Hydro-boy

[pizzaman]

Just had a strange thought whilst sitting on the porcelain lazboy. "Oh how wonderful it would be if I could check the SG of my brews without having to sanitize things, open the lid, risk oxidation, etc." (my thoughts often have an etc. in them)

Then it hit me, why not build a carboy with a built in hydrometer attached to the outside. You could get real-time SG readings by simply looking at the hydro-gauge, which I imagine would be very useful for all levels of homebrewers. Since this thought is still fresh in my mind, I only have a few basic ideas about how one would go about doing this. A quick search of the "world wide web" didn't come up with any similar ideas but, has anyone ever heard/thought of anything like this?

 

[hammer one]

I read of someone somewhere doing something like that.... BIG $... You may have to sit back down for a while.

 

[Revvy]

Kinda like a sightglass only with a hydrometer built in??? Kinda cool actually!

When I was working in radio I used to get my best ideas for commercial copy while worshipping on the same throne...

 

[llazy_llama]

If you make this work, please do let us know how it turns out.

 

[pizzaman]

I just drew up a quick prototype for one of my ideas, to help generate some suggestions.

As all I have at the moment is ale pales, this is what I will be working with. This concept uses PVC pipe attached to the side of the bucket about six inches down from the top, with a clear tube inserted into a 90 degree angle to house the hydrometer. This was nowhere near my original idea, but is something I could easily build with items I have on hand.

My main concern at the moment is sealing the pvc as most pvc cements use pretty harsh chemicals; I assume this is because pvc is typically used for plumbing where harsh chemicals aren't really an issue(toilets, bathtubs). If I were to use metal pipe I would probably end up ok.

Another idea just popped into my head to add a valve to this setup, which would allow me to take on or off the hydrometer portion, allowing for a sort of "hot-swap" setup where I can use the same hydrometer attachment for multiple buckets with the socket/valve assembly.

 

[pizzaman]

An idea of what the valve system might look like:

 

[GreenwoodRover]

That idea could also work on a better bottle if you were willing to port it.

You would also need to have the attachement extend up about 9-12" above the fill level to allow the hydro to float. You also need to put the port enough didtance below the normal fill line to all or the hydro to float.

I like the valve idea for hot swapping, you would just need to sanatize the attachement a lot.

Unless you put a co2 fitting/qd with check vavle on the top of the hydro attachment to pressure the sample back into the beer when you switched the you would either need to keep this on the bucket all the time or have one for each bucket.

Additionally I would be concerned about circulation in terms of making sure the sample in the tube attachemnt was an accurate representation of the actual mix/makeup of the fermenting wort in the main vessel.

Just spitballing here, but this looks like it could be pretty cool...

 

[pizzaman]

This is more along the lines of what I originally had in mind. Something that is completely built-in, not requiring any effort to find SG. Although this is not easily buildable at the moment, definitely something to look into in the future.

A small plastic/glass box would sit on the outside of the bucket, housing a hollow tube, which holds a small ball of mercury encased in glass. The encased mercury freely floats up and down the tube, resting at a point which would be readable on the box as the SG.

 

[pizzaman]

More research has made me realize a few flaws in both of my designs so far. For the built-in, floating ball method, the liquid would have to be filled to the exact same fill line each time, and krausen may effect the readout. The external PVC idea still seems sound, but would honestly be no different then fermenting in a bottling bucket, or any bucket with a spout, and filling the hydrometer via said spout. While both have definite strong points, I've reached the extent of my expertise in making them reliable.

A built-in digital hydrometer system may work, if they weren't so damned expensive. Maybe when I finish my electrical engineering degree I'll revisit this idea...

 

[Greenglass]

Hmmm... interesting idea. After thinking about this for a while, I can't think of a simple means of doing it that would work, though.

Just to give you an idea of the quality of my thinking p), this is the best I came up with:

Leave a hydrometer in the bucket
Glue a webcam to the inside of the lid

 

[amishland]

This idea has merit prob safest/cheapest to experiment with designs on buckets, I will ponder over it and some bells hopslam and post back here this weekend.

Few quick questions / comments:
will this sight glass chamber have to be corked? hold more pressure than the airlock or blow off tube at least

 

[Hokie]

Another question to ask (in addition to the krausen throwing off/concealing the reading) would be whether the co2 generated by the yeast would artificially lift the hydrometer higher than it should be. I think this is one of the main reason you should spin the hydrometer in the tube before taking a reading.

 

[pizzaman]

Here's a mock up of the third concept.

This one employs a ball of mercury enclosed in glass, which is suspended from the lid of the bucket by a thin metal wire. The wire extrudes above the top of the lid into a clear plastic tube where the SG can be read. The clear plastic tube would have a reading scale(not shown here) which could be :

A) slid up and down the tube to locate the waterline, and locked into place or
B) attached to a floating device via a separate metal wire to float on the water line.

Determining the water line would allow for the SG to be accurately read based on the depth of the mercury.

 

[Laughing_Gnome_Invisible]

Here's a mock up of the third concept.

This one employs a ball of mercury enclosed in glass, which is suspended from the lid of the bucket by a thin metal wire. The wire extrudes above the top of the lid into a clear plastic tube where the SG can be read. The clear plastic tube would have a reading scale(not shown here) which could be :

A) slid up and down the tube to locate the waterline, and locked into place or
B) attached to a floating device via a separate metal wire to float on the water line.

Determining the water line would allow for the SG to be accurately read based on the depth of the mercury.

Honestly, I thought the first couple of plans sucked for various reasons. But with this one I think you are getting there!!

 

[pizzaman]

Honestly, I thought the first couple of plans sucked for various reasons. But with this one I think you are getting there!!

I agree completely.

Everyone please feel free to share what you think sucks about any of my concepts so far, as this helps the design process.

 

[Laughing_Gnome_Invisible]

OK then. I think the tube at the top would need to be in two parts so that you can remove the top half in order to access the hydro easily to give it a twirl.

 

[0202]

I like the idea.

Something in me says the chamber where the hydro is floating needs
to be visibly isolated. From Krausen, C02 bubbles, etc.

How about making a bulb that can simply extract some of the wort
into a chamber with the hydro, and then you could let that sit and
sediment for 20 min, take your reading, and pump it back into the
main body of wort.

 

[pizzaman]

Something in me says the chamber where the hydro is floating needs to be visibly isolated. From Krausen, C02 bubbles, etc.

This seems to be a common concern, and one I have thought about, but has anyone ever tried measuring SG of an actively fermenting liquid? I understand that CO2 is released during the fermentation, but I'm not sure this would have an effect on an object that is floating a few inches below the water line. I wish there were some way I could test this theory with two hydrometers, 1 in a clear carboy that is actively fermenting, and 1 in an external tube with a sample of the same liquid as the first, to see if there is any detectable difference. Unfortunately I don't own any clear fermentation vessels other than my plastic 1 gallon jugs which don't have enough headspace to do this...and I only have 1 non-broken hydrometer....and even if I was able to test it this way it still would be different than the end product I've come up with which is simply an enclosed ball of mercury suspended in the liquid, rather than a hollow glass tube that extends above the water line...

hmmmm.........

 

[pizzaman]

OOps......

I just re-read the post I just replied to and realized that he wasn't talking about the CO2 effecting the physical location of the hydrometer, but rather being able to "visually" see the hydrometer, which leads me to believe he doesn't understand that the only part you need to see is outside of the bucket, away from krausen etc.

 

[pizzaman]

OK then. I think the tube at the top would need to be in two parts so that you can remove the top half in order to access the hydro easily to give it a twirl.

Ideally the top tube would be there only to hold the hydrometer scale and keep the metal wire straight up and down, and would be easily removable. I'm not sure how one would go about doing this at this point, as it would require the metal wire to go through some sort of rubber seal that is tight enough to prevent any gas leakage, but loose enough to allow the wire to float up and down freely.

If all that needs to be done is twirl the hydrometer as you say, would it work if the tube had a little spindle at the top which allowed you to spin the wire? If this is the case the glass tube at the top could be open to the bucket, which would no longer require any complicated seal for the metal wire to pass through. The tube would still be removable, but only for cleaning.

 

[Laughing_Gnome_Invisible]

Ah, sorry, I thought the tube was already open to the bucket. I had seen the tube as a vertical extension of the bucket. Nothing more than a viewing window for an elongated hydro. I need to go back and re-read the design with my clever hat on.

 

[pizzaman]

Fifth idea...I skipped the fourth cause it was dumb.

This one is a design idea for a built in digital readout. The unit is attached to the lid, with two thin metal wires hanging from it. Each wire is attached to a spool which is able to determine the exact depth it is at. The red ball is a floater, the determine the water line. The small black ball is the mercury element. The digital circuit figures out the depth of the floater and the depth of the mercury, then calculates the distance between the two in order to print out the specific gravity. It would be fairly easy to incorporate a temperature gauge into this setup.

 

[pizzaman]

Thinking more about concept 5, the wires would probably become a problem over time due to their constant submersion in the liquid, so I'm thinking of a way to eliminate the need for them.

My initial idea is to plant unique RFID tags inside each ball, which would allow you to easily determine their distance from one another while floating in the bucket. The main problem with this is that their distances would be affected if they weren't floating directly above one another. They would need to be connected by either a thin tube which they could easily float up and down, or be enclosed in a tube of some sort.

With this setup, the user would have a set of RFID balls for each fermentor(bucket or carboy in this case) which they would simply sanitize and drop into the mix. The user would also have a single RFID reader, probably the size of a small cell phone, which could be used for multiple fermentation vessels. When you want to get an SG reading, you would simply place the reader on top of the vessel and press a button to calculate the distances and determine the SG. This would prevent the need to have any kind of opening in the fermentor.

A small probe could also be attached to the floater ball to determine current temperature, which could be transmitted to the reader. If this were the case the balls would need to have a battery source which is otherwise not required for simple rfid distance calculations(maybe these could be 2 different models? One with temperature, one without..)

 

[missing link]

Someone on this forum tried to leave a hydrometer in a carboy during fermentation but the krausen stuck to it and caused the hydrometer to sink. I can't imagine how you could isolate the hydrometer from Krausen and still have the fluid it is in reflect the gravity of the wort. Even a small sample of wort that is fermenting will have krausen.

The electronic concept would be awesome.

Linc

 

[pizzaman]

Here's a visual of what the Hydroballs setup might look like:

The redball is the floater, attached to the plastic rod. The silver ring is the mercury encased in glass, which freely floats up and down the rod. Each of these has their own unique RFID tag implanted in them.

 

[nathan]

if you are modifying buckets, can you add a spigot and just pour off a tube full and test it, then drink/toss the sample? Or is this one of those invention-is-the-mother-of-necessity things like Yuri and his inventions?

a tiny drop is all you need to use the refractometer if you use the excel file to account for alcohol.

 

[pizzaman]

Thanks for the comment. If you read the bottom of the first page I did deduce that the original design would have been no better than simply filling a hydrometer tube with the spigot from a bottling bucket. Did you read any of this thread or simply look at the first picture and then reply to that?

On another note, after doing a bit of preliminary research, it looks like I'll be able to build the RFID reader for about $50 in parts from RadioSmack, plus about $10 for the LCD display and control circuit. The RFID tags can either be built or purchased, but only cost about $1 each.

 

[nathan]

I read so much of it that I started to get confused as to which type you were going to go with.

Mainly I was just curious if for you the challenge was inventing a cool new invention for the task, or jsut getting the reading. I have a tendency to find myself with a need for something, and design and build expensive crazy things to do it, when really I could have just done a cheap simple solution more quickly, BUT, sometimes I just like tinkering and making stuff to see how it'll work (my gallery is full of copper toys).

 

[pizzaman]

I have always preferred the fun way to the easy way. Anytime I can think of a reason to build something, I do.

As far as the hydro-boy is concerned, I've ditched all bucket mods and am pursuing the hydro-balls.

 

[nathan]

how much do you think it would cost? If you got it to work, it might be perfect for the big conicals folks have. I got some of the plastic 12 gallon variety and could see using it there so you can track your fermentation well.

 

[pizzaman]

It looks like I'll be able to build the RFID reader for about $50 in parts from RadioSmack, plus about $10 for the LCD display and control circuit. The RFID tags can either be built or purchased, but only cost about $1 each.

The only additional cost would be for the non-electrical hardware such as the balls and electronics housing.

Keep in mind, you would only ever need one RFID Reader, as you could use it for any number of ball assemblies. I imagine the ball assembly would cost around $10-20.

 

[GreenMan]

Here's a visual of what the Hydroballs setup might look like:


The redball is the floater, attached to the plastic rod. The silver ring is the mercury encased in glass, which freely floats up and down the rod. Each of these has their own unique RFID tag implanted in them.

Another way you could do this is two rings on a fixed rod. The rod would be fixed to the bottom of a bucket or the lid of a conical. This way the floater wouldn't have to be as big since it wouldn't have to hold up the rod as well as its own weight. This would also force the rod to be vertical. Don't know why the rod wouldn't be vertical unless you used a light weight rod material though.

Like the way you are thinking. Starting to look really good.

 

[pizzaman]

That is a good idea greenman, thanks for the input. What I'm hoping for is something that can easily be used in any fermentation vessel such as a carboy, bucket, kitty litter bin, etc. That way the final product can be built and used by any old joe...or built by me and bought for a reasonable price by any old joe.

I was planning on using a lightweight plastic for the rod material, but with a heavier disc at the bottom to keep it straight and level.

 

[hughmac]

Really a cool idea pizzaman. Get that remote temperature sensor in there, and you can automatically adjust the reading for temp. No more math!

I do think your biggest challenge will be krausen or other junk. If you built in a small sonic vibrator (like in my toothbrush), you could probably shake off all the junk before taking a reading.

This thing's getting expensive!

Hmmm ... and now that I think about it, I think it needs to be upside down from how you have it, unless I'm missing something. You should have the donut as the floater (green belown), and the rod with mercury ball on the bottom is down in the wort, and the rod & ball moves up and down while the donut remains stationary on the surface. I think? A cap (like you have on the bottom) on the top to make it all one device? Pardon my Paint work, but like this:

Another problem might be the whole thing getting pushed to the side by bubbles and it 'sticking' to the side. There's a stopper in one of my glass carboys that always seems to be sticking to the side.

I want some!

 

[pizzaman]

now that I think about it, I think it needs to be upside down from how you have it, unless I'm missing something

The only purpose of the rod is to keep the two balls aligned vertically to one another. The SG calculation is done by the space between the two balls, which is calculated by the RFID reader. In your drawing the rod would need to have lots of room to move up or down depending on the SG of the liquid, which it would run out of room as the SG becomes lower, which would cause the mercury to rise, rising the rod in the process. This would force the rod into the top of the fermentor, and could possibly inhibit proper readings. With the rod pointing down and attached to the floater, there is no need for the rod to move, only the mercury ring.

The sticking to the side is a very good observation. I suppose the floater ball would need to have some thin rods extruding from it horizontally to prevent it from getting too close to the edge. As far as krausen is concerned, if after initial testing I can determine that it would be an issue I could easily stick a small dc motor into the setup and add a button to the RFID reader to pulse the motor on and off, which would vibrate the ball assembly free of any external gunk. The DC motor would be very inexpensive, but it would require the use of batteries which I hope to avoid. On that note, I think I've found a way to incorporate a temperature gauge into the setup without the use of batteries....

Here is the current visual depiction, with added features:

 

[0202]

So the whole array is at the bottom of the bucket, and the
distance between the RFID devices gets translated into a
Specific Gravity?

I like that.

My original concern for the hydro being isolated was to prevent
the floating element from picking up interference via floating
Krausen, yeast floaties, hops, etc etc etc. I was thinking very
modular for cleaning, etc and removing the hydro array from the
body of wort was my primary concern.

The RFID idea is interesting.

 

[hughmac]

The only purpose of the rod is to keep the two balls aligned vertically to one another. The SG calculation is done by the space between the two balls, which is calculated by the RFID reader. In your drawing the rod would need to have lots of room to move up or down depending on the SG of the liquid, which it would run out of room as the SG becomes lower, which would cause the mercury to rise, rising the rod in the process. This would force the rod into the top of the fermentor, and could possibly inhibit proper readings. With the rod pointing down and attached to the floater, there is no need for the rod to move, only the mercury ring.

How high my rod goes up (omfg haha) is totally dependent on how much weight is in the red ball. It would depend on how accurate the RFID readers were ... if they are extremely accurate, you might only need the rod to move up and down an inch. But definitely the primary issue with this type of design.

However, maybe I'm missing something, but I don't think your donut will work. The density of the wort is relatively constant at all depths. Your donut will do one of three things: float to the top, sink to the bottom, or (very unlikely) be neutrally buoyant -- in which case it will stay wherever you put it. If it's neutrally buoyant, as the gravity goes down it will sink to the bottom.

The sticking to the side is a very good observation. I suppose the floater ball would need to have some thin rods extruding from it horizontally to prevent it from getting too close to the edge. As far as krausen is concerned, if after initial testing I can determine that it would be an issue I could easily stick a small dc motor into the setup and add a button to the RFID reader to pulse the motor on and off, which would vibrate the ball assembly free of any external gunk. The DC motor would be very inexpensive, but it would require the use of batteries which I hope to avoid. On that note, I think I've found a way to incorporate a temperature gauge into the setup without the use of batteries....

Yeah, I think the thin rods would work fine. Good solution. Good idea to just 'see if it works' before trying to incorporate the DC motor into it.

 

[GreenwoodRover]

Here is the current visual depiction, with added features:

I like that idea with one mod/hybrid for buckets.
I would go with the 2 doughnuts and the disk at the bottom.
Thread the rod at the top and make it as deep as the bucket.
You could drill a hole at the top of the fermentor and use plastic nuts and rubber washers to make a seal. One nut and washer on each side of the lid. the rod would stick up/out about 1" or so. That way you can put it into any lid you want and take it apart/off for a full clean and sanatizing...
I'd sketch it but my skilz are teh suk...

 

[pizzaman]

maybe I'm missing something, but I don't think your donut will work.

The donut is a glass ring filled with a set amount of mercury and air. This should make it work just like a typical hydrometer, which is filled with mercury and air. I would of course have to do a bit of testing to get the correct amounts of each in order to have it float at a level that is determined by the SG.

 

[hughmac]

The donut is a glass ring filled with a set amount of mercury and air. This should make it work just like a typical hydrometer, which is filled with mercury and air. I would of course have to do a bit of testing to get the correct amounts of each in order to have it float at a level that is determined by the SG.

Typical hydrometers float on the surface, and the level they float at is determined by differences in the density of air, and the density of the wort. It looks like your donut isn't floating, it's submerged. There is no wort density difference above and below it, it's the same above and below (for all practical purposes), so the ring will sink to the bottom, or float to the top. You COULD develop a ring that would be neutrally buoyant, but it would only be neutrally buoyant at one SG. Then it would sink all the way to the bottom as soon as the SG dropped at all.