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corpsman619

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So when you have made a yeast starter and put it in the fridge and you want to use it on brew day. Are you supposed to decant the extra beer while It is cold (so that It is easier to keep the yeast from moving around too much) or after you have let it warm up?

Follow up questions: Does it make a difference if you just pitch the whole thing ( in my case 1.5 liters) ? I have heard that it can add unwanted flavors?

As always, thanks in advance for all of your feedback.
 
If you're taking it out on brew day to let it warm up to pitching temp, I'd just wait until you're ready to pitch to decant. Less exposure that way. The yeast will remain on the bottom, even if the starter warms up
 
I always pour the whole thing, liquid and all. That's what the guy at my LHBS said he does and he's been brewing for 20 years. It's worked for me for my last 4 beers that I've used a starter.
 
1.5 liters added to a 20 liter (5 gallon) batch is about 7%. If the starter was on a stir plate at 70°F or warmer there may be some noticeable difference in flavor. When I used yeast from a starter I typically propagate on a stir plate at about 70°F, do a cell count after propagation has completed, refrigerate, decant, and then pitch cold or at the temperature of fermentation.
 
The other day I made a yeast starter and chilled it after its growth stage. I decanted what I could off (I might have left about 1/2 to 1 cup of starter wort) and left the yeast slurry out to warm up to pitching temperatures. While brewing my yeast woke up and started fermenting the remaining sugars in the wort I left in the slurry and the krausen grow so much that I had to place it back in the fridge to avoid making a big mess in the kitchen. Everything worked out fine but my point with this story is that if you grow your yeast for about 24hrs (the yeast have pretty much completed the growth phase by this time) then chill them you should decant the wort off the yeast while it is still cold otherwise you may have a a giant krausen prior to pitching due to the reactivation of the yeast and the available sugars in the wort. Unless of course you make a starter a week in advance and let the yeast complete the process of fermentation so there aren't any remaining sugars for the yeast to convert once you pull it out of the fridge. If that is the case then you will still want to decant the spent wort off the yeast otherwise it may add unwanted flavors to your finished product. If you want to just pitch the whole starter into your fermentor then I would recommend making a starter with the same malt profile as you have planned for your beer so the flavors of the starter are closer to the flavors of your beer.
 
Since I pitch my starter at the same temp I want to ferment, and since I'd prefer not to have as much starter wort in my finished beer, and since I try to pitch actively fermenting yeast, I use this process: First, I make the starter the size needed for the amount and gravity of beer I'm making, using canned starter wort. mrmalty.com is fine for this, as is the starter tab in BeerSmith. I start it 4 days before brew day. I put it on a stir plate in my temp-controlled fridge for 24-36 hours at 75 degrees. Then I stop the stirplate, and drop the temp to 40 for 2 days, so the yeast drops out quickly. The day before brew day I raise the temp to fermentation temp, and put a small can of starter wort in the fridge as well so it will be the same temp. The morning of brew day, I decant the starter, and pitch the small can of starter wort into the flask. By the time I pitch, I have actively fermenting yeast, and have been pleased with the cleanness of the flavors I getting from this process.

I'd love to say exactly why I do it this way, and cite specific scientific studies or brewing resources, but after almost 18 years of brewing, so much of what I do is influenced by the mass amounts of info I've picked up along the way, so what I do is either Zen or Voodoo.
 
While brewing my yeast woke up and started fermenting the remaining sugars in the wort I left in the slurry and the krausen grow so much that I had to place it back in the fridge to avoid making a big mess in the kitchen.

I'm wondering if you might have chilled too soon. There should not have been any sugars left for the yeast to rouse and start fermenting. Maybe give your starters another day before you chill?
 
I'm wondering if you might have chilled too soon. There should not have been any sugars left for the yeast to rouse and start fermenting. Maybe give your starters another day before you chill?
The exact same thing happened to me today! I took out my starter which had fermented for about 24 hours (no signs of fermentation, chilled for 24 hours) brought it to room temp and when I was about to pitch I started to shake it to break up the cake and it started spraying!! I was like WTF! I pitched it with big chunks and now I am not sure whether or not it will affect my fermentation.
 
Well, that would be CO2 in suspension, and when you shake it you create nucleation sites that allow the CO2 to come out of suspension quickly. A similar experiment to see this in action: shake up a warm can of Bud and pop the top.
 
corpsman619 said:
The exact same thing happened to me today! I took out my starter which had fermented for about 24 hours (no signs of fermentation, chilled for 24 hours) brought it to room temp and when I was about to pitch I started to shake it to break up the cake and it started spraying!! I was like WTF! I pitched it with big chunks and now I am not sure whether or not it will affect my fermentation.

Should be just fine. So you know the yeast was alive and working. Big chunks vs. a nice consistency from swirling - shouldn't change anything. It was just more compact b/c it had been chilled. The yeast is doing it's thing and will really come alive when it hits your wort.

FWIW - I typically do a 1.5L starter and let it go for 24-36 hrs at ~ 70 deg., shaking often, and just pitch the whole thing into my wort (shaking right up until pitching time). Always good clean results. Unless my starter gets above 75 if room temp is warmer than usual, I never decant, and haven't experienced any off flavors from such a small amount of starter wort. I'd be way more worried if there were no signs of fermentation at all during the initial starter time or after warm up.
 
DWhitwell said:
I'm wondering if you might have chilled too soon. There should not have been any sugars left for the yeast to rouse and start fermenting. Maybe give your starters another day before you chill?

I let it grow for about 26-28 hrs. All the growth should have occurred by that point and then the yeast start converting the sugars into alcohol. There should still be plenty of sugars since I'm chilling them after growth before they have a chance to finish the starter wort. At least this is my thinking on the matter.
 
I let it grow for about 26-28 hrs. All the growth should have occurred by that point and then the yeast start converting the sugars into alcohol. There should still be plenty of sugars since I'm chilling them after growth before they have a chance to finish the starter wort. At least this is my thinking on the matter.

I'm not sure why you'd chill a starter before they finished. If I understand, the point of making a starter it is to grow more yeast and then let the yeast complete their full cycle and go dormant so they have enough glycogen reserves to start up again. Is there something I'm missing here?
 
Yeah I believe somewhere in the thread I mentioned I wad under the impression that it had fully fermented out. Next time I will let it go a few days instead of 24 hours. But there were no visible signs of fermentation anymore.
 
Yeah I believe somewhere in the thread I mentioned I wad under the impression that it had fully fermented out. Next time I will let it go a few days instead of 24 hours. But there were no visible signs of fermentation anymore.

Sorry, I missed that! I thought you did it on purpose!
 
DWhitwell said:
I'm not sure why you'd chill a starter before they finished. If I understand, the point of making a starter it is to grow more yeast and then let the yeast complete their full cycle and go dormant so they have enough glycogen reserves to start up again. Is there something I'm missing here?

Now that you mentioned it I see where I was getting my thoughts crossed. I wanted to pitch at high krausen but it was a 3L starter and I didn't want to pitch that much wort so I chilled it. Well I guess I should have let it finish then decanted it. Regardless of this, those bad boys handled the chill and warm up without their glycogen reserves. I have had to change from an airlock to a blow off tube and have had great fermentation since. I was a little worried that not all the yeast would settle out while chilling them so I chilled the decanted wort and there were a few cells in there. I pitched those cells into my small beer I am experimenting with; I collected the sparge water runnings still in my MLT after collecting my wort and boiled. Hey DWhitwell let me ask you this: do you wash your yeast? And if so do you wash your yeast the day of brew day to repitch that day or do you throw your washes yeast into another starter? I have read that it is fine to repitch washed yeast day of. My thinking is that they are dormant with their glycogen reserves and will become active once re-introduced to fermentable sugars.
 
Now that you mentioned it I see where I was getting my thoughts crossed. I wanted to pitch at high krausen but it was a 3L starter and I didn't want to pitch that much wort so I chilled it. Well I guess I should have let it finish then decanted it. Regardless of this, those bad boys handled the chill and warm up without their glycogen reserves. I have had to change from an airlock to a blow off tube and have had great fermentation since. I was a little worried that not all the yeast would settle out while chilling them so I chilled the decanted wort and there were a few cells in there. I pitched those cells into my small beer I am experimenting with; I collected the sparge water runnings still in my MLT after collecting my wort and boiled. Hey DWhitwell let me ask you this: do you wash your yeast? And if so do you wash your yeast the day of brew day to repitch that day or do you throw your washes yeast into another starter? I have read that it is fine to repitch washed yeast day of. My thinking is that they are dormant with their glycogen reserves and will become active once re-introduced to fermentable sugars.

I don't rinse and reuse yeast, mostly because on bottling day, I feel like I have enough to deal with, and, frankly, I don't trust myself enough to do it right. I have just started slanting yeast, though, and think that I can be okay with the requirements. I do it mostly to save $ and because it's something I can do that is brew related that isn't making beer. That might sound odd, but there are lots of aspects of the hobby you can delve into, and that is one I'm playing with now that I'm done building my brewstand.

As to your question: If you had a small enough amount of yeast you were reusing, you would probably want to make a starter, but if you had a large enough pitch of slurry, I don't think a starter would be necessary. Maybe, if I were wanting to pitch roused yeast, I might feed the slurry on brewday a few hours before I pitched (like when I started heating my strikewater), but honestly I don't know how important it is to pitch active yeast. Maybe it's just voodoo!
 
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