Hydrometer in fermentor

How are you going to accurately read a small line on a hydrometer floating in the middle of a carboy through all the krausen (whether active or dried and crusted)? If in a bucket, why not just put in and take out? Also, dried krausen krust will change the measurement as it adds weight to the instrument beyond the standard weight to balance it.

 

Also, god forbid something would happen to the hydrometer and it cracked/broke, I can guarantee you would not want shards of glass and lead floating around in your fermenting beer.

 

That's how I do it. Open lid, insert hydrometer. I've never had an infection from doing this.

 

I don't think your friend has much practical brewing experience.

you can put it in there to make a measurement but you can't leave it in there. like @jbakajust1 mentions it will become covered in hops and yeast. you can't read it. and it is generally not a good idea to be put anything in unfermented beer long term.

get a refractometer if you don't like to waste any beer.
Cheers.

 

Yea I have thought about this idea, but ^ refractometer is the better option.

 

The CO2 present in the beer can also cause off readings. You need to de-gas it.

 

How accurate are refractometers for post fermentation? I thought I read the measurment can be way off in the presence of the alcohol.

 

Correct it with http://seanterrill.com/2012/01/06/refractometer-calculator/.
I've checked it against hydrometers and vibrating u densitometers and its perfectly accurate even with alc present.

 

The actual measurement is very off, but there are calculators to get you fairly close when this reading is combined with the original refractometer reading pre fermentation. There is one built into the BrewCipher program.

EDIT: @ssam posted the same.

 

Okay, that makes much more sense, sorry for the misread. If using a bucket, there shouldn't be an issue doing that.

 

I must have misread too as I thought he was questioning if he can leave it in there full-time.

 

I bought a speidel mostly for the spigot so samples are easy to pull. I usually put over 5 gallons of wort into the fermenter so I don't worry about losing a gravity sample. I like taking the samples for two reasons 1) gravity check 2) taste test.

If you can clearly see the markings then that works. Sometimes I find it a pain to get a good reading with the jar because the hydrometer always wants to settle With the wrong side facing me.

 

I ill generally do that - if fermenting in a bucket, I'll sanitize the hydrometer, pop the lid, and place it in, giving it a spin to make sure that there isn't any bubbles or stuff stuck to it.
If I'm in a carboy, I've put in in and left it there - after the krausen has fallen - to make sure.
I have a Brett IPA going now that I dropped the hydrometer in over the weekend to check. With a carboy, I can't get it out easily, so I leave it in there.

 

I've done that during secondary fermentation with stouts, in a different carboy than primary fermentation; just dropped in the sanitized hydrometer and left it in for weeks. No much/any krausen to worry about.

 

I definitely agree not to leave it in the primary, but I'm still content with checking in the bucket, despite the reasons above. I'm a homebrewer, not a pro Brewer, and I don't mind not having an absolute accurate reading due to not de-gassing, inability to be level with hydrometer, etc. I'm also not checking FG with krausen still on the beer. If the point is to figure out if fermentation is complete or not this method works fine.