Did I underpitch?

[ParanoidAndroid]

Made an imperial pumpkin ale.

OG was 1.086.

Used 1 vial White Labs London Ale.

I made a 1.3 Liter Starter (130 gr DME/1.3 Liter Water) with a stir plate. Stirred 24 hours, then cold crashed overnight to get the yeast to the bottom. This is the size Mr. Malty recommended. However I see now where it said "#vials or packs needed with starter" is 3. Does that mean I should have bought 3 vials and STILL made a starter?

I just pitched this morning, so I can go get another vial if needed.

This is my first imperial and first time using a starter so I'm needing a little help.

I attached what the starter looked like this morning after the cold crash. I figured more yeast would be available than that, or is that what it should look like?

 

[jdauria]

Yes, you under pitched. Looking at Mr. Malty, even if the yeast was produced today, you would need two vials in a 1 liter starter. And White Labs vials have "best buy" date. so you need to go back four months from the date on the vial to get the production date. Do you know how old the yeast was?

Using the calculator at yeastcalc.co and making some assumptions:
A 5 gallon 1.086 beer needs 391 million yeast cells.

A 1.3 Liter starter with 130 grams = 1.035 starter yeast.

Estimating that the yeast was recent, using 8/13 as the date means it will have 83.7 million yeast cells.

So the 1.3 Liter starter at 1.035 with the 83.7 million yeast cells added will produce 265 million cells, so you were 126 million short.

So adding 1 more vial depending on freshness will give you another 80-90 million cells, still putting you 30-40 million short. This does not factor in any yeast reproduction in the fermenter though.

So you can add another vial and a half, or just add 1 more vial, and just let the beer ferment longer then normal. The yeast will do it's job, but just at a slower pace and hopefully get you close to your final gravity.

One other thing, personally, I let my starters go at least 2 days before cold crashing. Not sure if 24 hours is enough time to let the yeast fully do their thing.

What you could have done before you pitched, and that yeastcalc.co site is good for this, is pour off the wort in the starter leaving the yeast behind, then add fresh starter wort to build up the yeast. A second 1.3 Liter starter would have gotten you close to the optimal pitching rate.

 

[ParanoidAndroid]

Dang....I thought the purpose of a starter was to avoid having to buy so many vials. Seems like sometimes it'd be just easier to buy two or three vials than having to worry about measuring dme, water, boiling, disinfecting the flask, stepping up a starter after first one is finished, cold crashing, avoiding fruit flies, decanting, etc., etc. Seems like a lot can go wrong with a starter, just like brewing.

Thanks for the help. Ill stop by the brewshop today and pick up another vial.

I believe the best by date is oct 30/31 2014.

I decanted the flask before pitching. So what your saying is to decant the Starter Wort off the yeast, then add another 1.3 Liter/130 gram DME solution on top of the yeat left in the flask?

 

[flars]

Mrmalty recommends multiple vials of yeast because the calculator does not have the capability to calculate stepped starters.

These two calculators have the capability of stepped starters.
http://www.brewersfriend.com/yeast-pitch-rate-and-starter-calculator/
http://www.yeastcalc.co/yeast-pitch-rate-and-starter-calculator

 

[ParanoidAndroid]

Just working with Brewers friend here for future use, while inputting my currently mentioned brew.....

My inputs:

Wort Grav: 1.086
Wort Volume: 5.25 gal
Probrewer 1.0 (High grav)
Liquid Yeast
1 vial
Manf Date: 6/30/14 (mentioned BBD of Oct 30, 2014...so subtract 4 months)

This gives me:

55% Viability
55 Billion Cells
Target Pitch Rate: 411 Billion
Difference: -356 Billion

Doing a Starter:

Step 1:
1.3 Liter (just bc thats what I did the first time)
1.036 Gravity
Stirplate
Ending Cell Count : 242 Billion
Doesn't meet requirements so another step needed

Step 2:
1.4 Liter (Smallest I can do while hitting preferred rate)
1.036 gravity
Ending Cell Count : 415 Billion
Meets Requirements

That's the way I should have went about it (assuming I am doing this right).

However I didnt do the second step and went ahead and pitched. So if I do a straight pitch of a second vial (55 billion count) with the same date, that will still leave me 114 Billion Cells short.

Anything wrong with being short that many cells? Just leave it in primary longer?

Geez, just when I thought I had a basic grasp on water chemistry, I have to learn stepping starters real quick like. Knowledge of this hobby is never ending.

In the future, Ill do a 2 step starter.

 

[flars]

This is where I will say that I hope all works out.

The beer may finish just fine. The yeast may have been stressed to the point they will throw some off flavors. Off flavors, if it does happen, may or may not have a noticeable impact on the beer. The beer may stall at 1.020 or higher.

It is not an exact science. All we can do is try our best and hope an unseen variable doesn't screw it up. This is where having great patience comes into play. Plan to give it longer time in the primary than you were originally thinking.

Your beer will be benefited by being kept on the yeast cake. Don't plan a secondary.

Your calculations for stepping up a starter look good.

 

[rekoob]

you could use a larger starter.

 

[jdauria]

Just to correct my earlier post, I typed million several times while my brain was thinking billion. Oops!

 

[ParanoidAndroid]

Just to correct my earlier post, I typed million several times while my brain was thinking billion. Oops!

Ha, was wondering about that earlier.

Any harm in pitching a new vial ~10 hours after pitching a 1.3 L starter?

 

[jdauria]

Dang....I thought the purpose of a starter was to avoid having to buy so many vials....

I decanted the flask before pitching. So what your saying is to decant the Starter Wort off the yeast, then add another 1.3 Liter/130 gram DME solution on top of the yeat left in the flask?

Normally yes, with a starter with a stir plate, you only need to use 1 vial, for normal gravity beers, but at 1.086, that's a big beer that needs more.

And yes, decanting the starter wort of the yeast and adding a new DME solution on top is a way to build the yeast more...a stepped starter. As flars posted, there are a few sites that will do a calculation for you for stepped starters.

 

[ParanoidAndroid]

I had my wife stop by the LHBS to get another vial, but after reading several threads it seemed too risky to throw it in there. It was fermenting vigorously when I got home at 5pm (pitched at 630am). Even more this morning. I have a blow off tube going to a gallon glass jar with Starsan in it and the starsan was bubbling out of the top. 2-3 bubbles of air per second.

So I am leaving it be, hoping for the best, and will take the advice given here for my next batch. Thanks for the help guys.

On another note I should have read up more on starters beforehand and just went ahead and got the 5 Liter Flask and an appropriate sized stir plate instead of the StirStarter and 2L flask.