Stuck Fermentation For The Third Time!

[musselmanbrewing]

I was hoping someone could shed some light on my dilemma, and sorry in advance if this has been answered, but I couldn’t find one directly.

I’ve brewed 3, 15gal batches - vanilla brown ale, honey cream, and a black IPA respectively. The first batch I used 3 vials of WLP001 - no starter (I regret that decision). The fermentation started with an OG of 1.066 and an FG of 1.036 which was short of the 1.016 which I had hoped for. I said ‘oops’ and kegged it.

On the second batch (honey cream) I washed and reused yeast from the first batch AND started to regulate the temperature of the fermenter (set to ~69F). Again my fermentation didn’t go as well as expected with an OG of 1.061 and an FG of 1.030 - I wanted an FG of 1.010. I was more irritated but kegged it again anyway.

The third batch (black IPA) I again washed and reused the yeast from the honey cream batch and made a 5L starter (in 3 stages). I kept the fermenter around 68-69F again and still fermentation fell short. OG 1.063 and FG of 1.034 (wanted 1.-14 ish). This time I wanted to do something about it! So I bought a smack pack of Wyeast 1056, made a 2.5L starter with it (in 2 stages) and pitched it into the black IPA in hopes that it would complete the fermentation. Its been 3 days and no movement in gravity.

My question is… WHAT IS GOING ON?? I used an oxygen stone and pure oxygen for about 60 ish seconds at 3 Lpm as it is being pumped into the primary, I used a starter, and I keep the temperature around 68-69 F. Other than re-using possibly crap yeast from the first batch, what could be wrong. And could me pitching a second volume of yeast to the last batch just be taking a bit longer to complete the fermentation? Please let me know what I missed in order for you guys to help me out. I’ve done a bunch of research and I have no idea whats up.

Thanks for the help in advance!

 

[Thunder_Chicken]

You never mentioned how long you waited to get to FG. How long did you let these sit in primary?

 

[lebucheron]

Is this all grain or extract? Is your hydrometer calibrated ok?

 

[LLBeanJ]

Are you checking FG with a hydrometer?

 

[musselmanbrewing]

Thanks guys. Ok, for each the primary was about 10 days before i used a hydrometer (calibrated) to measure the FG. And I’m using all grain.

 

[musselmanbrewing]

Oh, my fermentors are plastic conicals, so I take measurements every few days. I seemed to complete fermentation in about 4 days, but I let it sit for about a week more, but nothing.

 

[Thunder_Chicken]

How are your mash temperatures? If you're mashing high you might have a lot of unfermentables. Is your thermometer calibrated?

 

[musselmanbrewing]

For the brown ale i mashed around 156, the cream ale 150, and the IPA at 150 as well. I made sure the thermometers in my kettles were calibrated too. This is blowing my mind!! ha I must be missing something yeah?

 

[Thunder_Chicken]

Have you brewed anything similar lately with a different yeast?

It sounds like your yeast is bad. What made you decide to reuse yeast that left underattenuated beer in the first place? What made you think your 2nd and 3rd batches would fare any better?

 

[musselmanbrewing]

Ah yes… in hind sight… bad idea using crappy, possibly mutated yeast after the first batch. You may be right about the fact that it was just no good from the beginning. I’ve already marked the first two batches up as losses, so this third batch (still in the fermenter), I’ve added a new yeast strain to, and a 2.5L starter. Do you think I could essentially ‘jump-start’ the fermentation back to life to reach my desired FG? I’ve already pitched it 3 days ago, but no activity. Thoughts? And no recent brews yet, I kinda wanted to get an idea of what was going on before I started another brew.

 

[Thunder_Chicken]

It sounds like the rest of your process is solid, so pitching a new yeast would be a worthwhile experiment to try to save the last batch. If it works and you hit FG, you know it was a yeast issue and can move on with your brewing.

Only other thing would be if you had some common grain in all three batches that was really high in unfermentables or too low in diastatic power (lots of adjuncts and not enough 2- or 6-row to convert starches). Maybe not likely, but possible. If your new yeast pitch doesn't work, you might try some amylase enzyme to see if that gets you fermenting again, but AE can also convert ALL your starches to sugars so it might leave you very dry. I would consider that to be a last resort option.

Under no circumstances should you reuse the current yeast cake, irregardless of whether the newly pitched yeast works or not. Having a good and a bad strain duking it out in your beer is not an ideal ferment. Dump it, nuke your fermenter from orbit with a hot Starsan bomb and let it soak for a few days, and start fresh with everything including yeast.

 

[Thunder_Chicken]

If the new yeast isn't doing anything within a few more days, what you might consider would be pulling a fair sized (1-2 qt) sample from your fermenter and try AE in that. It needs to be big enough that you can get good gravity readings. If things start moving after the AE addition, then you'll at least know the source of your underattenuation and can start looking at your grain bill and mash for some solutions. You can then decide whether you want to add AE to the whole batch, or chalk it up as a final malty experiment and start a new batch.

 

[musselmanbrewing]

Thanks for all the help! I’ll give it a few more days and see if it starts to ferment, and if not, I’ll try the AE on a small batch and see what happens!

 

[Thunder_Chicken]

Let us know how it works out. If you try AE, you'll only need to use 1/8th of a teaspoon or less for about 2 quarts. If you don't already have some you should be able to get it at your LHBS; it's pretty cheap.