Primary Fermentation Very Slow

[BrewNoob78]

Hey Everyone,

I am new to the forum and have been brewing with a group of my friends for the last 3 years. Needless to say this year was our first year we invested in new equipment (Big Mouth Fermenters, Thermo Blankets, Temp Monitor/Regulators) as we were just using an old dusty coat closet before with nothing but our normal house temp conditions and no monitoring of actual wort temp in place while fermenting.

So our first two beers this year lacked very much in that the fermentation stalled out. I am chalking this up to strictly poor aeration as the first batch was barely rocked and pitched and the second was aerated for 2 minutes using a aquarium pump and micron stone with an inline filter that looked to actually inhibit the pump from pushing out enough air. We found this to be the case on our now third batch of the year, so we removed the inline filter and after thorough sanitation ran the micron stone in the beer for 20 minutes and aeration was producing a nice foam layer on top (maybe an inch or two high). This showed me that it made a definite difference. Now onto the actual issue I have...

Obi Ron (extract kit)

.5 lbs Bairds Light Carastan Malt (Specialty Grains)
3.15 lbs Wheat Malt Syrup
1 lb Golden Light DME
3.15 lbs Wheat Malt Syrup (10 min late addition)

1oz Hersbrucker (60 min)
1oz Czech SAAZ (20 min)
1oz Czech SAAZ (10 min)
1oz Centennial (Dry Hop)

Steep 160 - 30 mins
Boil - 3.15 Whe Malt Syrup and 1lb DME. Add hops and final malt at intervals listed above.

Yeast = Cali V Ale = used 1L Starter (Fast Pitch) for 5Gal batch prepped 16+ hours in advance.

Wort pitch temp - 68 degrees
Primary ferm temp - 68 degrees
O.G - 1.059

Fermentation started within 12 hours at 68 degrees. Constant bubble for first day. Then bubble schedule (took readings every 4 hours):

Day 2 - 4-5 secs apart
Day 3 - 7-8 secs apart
Day 4 - 7-8 during the day then fell at night to about 13 secs apart
Day 5 - 17-20 secs, kicked temp up 1 degree (69) 4 hours later back to 13 secs apart
Day 6 - 26 secs apart - first Grav reading 1.034
Day 7 - 17-18 secs apart then dropped off in the evening to 27 secs apart
Day 8 - 23-30 secs apart
Day 9 (today) - 33 secs apart as of this post.

Took another Grav reading and down to 1.031, so certainly still fermenting compared to my day 6 reading, however target abv for this beer is 5.4% which would mean I would have to hit 1.018 F.G. to get that.

Its day 9 already and I am not sure what went wrong, but most posts I see fermentation drops into the Ten Ten range seem to happen within first 5 days. I am in Day 9 and still long way to go. Do I just assume I will not hit the target? Any suggestions on what I may be doing wrong? Maybe not enough oxygen? Not sure why its moving as slow as it is. I will just let it be until at least this Saturday which makes week 2 in the primary, but I dont have hopes that 5 days at the slow ferment will net me 1.018 FG.

Thanks for any info.

 

[IslandLizard]

Generally, slow fermentations are better than fast ones. Alas, this does seem a little slow going.
Are you taking the gravity readings with a hydrometer? Or refractometer?

How old do you think that yeast pack was? There's a manufacturing date on the pack. Is there a chance it was old or not in optimal condition? Possibly frozen in transit? It may have contained far fewer vital cells than the 100 billion of a fresh pack.

A liter starter can be a bit skimpy in a 5 gallon 1.059 ale if the yeast is not quite fresh. 2 liters is generally recommended, plus it allows you to save some out to make a starter from for your next batch, and again, and again...

Use a yeast calculator such as HomebrewDad's to calculate needed starter size more accurately. The age and condition of the yeast pack play a large role, so apart from the date, her overall health due to her history may need to be taken into account.

 

[IslandLizard]

Have you checked your actual ferm temps (the temp of the beer) with an accurate thermometer? Is the fermenter inside a ferm chamber (temp controlled fridge)? Maybe it is, or gets too cold in there.

 

[BrewNoob78]

Generally, slow fermentations are better than fast ones. Alas, this does seem a little slow going.
Are you taking the gravity readings with a hydrometer? Or refractometer?

How old do you think that yeast pack was? There's a manufacturing date on the pack. Is there a chance it was old or not in optimal condition? Possibly frozen in transit? It may have contained far fewer vital cells than the 100 billion of a fresh pack.

A liter starter can be a bit skimpy in a 5 gallon 1.059 ale if the yeast is not quite fresh. 2 liters is generally recommended, plus it allows you to save some out to make a starter from for your next batch, and again, and again...

Use a yeast calculator such as HomebrewDad's to calculate needed starter size more accurately. The age and condition of the yeast pack play a large role, so apart from the date, her overall health due to her history may need to be taken into account.

Hi thanks for the quick response. I am checking the gravity with a refrac and I check calibration every time with distilled water. I saw some require calibration solution but they really dont tell you which ones. Instructions on mine state calibrate with distilled so thats what we used.

Looking now at the yeast pack it was manufactured Dec 9, 2018 so definitely a couple months old. Best by day is June 7th 2019. Not sure how BB dates work with yeast as I would assume I probably wont get the full cell count of a 2-3 month old yeast. Maybe not enough of a starter then as you suggested based on date of yeast? The yeast pack itself says only needs 1 L starter for 5 gal batch but maybe thats White Labs estimation for a full healthy yeast pack?

 

[BrewNoob78]

Have you checked your actual ferm temps (the temp of the beer) with an accurate thermometer? Is the fermenter inside a ferm chamber (temp controlled fridge)? Maybe it is, or gets too cold in there.

No I have an LCD thermometer from Northern Brewer on the glass carboy and use a probe that is submergged in the wort connected to a temp controller hooked to a Thermo heat blanket. The probe is registering the same as the LCD temp gauge so I would assume the submerged probe is accurate.

 

[IslandLizard]

I am checking the gravity with a refrac and I check calibration every time with distilled water. I saw some require calibration solution but they really dont tell you which ones. Instructions on mine state calibrate with distilled so thats what we used.

Refractometer readings are not accurate once alcohol is present, they read too high, especially toward the end of fermentation, as there is more alcohol.

You need to use a correction formula (e.g. Sean Terrill's) that requires the OG and your current SG reading to determine the actual SG.

Distilled water is fine for the bottom line, 1.000 calibration. Nothing else is needed. Mine has stayed on 1.000 for 6 years, I rarely check that anymore.

 

[BrewNoob78]

Hi thanks for the quick response. I am checking the gravity with a refrac and I check calibration every time with distilled water. I saw some require calibration solution but they really dont tell you which ones. Instructions on mine state calibrate with distilled so thats what we used.

Looking now at the yeast pack it was manufactured Dec 9, 2018 so definitely a couple months old. Best by day is June 7th 2019. Not sure how BB dates work with yeast as I would assume I probably wont get the full cell count of a 2-3 month old yeast. Maybe not enough of a starter then as you suggested based on date of yeast? The yeast pack itself says only needs 1 L starter for 5 gal batch but maybe thats White Labs estimation for a full healthy yeast pack?

So in addition would just building a bigger starter still push 3 month old yeast to peak cell replication or would I also need to add more yeast or maybe yeast nutrient. I use the Fast Pitch cans and they dont call for adding nutrient.

 

[IslandLizard]

No I have an LCD thermometer from Northern Brewer on the glass carboy and use a probe that is submergged in the wort connected to a temp controller hooked to a Thermo heat blanket. The probe is registering the same as the LCD temp gauge so I would assume the submerged probe is accurate.

When you get a more accurate thermometer you may be surprised how close they can be. Or how far off...

I used a $16 electronic thermometer (Amazon) for years, until I finally got too impatient waiting for stable readouts, and splurged on a Thermapen Mk4. Never looked back.

 

[bracconiere]

if your using a refractometer, you need to use a calc to get actual FG...

edit: i was beat to it while trying to figure what the actual FG was...

 

[IslandLizard]

Looking now at the yeast pack it was manufactured Dec 9, 2018 so definitely a couple months old. Best by day is June 7th 2019. Not sure how BB dates work with yeast as I would assume I probably wont get the full cell count of a 2-3 month old yeast. Maybe not enough of a starter then as you suggested based on date of yeast? The yeast pack itself says only needs 1 L starter for 5 gal batch but maybe thats White Labs estimation for a full healthy yeast pack?

Nah, you did fine.
White Labs' Pure Pitch packs remain close to their 100% viability for the first 3 months, stored in the fridge. It drops off a bit more rapidly over months 4-6. Read up on that on their site. That's quite an achievement!
Yeast calculators haven't been reprogrammed for that, so you'll get a much more conservative view.

How old is too old? I just revived 2 WLP Pure Pitch packs of Lager yeast packaged late 2016 (!), stored in fridge since. It took a week to get them going, starting out with 375 ml of 1.017 starter wort. They smell bready, as they should. They need one more step up, I'll brew with them next week, saving some out for another, and another...

 

[IslandLizard]

So in addition would just building a bigger starter still push 3 month old yeast to peak cell replication or would I also need to add more yeast or maybe yeast nutrient. I use the Fast Pitch cans and they dont call for adding nutrient.

You need to use a yeast calculator (e.g., HomebrewDad's, linked before) to see how to get to your pitchable cell count. And overbuild it somewhat, so you can save some out (yeast ranching) for a next batch, and a next...

Generally only a small amount of yeast is needed to grow lots of cells, but it may need to be done in separate steps. There are some edge parameters, you'll see.

I add some homemade yeast nutrient mix that also includes a small amount of Zinc (Sulfate). Most other nutrients are in the wort. Not sure of if the Fast Pitch needs any additional nutrients. I would doubt it, except for the Zinc that is.

 

[McKnuckle]

Don’t ignore the two posts telling you that you cannot test gravity with a refractometer once alcohol is present. Your beer is done. And likely the other ones, too. You can only measure gravity “as is” with a hydrometer once fermentation is underway.

 

[BrewNoob78]

if your using a refractometer, you need to use a calc to get actual FG...

edit: i was beat to it while trying to figure what the actual FG was...

Yea. I typically use the brewers best friend calc.

https://www.brewersfriend.com/abv-calculator/

You need to use a yeast calculator (e.g., HomebrewDad's, linked before) to see how to get to your pitchable cell count. And overbuild it somewhat, so you can save some out (yeast ranching) for a next batch, and a next...

Generally only a small amount of yeast is needed to grow lots of cells, but it may need to be done in separate steps. There are some edge parameters, you'll see.

I add some homemade yeast nutrient mix that also includes a small amount of Zinc (Sulfate). Most other nutrients are in the wort. Not sure of if the Fast Pitch needs any additional nutrients. I would doubt it, except for the Zinc that is.

Thanks for all the info. I have been looking at the yeast calculator you linked and it calls for a 1.5L starter based on yeast age, cell count, etc. and we only used 1L. Could be a lead......so I will pay more attention to that moving forward as this was not on my noob radar yet. I know as long as I am getting drops not to move it secondary and to let the yeast continue to work, so heres to hoping shes just churning slow. Appreciate the feedback and we are learning something new every session and its still fun so we will keep brewing. We do a party every year for it and have people come tast

Refractometer readings are not accurate once alcohol is present, they read too high, especially toward the end of fermentation, as there is more alcohol.

You need to use a correction formula (e.g. Sean Terrill's) that requires the OG and your current SG reading to determine the actual SG.

Distilled water is fine for the bottom line, 1.000 calibration. Nothing else is needed. Mine has stayed on 1.000 for 6 years, I rarely check that anymore.

You guys have resolved my issue and wiped away all doubt of me continuing to pursue this hobby. Checking with the refrac after alcohol has been introduced has been our issue now for the last year to date. I pulled out and dusted off the Hydrometer as we put it away thinking the Refrac was our new latest and greatest tool to use for checking ABV moving forward. Pulled a sample from my batch in secondary and my batch in primary using the Hydrometer and both my gravity checks showed significant number differences. Almost like the refrac is a hundredth off. Of course I wont bet on that and will still take my Hydrometer readings moving forward.

Thanks for pointing me in the right direction me and my partners feel much better about not being brewer failures.

Sorry for the delayed response. I am only allowed to post 5 times in a given 24 hour period so had to wait to post this. I did the test right after you all mentioned the refrac being a potential root cause of my failed data points.

Obi Ron

Refrac: 1.030
Hydrometer reading: 1.020 = 5% abv after calculations

Choc Stout

Refrac: 1.032
Hydrometer: 1.022 = 4.68% abv after final calc

 

[McKnuckle]

Hydrometers might waste wort/beer, but I personally think that refractometers suck, sorry if that offends someone. I have one of course, and it’s either unusable (after ferm) or inaccurate (tiny unrepresentative sample; “correction factor” that changes with every brew etc.).

I now just plan my recipes to include a 1 cup loss for a proper OG hydrometer sample. And for pre-boil I pull a cup of stirred wort and chill it to 80° or so. It’s just more reliable.

Rant off. As you were! [emoji4]