[brewthru]

There are times when 5 gallons sits in a cold chamber (around 32F) for a while before a keg is drained and I can use. Even though I carefully transfer the primary into a clean and sanitized secondary and place the secondary in the cold chamber the beer continues to ferment in the cold environment. This leads to higher-than-expected ABV. No, there is no infection causing.

I’m thinking, in the future, of adding potassium metabisulphite when transferring from primary to secondary when needing to store in the cold chamber.  How much potassium metabisulphite per 5 gallons to arrest continued fermentation?

Thanks.

[majorvices]

It sounds like the beer isn't finished fermenting before you rack it to secondary. When beer is finished it is stabilized and shouldn't continue fermentation. The obvious exception to this would be if you had a diastaticus infection (or other type infection). I recently had a cross contamination from a saison to a 6 gallon English barley wine. BW dried out to about 1.009. It was the same fermenter that the saison had been in so obviously I needed to clean better (it doesn't take much diastaticus to cross contaminate a fermentation!).

Obviously this might not be your issue exactly but beer should be stable before racking and cold crashing and it should not continue to ferment. Otherwise no brewer would be able to package and sell their beer. And I have commercially brewed, shipped and sold for over 10 years and not once did I ever have to metabisulphite to stop a fermentation. Even in homebrewing for nearly 25 years I have very rarely had a beer continue to dry out after fermentation has been stopped unless there was a problem with fermentation in the beginning (slow, sluggish fermentation) or an infection.

But, to answer your question I believe that wine makers use about 50 ppm potassium metabisulphite to stop fermentation without adding flavor (or head aches, which I sometimes get from sulphites, including a red face).

[brewthru]

What about pasteurization? Isn't beer pasteurized to reduce spoilage/fermentation and increase shelf life by commercial brewers? If so, I don't have the means to pasteurize my brews.

What time frame (days or months) are you writing about in your post?

Beer was transferred from primary when the TG was reached. I transferred to secondary as I wasn't ready to immediately keg.

I know people, including me, have problems with sodium metabisulphite. That's why I suggested potassium metabisulphite. Perhaps, potassium sorbate is better for arresting fermentation?

Thanks.

[kramerog]

I agree with majorvices that is sounds like the beer hasn't finished fermenting. It is pretty hard to stop an active fermentation without impacting flavor.

There is no reason to think that if someone is sensitive to metabisulfite that potassium metabisulfite is the solution. Sorbate AFAIK interferes with yeast reproduction so it is unlikely to stop fermentation. Metabisulfite and sorbate are used together in meadmaking to prevent fermentation from backsweetening the mead.

[RC]

Keep in mind that you will still see bubbles coming through the airlock once in a while. Maybe this is why you think it is still fermenting? Dormant yeast consume their glycogen reserves (albeit very slowly) to stay alive until their next feast, and this produces CO2. This doesn't affect FG because the sugars are coming entirely from within the yeast cell.

But if the FG moves downward during this storage period, then yeah that beer is either not fully attenuated yet, or it is infected.

If the beers are tasting like otherwise normal beers after this storage period, it could be both--i.e. not fully attenuated and also "infected" with a lager strain.

[brewthru]

Making me wonder... problem began after I switched to using Star San for the sanitizer (after cleaning the keg). Previously, I was using iodophor, but was concerned about the staining and no rinse (since it's form of iodine).

Perhaps, I should return to using iodophor instead of Star San?

[denny]

Making me wonder... problem began after I switched to using Star San for the sanitizer (after cleaning the keg). Previously, I was using iodophor, but was concerned about the staining and no rinse (since it's form of iodine).

Perhaps, I should return to using iodophor instead of Star San?

If you do, don't rinse it.  But I'd make a definite identification of the problem before I attempted to solve it.

[brewthru]

I kegged a brew on November 21, 2021 that sit in the cold chamber for months. Gravity reading was very low.

However, upon drinking some on November 22, 2021 I am tasting some sweet flavors. If the gravity reading was accurate would not all the sweet be gone? IMO, the taste/falvor of the brew doesn't match the TG reading.

I know CO2 bubbles will raise the hydrometer and give an inaccurate reading. What can give a low hydrometer (inaccurate) reading?

[denny]

I kegged a brew on November 21, 2021 that sit in the cold chamber for months. Gravity reading was very low.

However, upon drinking some on November 22, 2021 I am tasting some sweet flavors. If the gravity reading was accurate would not all the sweet be gone? IMO, the taste/falvor of the brew doesn't match the TG reading.

I know CO2 bubbles will raise the hydrometer and give an inaccurate reading. What can give a low hydrometer (inaccurate) reading?

A low FG does not necessarily mean a sweet beer.

A cracked hydrometer, or one that has lost its calibration, can give you a low reading.

K Meta alone will not stop fermentation.

[majorvices]

What about pasteurization? Isn't beer pasteurized to reduce spoilage/fermentation and increase shelf life by commercial brewers? If so, I don't have the means to pasteurize my brews.

What time frame (days or months) are you writing about in your post?

Beer was transferred from primary when the TG was reached. I transferred to secondary as I wasn't ready to immediately keg.

I know people, including me, have problems with sodium metabisulphite. That's why I suggested potassium metabisulphite. Perhaps, potassium sorbate is better for arresting fermentation?

Thanks.

It's very uncommon for craft breweries to pasteurize their beer, FWIW.

[denny]

What about pasteurization? Isn't beer pasteurized to reduce spoilage/fermentation and increase shelf life by commercial brewers? If so, I don't have the means to pasteurize my brews.

What time frame (days or months) are you writing about in your post?

Beer was transferred from primary when the TG was reached. I transferred to secondary as I wasn't ready to immediately keg.

I know people, including me, have problems with sodium metabisulphite. That's why I suggested potassium metabisulphite. Perhaps, potassium sorbate is better for arresting fermentation?

Thanks.

It's very uncommon for craft breweries to pasteurize their beer, FWIW.

Yep.  Offhand, I don't know of one that does.

[KellerBrauer]

I am inclined to agree with the brewers who say that either the hydrometer is bad / no longer calibrated, or the beer is infected.  I can’t think of any logical reason why a home brewer would need to stop fermentation in a conventional beer.  Complete fermentation in some cases, takes a couple weeks.  So, maybe you’re not waiting long enough???  Fermentation is complete if you test the same gravity for 3-4 days.

[brewthru]

As I originally posted the beer sat in the cold chamber much, much longer than I originally planned. This normally doesn't happen.

[majorvices]

As I originally posted the beer sat in the cold chamber much, much longer than I originally planned. This normally doesn't happen.

Once a beer is finished fermenting it should be stable. I have beer that has aged for years that hasn't changed FG.

The good news is you say it "normally doesn't happen". I misunderstood your original post and thought this was a regular occurrence.