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Not Enough Yeast?

So I’m on my second brew, which is a winter warmer, and took the recommendation of using a yeast starter for fermentation. The OG of the wort is 1.071, but I only used a 650ml starter. In the first 24 hours the airlock was bubbling ferociously, but after 48 hours the airlock has almost completely stopped. Did I not pitch enough yeast? Should I pitch more? Will not pitching enough yeast just completely ruin the beer?

Airlock activity does not mean fermentation activity! (reverse is also true)

First of all, you did the right thing making starter. The worst that will happen if you underpitched is that the yeast could get stressed. This can cause a lot of perceivable off-flavors, like fusel/hot alcohols and/or acetaldehyde (green apple/pear).

A couple other questions:

-What temperature was your starter and your wort when you pitched
-What is the ambient temp and fermenter temp as it is fermenting?
-Had the starter completely fermented out before you pitched it? When did you start your starter?
-what yeast did you use? S-04/Nottingham?

Finally, on to what you are looking for, a recommendation: leave it for a week. On Tuesday, 10/23, pull a sample (either with a gravity thief or turkey baster, clean and sanitized) and check your gravity with your hydrometer (if you don’t have one, order it today and you will have it in time…you’re welcome, host). If it is in the 1.030-1.050 range, fermentation did stall and you will need to adapt, improvise, overcome. However, I don’t think this will happen. You will probably be in the mid/high teens.

THEN (this is the hard part), leave it in the primary for another 3-4 weeks. A beer of this gravity will benefit from a long primary fermentation, and taking it off the yeast (ie a “secondary”) will likely do more harm than good. One of the things that will happen will be that the yeast will clean up some of the off-flavors that may have been created.

Your beer is going to be fine. In fact, if you can put a few bottles away and have them next year, I bet they will be on the fringe of excellent!

Thanks for the response and recommendation. As far as temp goes for both at pitching time, both the yeast and wort were at room temperature, roughly 70-72 degrees F. It is currently in a closet that ranges from 68*-72*. The fermenter temp stays around the 70 mark. The starter had completely fermented out as it had begun to seperate, and I started it about 13 hours before pitching time. The yeast was a dry yeast, Danstar Windsor Ale Yeast.

Let me know your thoughts on whether any of this could be causing some fermenting problems.

It depends on how you define “problem”.

Will you make beer? Yes. Will you make good beer? Yes. Will you make GREAT beer? Maybe. Would it win a competition? Depends on who is judging!

I’m not sure how perceptive your palette is, or the palettes of those who will be drinking your beer. You are fermenting on the warm side, but the reality is thats what most people do. You will likely pick up SOME of the off-flavors I mentioned, but they might work with this style. I underpitched my first winter warmer, but it turned out good, and it was great after a year.

Your first investment (honestly before going all grain) should be in a chest freezer and dual stage temp controller, depending on your level of obsession with this ‘hobby’ and whether you have the space. On your next batch, split it into two batches, ferment one in your closet and the other in a swamp chiller (google it), and taste them side-by-side. My prediction is you will be amazed of the difference between fermenting @ 65 degrees and fermenting at room temp. The thing to remember is the fermenter can get 5-10 degrees warmer than the room its in as the yeast are generating heat as they metabolize sugars.

Leave this on the yeast for several weeks after airlock activity stops… AND let us know how it turns out!

With dry yeast, you did not need to make a yeast starter, but it probably did not hurt.

Fermentation temps were a little warm, you should be fine

So…I went ahead and got a gravity reading tonight. Unfortunately, it seems, that I have a halted fermentation. It came out to a reading of about 1.034. What do I do now?

I’d imagine they’re just taking a break so to speak. Give it a few more weeks. A beer like that… I’d not even think about it or touch it for 4-6 weeks.

Extract, partial mash or all grain? Recipe?

Did you decant the starter or pour the whole thing in?

I would definitely pitch some yeast. I’ve never tried that method either, but I would think that there wouldn’t be enough yeast dropping out in the secondary to get a healthy fermentation.
Can’t say that for sure, but that’s my intuition.


You need more than one gravity reading over a period of time before you can say it halted/stalled. Take another reading tomorrow, the next day, or better yet, next week and see if it dropped.

If you’re using a refractometer you must adjust the reading due to the presence of alcohol.

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