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Old 11-04-2009, 05:05 PM   #1
May 2009
Posts: 25

Don't know if anyone else is doing this or not but I got the idea to put my hydrometer in a tube of wort and leave it in a corner of the kitchen with a piece of foil on top. It's activity mirrors what is happening in the primary and I can tell when fermentation is complete by monitoring the S.G. as it goes along. As far as I'm concerned it beats multiple samples and if it gets contaminated some way, no big deal.

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Old 11-04-2009, 05:09 PM   #2
Parker36's Avatar
Sep 2007
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It is not entirely accurate, however. The temperature can fluctuate more with a smaller volume amongst other things that could affect fermentation rate. If you worry about losing beer to sample,s look into refractometers. Or you can just get a couple of batches going at once, set them and forget them for a couple of weeks and they will be good to go.

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Old 11-04-2009, 05:10 PM   #3
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or just let it sit and be patient, After ~ a week or so, take a reading. Even if it finishes fermenting in 3 days you still don't want to rack away from Primary. The yeast still have a lot of work to do in cleaning up after themselves.
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Old 11-04-2009, 05:13 PM   #4
Mar 2009
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only problem is the fact that the tube is now a completely separate mini carboy. there is no grantee that the two will ferment at the same rate. smaller volumes of liquid change temp way easier than larger amount. temperature affects the speed and quality of fermentation. if you want an up to the moment gravity reading put the hydrometer in the carboy itself. the only problem with this approach is you wont be able to read the value because of the karasean. but really you can see when the hydrometer stops getting lower in the carboy then measure the result later.

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Old 11-04-2009, 05:19 PM   #5
Jan 2009
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I do it that way all the time and I don't cover it with anything. There's a fair chance that the sample may get contaminated with bacteria or mold and go south. I typically don't draw the sample until the fermentation is mostly complete figuring some alcohol in the sample will help protect it. If it does get contaminated, it may finish out lower than the beer in the fermenter. I'd toss it if that happened and draw a fresh sample. You can also get a good idea of the beer color. Keep in mind that the results are only an approximation due to the limited amount of yeast in the sample. You can also speed up the fermentation rate of the sample by keeping it in a warmer area than the fermenter. The sample might not taste great, but it will get you results faster if that is what you want.

I use this method to get an approximation of the final gravity and not so much to know when the main fermentation is complete. I give my typical ales ten days in the primary no matter what. Then I rack to a secondary with some finings to allow the beer to clarify before racking to a keg.

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Old 11-04-2009, 05:23 PM   #6
May 2009
Los Angeles
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The shape of the fermenter and the pressure in the fermenter also play a role in how the beer ferments. While I like the concept, it just doesn't work well in practice.

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Old 11-04-2009, 05:29 PM   #7
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Dec 2007
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Don't know if anyone else is doing this or not but I got the idea to put my hydrometer in a tube of wort and leave it in a corner of the kitchen with a piece of foil on top. It's activity mirrors what is happening in the primary and I can tell when fermentation is complete by monitoring the S.G. as it goes along. As far as I'm concerned it beats multiple samples and if it gets contaminated some way, no big deal
Actually that "satellite fermenter" idea is nothing new, AND it will only tell you WHAT YOUR BEER WILL FINISH AT, NOT when your 5 gallon batch of beer will be done.

It's used to measure attenuation of the yeast, not rate of fermentation.

It will take yeast a lot less time to chew through 12 ounces of wort than it will 5 don't trust that silly thing that someone came up with because they are too afraid to take samples from their beer as being accurate.

If you do take that as "gospel" you more than likely are rushing your beer off the yeast way to soon. You know "bottle Bombs" or suddenly posting an "is my beer in secondary ruined?" thread because now that you moved it to secondary because the "satellite" said it was done, you now have this scary looking growth that you have never seen in your bucket (because the lid is one) that suddenly grew on top of your wort and is ugly as sin....which we of course will tell you to rdwhahb because that is just krausen and it formed because you racked too soon and the yeast is still trying to work to make beer for you.

The idea came from commercial breweries, but you have to realize when they are using in it a 3 or 7 or 10bbl fermentaion setup, that their sattelite looks like this.

And they are drawing off hydro sample out of that bucket just like we do.

And they are STILL going to be taking readings and tasting the REAL beer in the ACTUAL FERMENTER, before making any determination.

It's been adopted by some home brewers, and unfortunately gets perpetuated by people (mostly noobs scared of taking real hydro readings) but it's about as accurate as airlock bubbling, (and you know where I count that in terms of fermentation gauges- slightly below the astrological calender )

With proper sanitzation you can open up the bucket and take hydro reading with no fear....

Here's what I do....

1) With a spray bottle filled with starsan I spray the lid of my bucket, or the mouth of the carboy, including the bung. Then I spray my turkey baster inside and out with sanitizer.

2) remove lid

3) Draw Sample

4) fill sample jar (usualy 2-3 turky baster draws

5)Spray bung or lid with sanitizer again

6) Close lid or bung

6) take reading

It is less than 30 seconds from the time the lid is removed until it is closed again.

Probably less if you have help.
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Old 11-04-2009, 05:36 PM   #8
Dec 2007
Buffalo, NY
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Probably the best way to monitor fermentation would be:

1.) Make sure yeast start fermenting

2.) Walk away for three weeks.

Imagine. This place would be a ghost town if everyone did that. I'll admit I'm just as guilty as anyone when it comes to obsessive fermentation monitoring
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Old 11-04-2009, 06:26 PM   #9
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Jan 2009
Central Florida
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Sounds like a sort of Fast Ferment Test. There's an article (authored by HBT's own Kaiser) in this months Zymurgy mag. Here's the original online version of the article. But it's results are not used quite like you're intending (as mentioned above).
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