Am i going to make my FG?

[Jsbeckton]

Made Jamils Oktoberfest about 2 and a half weeks ago, hit the OG and split a 1.5L starter between 2 carboys (10 gal batch), and stuck it in my keezer at 50F. Fermentation started within about 2 days with one Carboy going a bit stronger than the other, must not have split evenly.

After a week it was down to about 1.034 ( from an OG of about 1.056) and now a week and a half later it's sitting about 1.028 with a bubble every 10s or so. I had hoped to have it down to about 1.018 after two weeks and then do a rest to finish it out to about 1.014.

Being that it is behind I have tried shaking the Carboy up and raising the temp to 55F. I am worried that it is not going to make it. Any thoughts and what could the cause be for the somewhat slow fermentation. I would make a bigger starter next time for a 10g batch of lager but other than that I am not sure. I mashed at 149F so that can't be it either?

 

[daksin]

So, the first big issue is that you massively underpitched, which you know. In the future, use the Mr. Malty calculator at mrmalty.com. Don't forget to make sure you've marked that you're making a lager, when the yeast was made for viability, and whether or not you're using a stir plate.

Using that calculator, for 10 gallons of 1.056 lager, and imagining you have perfectly viable yeast (you didn't), and you're working on a stirplate which increases the density of cells that grow in your starter, you should have used 7L of starter.

I would let it go where it is for now and let it sit for a while. Keep rousing it and checking the gravity- when it gets to ~1.022 warm it up to 60F for a diacetyl rest, which should help it finish up. Then lager for a really really long time, as you've probably generated a lot of undesirables that will take some time to lager out. Try ~33F for at least 10 weeks.

 

[Jsbeckton]

So, the first big issue is that you massively underpitched, which you know. In the future, use the Mr. Malty calculator at mrmalty.com. Don't forget to make sure you've marked that you're making a lager, when the yeast was made for viability, and whether or not you're using a stir plate.

Using that calculator, for 10 gallons of 1.056 lager, and imagining you have perfectly viable yeast (you didn't), and you're working on a stirplate which increases the density of cells that grow in your starter, you should have used 7L of starter.

I would let it go where it is for now and let it sit for a while. Keep rousing it and checking the gravity- when it gets to ~1.022 warm it up to 60F for a diacetyl rest, which should help it finish up. Then lager for a really really long time, as you've probably generated a lot of undesirables that will take some time to lager out. Try ~33F for at least 10 weeks.

Hmm, I only calculated a 4L starter and was thinking I should have used about a 3L but yes it was well under. I think that the mr malty calculator is usually overkill actually. It says you need about 4L for an 1.065 ale with intermittent shaking but I have probably made 30 batches with about 1.5L starters over the last few years and have have never had a problem.

I can see a slow start from a low pitch but what puzzles me is why once it does get going and has the yeast count needed it seems to wimper out before the end?

 

[Yooper]

Hmm, I only calculated a 4L starter and was thinking I should have used about a 3L but yes it was well under. I think that the mr malty calculator is usually overkill actually. It says you need about 4L for an 1.065 ale with intermittent shaking but I have probably made 30 batches with about 1.5L starters over the last few years and have have never had a problem.

I can see a slow start from a low pitch but what puzzles me is why once it does get going and has the yeast count needed it seems to wimper out before the end?

Because the yeast only reproduced so much, and then are worn out.

To quote Dr. Phil on your "mrmalty calculator is overkill actually"- "How's that working for ya?"

Seriously, underpitching an ale doesn't give the best flavor or result, but it's not nearly as crucial as in a lager. Underpitching may mean some off-flavors, a higher than desired FG, and a long time to finish up. But in an ale, it's usually just fine. The problem is with a lager (which needs a LOT of yeast) and stressed yeast may create some yeast character that is undesired.

In any case, when you get down a few more points you can try doing a long-ish diacetyl rest and encourage it to finish up. That should also help to clean up excess diacetyl created as a result of the underpitching.

 

[Jsbeckton]

To quote Dr. Phil on your "mrmalty calculator is overkill actually"- "How's that working for ya?" .

I'd say good, I have won medels for lagers and ales pitching about 1/2 what mymalty estimates so I still contend it is overkill. I agree that this one was under but I am saying that it was under by about 2L maybe 3L, not 5L (only decided to double the batch on brew day)

Because the yeast only reproduced so much

If I have a 1L starter or a 10L starter, I start with the same number of cells at the time the starter is made so this doesn't really make sense that the yeast is tired from overproducing. As I understand it, the only difference is with a starter, the reproduction gets a "head start" at reproducing but it in no way means that cells have to reproduce less? So to me it seems to only be impacting the delay in fermentation begining which is a concern for bacteria but i can't connect it with high FG?

Am I missing something?

 

[Yooper]

I'd say good, I have won medels for lagers and ales pitching about 1/2 what mymalty estimates so I still contend it is overkill. I agree that this one was under but I am saying that it was under by about 2L maybe 3L, not 5L (only decided to double the batch on brew day)



If I have a 1L starter or a 10L starter, I start with the same number of cells at the time the starter is made so this doesn't really make sense that the yeast is tired from overproducing. As I understand it, the only difference is with a starter, the reproduction gets a "head start" at reproducing but it in no way means that cells have to reproduce less? So to me it seems to only be impacting the delay in fermentation begining which is a concern for bacteria but i can't connect it with high FG?

Am I missing something?

Not "tired" from reproduction, but instead "tired" from fermentation when they are unhealthy.
As an analogy, say you have 10 acres of grass. You hired 2 guys. They may finish the grass, but maybe not on your timetable or to your specification. If you had 10 guys, the job would be done quicker and with a lot more energy.

I hope that makes sense.

 

[duboman]

Not "tired" from reproduction, but instead "tired" from fermentation when they are unhealthy.
As an analogy, say you have 10 acres of grass. You hired 2 guys. They may finish the grass, but maybe not on your timetable or to your specification. If you had 10 guys, the job would be done quicker and with a lot more energy.

I hope that makes sense.

As a landscape contractor I will tell you your analogy is spot on! LOL!

To the Op, while the purpose of the starter is to grow the proper amount of cells, it's most important part is to grow healthy cells that are fully capable of getting the job done properly and in a timely manner

There are always people that say they never use a starter and the beer ferments fine, which may be true, but how much better would the beer be if it was fermented properly? This is why starters are highly recommended for all liquid yeast strains

 

[Jsbeckton]

Not "tired" from reproduction, but instead "tired" from fermentation when they are unhealthy.
As an analogy, say you have 10 acres of grass. You hired 2 guys. They may finish the grass, but maybe not on your timetable or to your specification. If you had 10 guys, the job would be done quicker and with a lot more energy.

I hope that makes sense.

Actually that is exactly why I am can't make sense of this. If I buy 1 tube of yeast you start with the same amount of yeast weather you make a 1L starter or a 10L starter. In your analogy I would say that my 2 guys (ok, lets make it one guy and one girl!) go at it until they have a family of 10 to do the work.

I have brewed with a starter that was made with the sediment in the bottom of a Bells bottle,...very little yeast that had to multiply and make the beer so this doesn't seem to make sense. A start is just a head start, not better yeast, no?

 

[Yooper]

A start is just a head start, not better yeast, no?

No. You will get more replication from the fewer starting cells (small starter or no starter), but the end result will not be the same total number of cells. So, with a proper sized starter, you'll end up with more cells and more healthy cells at that.

To go back to the lawnmower analogy, say I gave the two guys a headstart. They still would be exhausted and overworked, compared to the 10 guys.

That's a total oversimplification of course, but the issue goes back to reproduction and how many generations, and the stress environment of the fermentation.

There are lots of great resources on this- notably by Chris White and Jamil Zainasheff in their book "Yeast" as well as Jamil's website, mrmalty.com.

 

[Yooper]

If I buy 1 tube of yeast you start with the same amount of yeast weather you make a 1L starter or a 10L starter.

See, that's the flaw in this logic. There AREN'T as many cells in the 10L starter as in the 1L starter, when finished.

 

[Jsbeckton]

No. You will get more replication from the fewer starting cells (small starter or no starter), but the end result will not be the same total number of cells. So, with a proper sized starter, you'll end up with more cells and more healthy cells at that.

To go back to the lawnmower analogy, say I gave the two guys a headstart. They still would be exhausted and overworked, compared to the 10 guys.

That's a total oversimplification of course, but the issue goes back to reproduction and how many generations, and the stress environment of the fermentation.

There are lots of great resources on this- notably by Chris White and Jamil Zainasheff in their book "Yeast" as well as Jamil's website, mrmalty.com.

From How to Brew, page 86, Palmer says you need about 2/3 cup slurry for a lager. I had about 1/2" or so in my 2L stir plate flask which is about 4/3 cup, (just checked) so basically what he suggests for a 10 gal Batch is what I had with what I would even consider a small starter. If I had doubled that for a planned 10 gal batch I would have started with well over two cups with less than half of what mr malty suggests I need for a starter.

 

[SpeedYellow]

To the OP, I agree with you that Mr. Malty is somewhat overkill for lagers, but it looks like you only pitched about 30-40% of the suggested cells. I've found that to lead to long fermentation times, so next time bump it up to 50-60% and I think you'll find much quicker and more vigorous fermentation. Finishing fermentation in 10 days beats 21 days .

FWIW, I never saw poor attenuation when massively underpitching lagers, just slow fermentation. So I'm sure you'll make it, it'll just take 3-4 weeks total.

 

[midfielder5]

From How to Brew, page 86, Palmer says you need about 2/3 cup slurry for a lager. I had about 1/2" or so in my 2L stir plate flask which is about 4/3 cup.

Yes that rec seems low. I checked the book, which does say "at least" and then refers the reader to the chapter on yeast pitch rates for more.
In his chapter re lagers (pg 101) it says "about" 1/2 - 3/4 cup of slurry for an 1.050 OG lager. Your beer was a bit higher (1.056). So Palmer gives a bit of contrary info.
Anyways, good luck.
cheers,
Wendy

 

[Jsbeckton]

To the OP, I agree with you that Mr. Malty is somewhat overkill for lagers, but it looks like you only pitched about 30-40% of the suggested cells. I've found that to lead to long fermentation times, so next time bump it up to 50-60% and I think you'll find much quicker and more vigorous fermentation. Finishing fermentation in 10 days beats 21 days .

FWIW, I never saw poor attenuation when massively underpitching lagers, just slow fermentation. So I'm sure you'll make it, it'll just take 3-4 weeks total.

Yeah, I ended up doubling the batch at the last second but obviously didn't have time to double the starter. So I guess exactly what you said, longer fermentation time but there is no reason that should prevent it from reaching target FG.

 

[Jsbeckton]

***update***

Checked again yesterday and It was at 1.018 with it still trickling away. Raised 10F for a rest even though I didn't detect any off flavors. Guess even with the low pitch the only impact was fermentation time. Think I have a great Oktoberfest under way.

 

[Jsbeckton]

Finished at 1.014

Perfect!