Consistently stuck fermentations?

Hey guys, I'm on extract/specialty grain batch #3, all three batches have been stuck. My first batch was a Vanilla Bourbon porter on oak chips that was stuck, but I managed to successfully "un-stick" it by rousing the yeast, and moving it to a warmer temperature.

The second batch is a sweet stout that was stuck, I roused the yeast, nothing, I re-pitched some Nottingham to get it going again, that also did nothing. So I was forced to bottle it rather than throw it out, I bottled it at 1.030, but it was supposed to settle at 1.016-1.020. I made a thread on this beer here: https://www.homebrewtalk.com/f163/still-stuck-after-re-pitch-223007/

Now my third batch which is an English ordinary bitter, is stuck at 1.018, where it should be about 1.012 or lower. I racked it to secondary last week, hoping to wake the yeast up, and still stuck.

The ferm temps have been well within the correct range on all of these beers 69-71 degrees, and each one had the readings taken after about a month in primary (with exception to three weeks for the bitter), so I know I gave the beer plenty of time to ferment. The beers taste great, no infections, sanitation has been thorough, everything done right, I cant figure this out, I'm doing everything to the tee and it is frustrating the hell out of me to the point where I am cursing out loud every time I check the gravity on my beer! What could cause all three of my brews to become stuck!?!

One thing I am curious about is that I have used drinking water (the single gallon bottles you can purchase at the grocery store) for all of these batches, no tap water was used. Could this be my problem? Not enough minerals for the yeast? Thanks!

Did you use a good yeast nutrient and aerate sufficiently (or use something like olive oil)? I'd also check on the minerals in the water you use, calcium in particular is very important to yeast health, and you don't want to have less than 50 ppm in your brewing water.

One of my HBT blog entries has lots of suggestions for getting a stuck ferment going again, but it's best to prevent them altogether.

ArcaneXor said:

Did you use a good yeast nutrient and aerate sufficiently (or use something like olive oil)? I'd also check on the minerals in the water you use, calcium in particular is very important to yeast health, and you don't want to have less than 50 ppm in your brewing water.

One of my HBT blog entries has lots of suggestions for getting a stuck ferment going again, but it's best to prevent them altogether.

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No yeast nutrient. Is it absolutely necessary in every batch? I am also not familiar with the use of olive oil, does it substitute aeration? The only aeration was from the vigorous pouring of the wort in the primary...

Blone said:

No yeast nutrient. Is it absolutely necessary in every batch? I am also not familiar with the use of olive oil, does it substitute aeration? The only aeration was from the vigorous pouring of the wort in the primary...

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Wort does supply most nutrients the yeast need, although zinc can be limiting in some cases. Yeast nutrient provides them in a more labile form, and I have seen nothing but positive results from using nutrients in starters as well as full batches. I prefer Wyeast nutrient.

A single drop of olive oil can supplement or (according to some) replace the need for aeration. More than a drop is overkill and can, again according to some, affect head retention and flavor. It apparently provides some key ingredients to the yeast that they otherwise synthesize using dissolved oxygen in the wort. I have used it successfully to supplement aeration for some time now. Simply pouring usually won't be enough to give you the 8 ppm oxygen the yeast needs to truly be happy and reproduce. Since I am lazy and have lost Better Bottles due to overzealous shaking, I use the olive oil, but shaking is the more common and traditional method, and one that works very well. Alternatives are air and oxygen pumps, but they are not necessarily superior to the shaking method.

How are you deciding where they should finish? By the recipe? Are the recipes for extract/partial mash, or using a different brand of extract?
Perhaps you are using extract that doesn't ferment out well, too large an amount of specialty grains, or some other source of too many unfermentables?
If temp changes, adding yeast, and giving sufficient time hasn't changed things a likely culprit is the extract or grains, or for an all grain brewer too high a mash temperature.

My guess is that it has to do with low pitching rates. Did you use liquid or dry yeast?

ArcaneXor said:

Wort does supply most nutrients the yeast need, although zinc can be limiting in some cases. Yeast nutrient provides them in a more labile form, and I have seen nothing but positive results from using nutrients in starters as well as full batches. I prefer Wyeast nutrient.

A single drop of olive oil can supplement or (according to some) replace the need for aeration. More than a drop is overkill and can, again according to some, affect head retention and flavor. It apparently provides some key ingredients to the yeast that they otherwise synthesize using dissolved oxygen in the wort. I have used it successfully to supplement aeration for some time now. Simply pouring usually won't be enough to give you the 8 ppm oxygen the yeast needs to truly be happy and reproduce. Since I am lazy and have lost Better Bottles due to overzealous shaking, I use the olive oil, but shaking is the more common and traditional method, and one that works very well. Alternatives are air and oxygen pumps, but they are not necessarily superior to the shaking method.

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Good info, thanks!

pdxal said:

How are you deciding where they should finish? By the recipe? Are the recipes for extract/partial mash, or using a different brand of extract?
Perhaps you are using extract that doesn't ferment out well, too large an amount of specialty grains, or some other source of too many unfermentables?
If temp changes, adding yeast, and giving sufficient time hasn't changed things a likely culprit is the extract or grains, or for an all grain brewer too high a mash temperature.

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Ya, usually by the recipe is how I am expecting it to finish. The first extract batch was a different brand of LME than the last two, and that is the one that got stuck, but I was able to get it going again.

These are extract batches with specialty grains (I am unsure if this would be called partial mash). But they are recipes from local home brew shops that have been made by them successfully using the same brand of ingredients and quantities of ingredients.

I'll have to try a kit with a different brand of extract from a different source like Northern, or Austin and see if that helps..

sjbeerman said:

My guess is that it has to do with low pitching rates. Did you use liquid or dry yeast?

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Dry yeast. All the quantities pitched were per the LBS's recommendation, and were brews they have made themselves sucessfully. The stout was even pitched with safale, and nottingham as per the LBS's recommendation, then I re-pitched nottingham again, with no luck.

+1 to the low pitching rates. 1 dry packet of yeast typically isn't enough to get a healthy fermentation going on a beer over 1.050. Next time get two packets or some high quality liquid yeast and make a starter.

Tossing a packet of nottingham in typically won't do you any good. Your beer lacks the oxygen and nutrients that yeast need to actually ferment.

Blone said:

Dry yeast. All the quantities pitched were per the LBS's recommendation, and were brews they have made themselves sucessfully. The stout was even pitched with safale, and nottingham as per the LBS's recommendation, then I re-pitched nottingham again, with no luck.

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What were the OGs of these brews? How many grams of yeast? Did you rehydrate the yeast? Typically, pitching dry yeast on a stuck fermentation won't work unless there are a lot of simple sugars present.

sjbeerman said:

What were the OGs of these brews? How many grams of yeast? Did you rehydrate the yeast? Typically, pitching dry yeast on a stuck fermentation won't work unless there are a lot of simple sugars present.

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Porter og 1.045
Stout og 1.065
Bitter og 1.040

I used the entire amount that comes in a packet of yeast, except on the stout, where I used two packets, per the recipe. I don't remember how many grams they were exactly. The only reason I pitched the dry yeast on the stuck ferm, is because the local brew shop recommended it

One thing I would recommend is to properly rehydrate the yeast before pitching. Although I know that many people pitch directly without rehydration, you can loose quite a bit of your cell count by not rehydrating and therefore underattenuate your beer. During the rehydration process, I would also recommend using yeast nutrient. I believe there is a specific nutrient that is used with dry yeast. I would also recommend making sure that the wort is well aerated before pitching. It appears that you pitched the proper amount of yeast, but I wonder how viable that yeast was. Typically, dry yeast can last a long time, if properly stored.

1) Aerate really well. Place the lid on, and shake the **** out of it. When you think you have done as much as possible, repeat the process. You can get enough aeration from shaking, but you really have to shake it. I have never used a stone, and always finish well.

Yeast will not reproduce without O2. If the yeast do not reproduce, you will have a small colony, that will get stressed out. Even if they do finish the beer, underpitching can result in fusel alcohols and lots of unwanted esters.

2) Rehydrate dry yeast or make a starter if using liquid yeast. Straight pitching of dry yeast can kill half the cells; If you have lots of O2, it should not matter, but every little bit helps.

3) If you need to re-pitch, you are better off making a starter or small beer and pitching that. You need to get lots of yeast cells, and a partially fermented wort does not provide the nutrients or O2 for the yeast to reproduce, and the alcohol environment is not good to new yeast either.