Slow Fermentation Advise Needed

I brewed a Belgian strong ale on July 7 and had an OG of 1.090. I had some issues with my yeast starter and wasn't able to pitch until the following day, July 8. I also fear that I under pitched due to my issues. I did not aerate the wort at the time of pitching. My bad. I had a very active fermentation for the first 4-5 days then things slowed down. Fermentation has been a constant 66F. I have taken a few samples and here are the results:

July 8 - 1.090 OG
July 11 - 1.064
July 14 - 1.058
July 18 - 1.052

Looking for a FG of 1.018

Now, the fermentation has been slow and I'm looking for some advise. Is a slow fermentation like I am experiencing normal? Is there anything I should do, other than wait it out? Perhaps aerate now? Pitch more yeast?

Cheers!

1.090 is a big beer. It sounds like you under-pitched, but it also takes a long while to reach those high alcohol levels -- yeast get drunk too.

My advice for now is to wait at least a few days to see if the gravity keeps dropping or not. If it seems stuck, try swirling the fermenter a bit to rouse the yeast.

If it really gets stuck, there are numerous options - like getting more of the same yeast, building up a starter, and pitching when the starter has been stepped up a couple times and is at high krausen.

Or you can get some dry champagne yeast like ec-1118, rehydrate it, and start building a starter by feeding it samples of your beer - step it up a few times and pitch that.

But i think that it's too early to say that you are in trouble.

i wouldn't use champagne yeast. champagne yeast can't ferment complex sugars like maltose. if you're still at 1.052, you still have a lot of maltose in there. i would go with either your original yeast strain (stepped up in a starter, pitched at high krausen) or a yeast known to restart stuck fermentation like 3711 or 099 (also stepped up in a starter and pitched at high krausen).

sweetcell said:

i wouldn't use champagne yeast. champagne yeast can't ferment complex sugars like maltose. if you're still at 1.052, you still have a lot of maltose in there. i would go with either your original yeast strain (stepped up in a starter, pitched at high krausen) or a yeast known to restart stuck fermentation like 3711 or 099 (also stepped up in a starter and pitched at high krausen).

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EC-1118 has been studied extensively by yeast geneticists. From what i can glean, it appears that it carries the MAL11 and MAL13 genes required for maltose assimilation, but they are not necessarily expressed - in fact, suppressed by the presence of glucose.

Thus, just dumping it in dry should not work, but gradually building a starter ought to work.

Sounds like more research is warranted.

Or just use french saison yeast. They say that will chew through anything.

OK guys, thanks for the advise. I'll sit back and wait it out, take another reading in 4 days or so and take it from there.

Does a REALLY slow fermentation have any bad side effects? Let's assume it continues to drop 6 points every 4 days and doesn't reach FG for another 5 to 6 weeks. Is that a bad thing?

Cheers!

Depends how soon you want to drink it

Most of the time that we see an infection pellicle, it's a brew that has sat a long time in primary, but i think this has more to do with sanitation than time in most cases - it just takes that long for the pellicle to form. This type of infection also depends on oxygen to live, so it implies that the headspace is not as well airlocked as it should have been.

There is some fear of yeast autolyzing but i don't think it actually happens all that often. Many homebrewers leave all of their brews in primary, on the yeast cake, for 4 weeks. Then skip secondary and go straight to the keg or bottling bucket.

I'm not even clear on what lysed yeast should taste like. If we're talking about the soy-sauce-alike meaty flavor (and cheap soy sauce gets it's flavor from hydrolyzed vegetable proteins), I've tasted that in a brown ale that was 2 weeks in primary.

Edit: Oh, but unfinished fermentation is one risk cited for underpitching. So, it might get stuck and not finish, or it might just take a long time to finish. my underpitched brown ale didn't finish for a rather long time - like 10 weeks - but turned out ok.

Are you using a hydrometer? What was the recipe?

pabloj13 said:

Are you using a hydrometer? What was the recipe?

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July 8 - 1.090 OG
July 11 - 1.064
July 14 - 1.058
July 18 - 1.052

He's either Carnac the Magnificent or he's using a hydrometer.

well, he could be using a refractometer with both brix and gravity scales, and unaware that refractometers can't be trusted post-fermentation. without some math anyway.

I am using a hydrometer. Here is the recipe.


Recipe: Belgian Strong Ale
Brewer: Jeff Tarko
Asst Brewer:
Style: Belgian Dark Strong Ale
TYPE: All Grain
Taste: (0.0)

Recipe Specifications
--------------------------
Boil Size: 8.41 gal
Post Boil Volume: 5.72 gal
Batch Size (fermenter): 5.50 gal
Bottling Volume: 5.00 gal
Estimated OG: 1.095 SG
Estimated Color: 16.3 SRM
Estimated IBU: 33.0 IBUs
Brewhouse Efficiency: 70.00 %
Est Mash Efficiency: 70.0 %
Boil Time: 90 Minutes

Ingredients:
------------
Amt Name Type # %/IBU
14 lbs 9.1 oz Pilsner (2 Row) Bel (1.4 SRM) Grain 1 71.6 %
2 lbs 14.8 oz Briess Munich Malt - 10L (12.8 SRM) Grain 2 14.4 %
7.8 oz Rahr White Wheat Malt (3.3 SRM) Grain 3 2.4 %
6.8 oz Belgian Aromatic Malt (25.0 SRM) Grain 4 2.1 %
6.1 oz Caramunich III (Weyermann) (76.0 SRM) Grain 5 1.9 %
6.0 oz Belgian Special B Malt (198.4 SRM) Grain 6 1.9 %
3.0 oz Melanoidin (Weyermann) (30.0 SRM) Grain 7 0.9 %
1 lbs Candi Sugar, Clear (0.5 SRM) Sugar 8 4.9 %
2.68 oz Hallertauer Mittelfrueh [4.00 %] - Boil Hop 9 33.0 IBUs
1.0 pkg Trappist High Gravity (Wyeast Labs #3787 Yeast 10 -


Mash Schedule: Single Infusion, Medium Body, No Mash Out
Total Grain Weight: 20 lbs 5.6 oz
----------------------------
Name Description Step Temperat Step Time
Mash In Add 24.18 qt of water at 168.9 F 153.0 F 60 min

Sparge: Fly sparge with 4.69 gal water at 168.0 F

TimpanogosSlim said:

well, he could be using a refractometer with both brix and gravity scales, and unaware that refractometers can't be trusted post-fermentation. without some math anyway.

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Exactly. Thank you.

I would warm it up to about 72. This far into fermentation you won't get the off flavors that go with a high temprature.

I thought I would give an update to where I'm at with this beer. It's been a long, slow fermentation as expected with such a high gravity beer. It's been about 5 weeks and every reading had shown a drop so I just left it ferment at 72F. My last reading only dropped 1 point so I decided to rouse the yeast by slowly swirling the carboy hoping I can squeeze the last 4 points out and get this beast bottled. I have to say, the beer tastes awesome and I can't wait to taste the end result. Thanks for all the help. Mucho appreciated!

July 9 - 1.090 (OG)
July 11 - 1.064
July 14 - 1.058
July 18 - 1.052
July 23 - 1.035
July 29 - 1.026
Aug 7 - 1.023
Aug 15 - 1.022

Looking for a FG 1.018