Can a vigorous fermentation be a sign that something went wrong?

This was my first AG and it is a relatively low gravity brew. The OG came in at 1.055.

I mashed 10lbs of Vienna in at 158 with 14 quarts for 1 hour. Then I sparged with 14 quarts at 170.

I boiled 1 oz of Fuggel for 60 minutes, got a nice cold break (kind of cool seeing everything form like that) cooling to 80 in less than five minutes.

I strained everything into the primary and then pitched that starter.

However, I did something, I thought would be OK. At the beginning of the boil when the hot break let up, I stole about a cup of wort from the pot and cooled it to 80 degrees. Then I pitched my yeast into that and ended up with this about 15 minutes later.



Now, after 18 hours I am about to have a mess on my hands.



I left plenty of head space?

I was wondering if something could have happened during the mash to result in such high fermentability. I targeted 158 to add more body to the beer. When I started the sparge the temp had only dropped 2 degrees to 156. The only thing I could think of is that the thermometer was off and I was below 153.

What is your fermentation temp?

flyangler18 said:

What is your fermentation temp?

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66 degrees and the yeast was Nottingham.

You pitched a bit warm at 80 degrees however; remember, fermentation is an exothermic reaction.

Vigorous fermentation is quite normal with many strains (including Nottingham), but it's just something to be mindful of.

flyangler18 said:

You pitched a bit warm at 80 degrees however; remember, fermentation is an exothermic reaction.

Vigorous fermentation is quite normal with many strains (including Nottingham), but it's just something to be mindful of.

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Do you think my thermometer was off during the mash and I will end up with a watery beer?

How do I check to make sure my thermometer is right?

impatient said:

Do you think my thermometer was off during the mash and I will end up with a watery beer?

How do I check to make sure my thermometer is right?

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Why do you think your thermometer is off? According to Beer Alchemy, 10 lbs of Victory should lend a post-boil gravity of 1.048 (assuming 8 gallons pre-boil down to 6 gallons at flame-out).

flyangler18 said:

Why do you think your thermometer is off? According to Beer Alchemy, 10 lbs of Victory should lend a post-boil gravity of 1.048 (assuming 8 gallons pre-boil down to 6 gallons at flame-out).

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I picked 158 as my mash target to increase unfermentables. I am hoping that the vigorous fermentation is not a sign that everything got converted, meaning my mash temp was off, resulting in a watery beer.

I just have to wait and see what happens.

I heard people talk of calibrating there thermometers, I was just wondering if I needed to check mine.

flyangler18 said:

You pitched a bit warm at 80 degrees however; remember, fermentation is an exothermic reaction.

Vigorous fermentation is quite normal with many strains (including Nottingham), but it's just something to be mindful of.

Click to expand...

Are you saying I should have brought the wort down to 66 before pitching. I guess this would make sense. I bet the wort is still higher than the basement tempurature since fermentation produces some heat. I doubt it could maintain 80 degrees thought, or, I certainly hope not. I don't like bananaas.

Diacetyl is a bigger issue from a high fermentation temp. It's pretty nasty, although I found I liked it until I was able to recognize it as an off flavor...now it turns my stomach. Weird.

I heard people talk of calibrating there thermometers, I was just wondering if I needed to check mine.

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Calibrating a thermometer is easy. You just need to check the reading against known values-- 212° for boiling and 32° in ice water; adjust accordingly. The dial style thermometers usually have an adjustment nut where you can fine tune.

Notty is a vigorous fermenter, even ambient 68*F I had to use a water bath and ice to keep the fermenter below 70*F last time I fermented with it.

I recommend using foam control drops if you are worried about blowoff. I had a beer start to blow off this morning, pulled the airlock out and put in some foam control drops. The krausen dropped within a few seconds.

80*F is warm to pitch but I generally pitch the English strains warm on purpose (70-75*F) and cool down to mid 60's since they have a tendency to flocc out if you pitch them too cold.

Dude...seriously...RDWHAHB.

A vigorous fermentation is rarely ever a problem, but I would check the thermometer's calibration. Worst case for this batch, you can add some maltodextrin to improve the body if needed.

The best way to calibrate a thermometer is an alcohol bath. An alcohol/water mix (AKA cheap vodka) will boil at 172F. I just put an empty aluminum can in a pan of water, add the vodka and heat. (People who flunked high school chemistry need not post that this technique is dangerous. It isn't.)