but it won't attenuate down as low as it would have if fermented quickly with a short lag time. This will leave the beer tasting sweeter and with some unexpected flavors. I know you've all heard me say a thousand times over the years but its true, I like to pitch the healthiest yeast possible and expect to see bubbling in the starter flask or fermentor within 6-8 hours. If the starter takes too long, I know I'll be making another one to step up the yeast counts before using it to ferment beer.
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Re: This doesn't look good
Couple of things:
> Think of it this way initially the yeast will use up all the oxygen in the wort as they multiply and build up strength to ferment your beer
This is true as long as they have enough other nutrients. Once they run out of ANY nutrient necessary to continue the growth phase, they will switch to active fermentation. Oxygen is just one of those nutrients.
This is also why over oxygenating your wort can increase lag times. Oxygenating your wort is good - up to a point. Beyond that point you do grow more daughter cells, but you may increase lag time and create more of the flavor compounds you are talking about in the process as long as enough other nutrients remain to allow growth.
> You'll still end up with beer but it won't attenuate down as low as it would have if fermented quickly with a short lag time
This is not necessarily true. Experiments have shown the opposite effect with underpitched wort as long as it's got plenty of nutrients and oxygen. Because in effect your wort acts as a huge starter as long as it has plenty of oxygen and nutrients. The cells that grow in the wort (or your stir starter) are hungry daughter cells and want to chew up the beer when it comes to active fermentation time. An underptiched beer can make MORE daughter cells before they switch to active fermentation given enough oxygen and nutrients. So it can actually hyper attenuate, just like an overpitch, which is what it ends up as from a cell count perspective in this scenario.
That doesn't mean it tastes right. The growth phase is still extended - even massively extended - depending on the oxygen/nutrients available. So yes, all those extra flavor compounds are created and may not be removed as you say.
This would mostly occur if you used an O2 system to oxygenate your wort. This can get more oxygen into your beer then a stir plate starter did to your starter. Easily.
That said, folks who don't oxygenate their wort well would get the under attenuating effect you describe for sure because it will limit the growth phase and not enough daughter cells will be produced.
> Think of it this way initially the yeast will use up all the oxygen in the wort as they multiply and build up strength to ferment your beer
This is true as long as they have enough other nutrients. Once they run out of ANY nutrient necessary to continue the growth phase, they will switch to active fermentation. Oxygen is just one of those nutrients.
This is also why over oxygenating your wort can increase lag times. Oxygenating your wort is good - up to a point. Beyond that point you do grow more daughter cells, but you may increase lag time and create more of the flavor compounds you are talking about in the process as long as enough other nutrients remain to allow growth.
> You'll still end up with beer but it won't attenuate down as low as it would have if fermented quickly with a short lag time
This is not necessarily true. Experiments have shown the opposite effect with underpitched wort as long as it's got plenty of nutrients and oxygen. Because in effect your wort acts as a huge starter as long as it has plenty of oxygen and nutrients. The cells that grow in the wort (or your stir starter) are hungry daughter cells and want to chew up the beer when it comes to active fermentation time. An underptiched beer can make MORE daughter cells before they switch to active fermentation given enough oxygen and nutrients. So it can actually hyper attenuate, just like an overpitch, which is what it ends up as from a cell count perspective in this scenario.
That doesn't mean it tastes right. The growth phase is still extended - even massively extended - depending on the oxygen/nutrients available. So yes, all those extra flavor compounds are created and may not be removed as you say.
This would mostly occur if you used an O2 system to oxygenate your wort. This can get more oxygen into your beer then a stir plate starter did to your starter. Easily.
That said, folks who don't oxygenate their wort well would get the under attenuating effect you describe for sure because it will limit the growth phase and not enough daughter cells will be produced.
Re: This doesn't look good
For some more info, check out Kai's
Yeast Growth on Malt Sugar Experiment thread..
Interesting read...
http://braukaiser.com/blog/blog/2013/07 ... and-sugar/
Yeast Growth on Malt Sugar Experiment thread..
Interesting read...
http://braukaiser.com/blog/blog/2013/07 ... and-sugar/
Re: This doesn't look good
Hmm... something is wrong with that article.
See corn sugar is Dextrose, not Glucose.
Beer yeast don't' really like Glucose all that much, they have to split it using an enzyme called invertase into dextrose and other sugars in order to eat it. This takes more time and energy then just eating maltose or dextrose, which is what they like to eat. Which would explain the results of that experiment. Except that what we call corn sugar for brewing is not glucose.
If the experiment was done with actual dextrose, I would think that the yeast would eat it just fine. Except for one thing - dextrose doesn't contain all the nutrients that you get from DME/LME/mashed grains. So it would require yeast nutrients to keep the yeast happy. Because again once they run out of ANY nutrient needed for growth... they won't grow. They will just try to ferment because it's all they got left to do. So a mix of dextrose and maltose or dextrose with lots of added nutrients would work better then glucose.
See corn sugar is Dextrose, not Glucose.
Beer yeast don't' really like Glucose all that much, they have to split it using an enzyme called invertase into dextrose and other sugars in order to eat it. This takes more time and energy then just eating maltose or dextrose, which is what they like to eat. Which would explain the results of that experiment. Except that what we call corn sugar for brewing is not glucose.
If the experiment was done with actual dextrose, I would think that the yeast would eat it just fine. Except for one thing - dextrose doesn't contain all the nutrients that you get from DME/LME/mashed grains. So it would require yeast nutrients to keep the yeast happy. Because again once they run out of ANY nutrient needed for growth... they won't grow. They will just try to ferment because it's all they got left to do. So a mix of dextrose and maltose or dextrose with lots of added nutrients would work better then glucose.