Never ending fermentation? 11 days in primary and still bubbling once every 5 sec

[sjbeerman]

Thank you MalFet.

Look at how much more information can be exchanged and shared, and how much learning can go on when we don't just slam someone for mentioning that their airlock was bubbling. There are a lot of other threads that have ended with "Well, I guess I should just let it go another couple weeks and relax" rather than sharing the details and helping a new brewer refine their process.

Sorry to those who might find my approach offending, but I am trying to get more people to understand the process and what they can do to make the best beer instead of just "RDWHAHB." I would rather "RAHAKAB" (Relax And Have A Kick Ass Beer)

 

[sjbeerman]

I cup for each starter.

In general, it is better to weigh the amount of DME added rather than using cup measurements. One cup may not actually be one cup if it is not well compacted. This can offset your starter gravity and therefore the health of the yeast.

 

[JLW]

In general, it is better to weigh the amount of DME added rather than using cup measurements. One cup may not actually be one cup if it is not well compacted. This can offset your starter gravity and therefore the health of the yeast.

I have since purchased a nice digital scale. I think I need to do more research on starters to understand more of the science behind them. The directions provided by the LHBS are nice but I have found to be a little lacking the deeper i have gotten into brewing and understanding the science.

 

[sjbeerman]

I have since purchased a nice digital scale. I think I need to do more research on starters to understand more of the science behind them. The directions provided by the LHBS are nice but I have found to be a little lacking the deeper i have gotten into brewing and understanding the science.

I would strongly recommend the book "Yeast" by Jamil Z. and Chris White for an in depth discussion of yeast and fermentation. I would also recommend Palmer's "How to Brew" if you don't already own it. These are my two most valuable Home Brew books.

 

[MachineShopBrewing]

I think I need to do more research on starters to understand more of the science behind them.

Here is a good primer
http://www.mrmalty.com/pitching.php

 

[JLW]

Fascinating article. What i take from it for my above scenario is:

1. I probably under pitched to begin with. Based on the math in this article for this beer I would have needed something like 298,065,000,000 yeast cells (assuming I did the math correctly). I probably had at best 100B yeast cells.

2. I also believe that I made my yeast starter too early. In the article it talks about for small starters you want to pitch within 6 to 8 hours. I made my starter 48 hours ahead of time

3. I also believe I used too little DME in my starter. I believe I would have needed another 1/2 cup of DME for the correct amount.

Thanks for teaching me how to fish.

If you guys are ever in Richmond let me know the beers are on me.

 

[MalFet]

Fascinating article. What i take from it for my above scenario is:

1. I probably under pitched to begin with. Based on the math in this article for this beer I would have needed something like 298,065,000,000 yeast cells (assuming I did the math correctly). I probably had at best 100B yeast cells.

2. I also believe that I made my yeast starter too early. In the article it talks about for small starters you want to pitch within 6 to 8 hours. I made my starter 48 hours ahead of time

3. I also believe I used too little DME in my starter. I believe I would have needed another 1/2 cup of DME for the correct amount.

Thanks for teaching me how to fish.

If you guys are ever in Richmond let me know the beers are on me.

Generally correct. The only thing I would comment on is pitching time. The community is more or less divided in half about pitching starters at high krausen vs. pitching starters after crash-cooling and decanting. The more research I do, the less I like the idea of pitching at high activity. Each step of my starters gets two days on the stir plate and two days in the fridge. That said, others might offer you other opinions.

1.040 is a good gravity for a starter, unless you are culturing from a very small number of cells to begin with (i.e., culturing dregs or from a frozen sample).

 

[JLW]

Update:

It's been 48 hours since the last gravity reading which was a clear 1.038. I took a new reading on batch 1 and it has come in at 1.032/1.034 so I believe it's still fermenting. I think this beer will need to continue to ferment in primary for at least another week.

I didn't take a gravity reading on batch 2 since it has already reach terminal gravity.

 

[MalFet]

Update:

It's been 48 hours since the last gravity reading which was a clear 1.038. I took a new reading on batch 1 and it has come in at 1.032/1.034 so I believe it's still fermenting. I think this beer will need to continue to ferment in primary for at least another week.

I didn't take a gravity reading on batch 2 since it has already reach terminal gravity.

Great! Do take another reading of batch 2 at some point, just to make sure nothing weird is happening. For the future, the starter stuff I mentioned should help you to get steadier fermentation.

 

[JLW]

I'm brewing a porter based on George Washington's porter recipe on Presidents day and made sure I have enough yeast.

One other thought. This morning I gave batch 1 a good swirl and double wrapped in with towels to bring the temp up. So I think that may have got it going again.

Thanks again for all the advice.

 

[el_caro]

In general, it is better to weigh the amount of DME added rather than using cup measurements. One cup may not actually be one cup if it is not well compacted. This can offset your starter gravity and therefore the health of the yeast.

I too prefer measurements like millilitres and grams but how do you convert a cup to weight for DME?
Reason I ask is I was looking at the FAQs on WhiteLabs site and they recommend 1 cup DME to 2 pints of water for starters.

 

[MachineShopBrewing]

I too prefer measurements like millilitres and grams but how do you convert a cup to weight for DME?

Don't need to. Just use a 10:1 ratio. 1000ml water:100g DME, 2000ml:200g etc...

 

[el_caro]

Thanks. Yes I had seen that ratio posted by many experts which made me wonder why WhiteLabs would talk volumes for DME rather than weight. Guess they figure some brewers may not have digital scales just volume measures.

 

[Cervezero1960]

People always preaching this thing about bubbles and fermentation are two different things and that the only accurate gauge to know whether fermentation is finished or not , is by taking a hydrometer reading. Well, that is very true, but why risk the chance of air getting in your fermenter by running multiple hydrometer tests. Bubbles, are CO2 and CO2 is a direct by-product of fermentation, so don't tell me that airlock bubbles and fermentation are two different things

 

[Likefully]

Well, that is very true, but why risk the chance of air getting in your fermenter by running multiple hydrometer tests. Bubbles, are CO2 and CO2 is a direct by-product of fermentation, so don't tell me that airlock bubbles and fermentation are two different things

I think CO2 keeps being released well after fermentation has ended. I recently split a large batch and used S04 in one and S05 in the other. S05 kept bubbling even after it reached its terminal gravity and was still bubbling (albeit slowly) when I bottled, more than 2 weeks after pitching. The beer has come out fine so I know I didn't bottle too early.

 

[kombat]

Bubbles, are CO2 and CO2 is a direct by-product of fermentation, so don't tell me that airlock bubbles and fermentation are two different things

While you're right that the bubbles are CO2, the issue is that there are multiple reasons for why that CO2 is coming out of the airlock rather that just staying in the fermenter.

During fermentation, the CO2 exits through the airlock because the pressure inside the fermenter exceeds the outside air pressure. So the CO2 gets "pushed" out the airlock.

But the mistake you're making is in assuming that fermentation is the only cause of a pressure differential. If the pressure outside the fermenter decreases (such as when a low pressure weather front passes over your area), then the pressure inside the fermenter will be relatively higher than the air outside of it. CO2 will vent out the airlock to equalize the pressures again, even though no fermentation is actually occurring.

Likewise, if the temperature of the room containing the fermenter warms up, this will produce a drop in air pressure (warm air is less dense than cold air). Again, CO2 will vent out of the airlock until the pressures inside and outside of the fermenter are equal again.

So, yes, a gravity reading is the only way to know whether or not fermentation is still occurring. A bubbling airlock does not necessarily mean the yeast are producing CO2.