Cheap and easy aeration gadget

[jds]

We all (well, most of us, anyhow) know the importance of aerating wort prior to pitching yeast. As a KISS brewer, I don't oxygenate. My usual aeration method has been either carboy shaking or a wire whip before transferring to the fermenter. Until yesterday.

The LHBS proprietor suggested the following trick, and it works great:

1. Take a six-inch length of racking cane
2. Heat a straightened paperclip in a flame
3. Use the hot paperclip to melt a series of small holes through the wall of the racking cane.
4. Insert racking cane into transfer tubing when transferring cooled wort to fermenter.

My racking cane ended up looking something like the below:

Except that I twisted the cane a little bit so all the holes weren't along the same axis.

I used it yesterday when transferring a 1.055 OG cream ale to the fermenter. The little holes serve to suck in air, which makes tiny bubbles in the stream of wort. Tiny bubbles = more surface area = more oxygen transfer (and memories of Don Ho, too)

By putting this widget right at the top of my 6.5G carboy, I generated a layer of froth about 3" thick after racking. The package of dry notty I pitched with had started to make foam within six hours of pitching at 3 PM yesterday, and is pushing gas out the 1-1/4 inch blowoff tube this morning. I'm sold. This widget is part of my routine now.

 

[MrShake]

I likey! Now I need to find a 1/2inch racking cane to fit the output hose of my keggle.. hehehe

 

[conpewter]

Good thought, I've read about similar ideas before. I'd be tempted to somehow filter the air that gets in though.

 

[Coastarine]

Bloody brilliant. I'm comfortable with not filtering since it'd be no worse than the wire wisk method.

 

[BeerCanuck]

Excellent tip JDS
might even dedicate a racking cane into an aeration wand using this principal.

Cheers
BeerCanuck

 

[Yooper]

Someone (is it Orfy?) has a similar aeration "wand", but made out of metal. He had pictures of it a year or two ago, and it seemed to work great. I think if you're using a keggle, with a CFC especially, that would be awesome. I've seen some sprayers for sale in the HBS cataloques- same principle, but with a spray nozzle on the plastic racking cane.

Great ingenuity to make it with what you have!

 

[FlyGuy]

This is a very clever little device. But recognize that it may have limitations for oxygenating your wort. According to Wyeast, these types of 'siphon sprayers' don't actually get much O2 into your wort (only about half the amount of what you would get by shaking/spalshing wort in your carboy for 40 seconds.

http://www.wyeastlab.com/hb_oxygenation.cfm

 

[jds]

It's a good point, FlyGuy. I've tried sprayers on the end of the racking cane before, and was unimpressed. I think the difference here is that the air is entrained into the stream rather than the stream being sprayed into the air. Based solely on my subjective estimate of how much foam I have in the carboy, I think this does better than a sprayer.

Anybody have a DO meter handy? I'm sure I can come up with an excuse to get one at work...

 

[Yooper]

Anybody have a DO meter handy? I'm sure I can come up with an excuse to get one at work...

Oh, that's a great idea! You could compare the results, and post it for us! I love that.

 

[FlyGuy]

It's a good point, FlyGuy. I've tried sprayers on the end of the racking cane before, and was unimpressed. I think the difference here is that the air is entrained into the stream rather than the stream being sprayed into the air. Based solely on my subjective estimate of how much foam I have in the carboy, I think this does better than a sprayer.

Well that sounds promising then! I may have to try it. Very clever indeed!

 

[Alamo_Beer]

What if you used both? This and the sprayer......


Personally I use a paint stirrer on a drill but I run it backwards so the wort splashes up. I run if for maybe 3-5 min. I've only started to do this on the last couple of batches but fermentation has taken off 'better' it seems and I've been hitting my FG numbers.....

 

[Coastarine]

I'm just guessing here, but I think putting the restriction of a spraying nozzle on the wand would slow the flowrate and defeat the effect of pulling the bubbles in through the holes. You'd end up squirting wort out of the holes, which would still aerate it, but not exactly the effect you're talking about.

 

[Joe Camel]

I'm just guessing here, but I think putting the restriction of a spraying nozzle on the wand would slow the flowrate and defeat the effect of pulling the bubbles in through the holes. You'd end up squirting wort out of the holes, which would still aerate it, but not exactly the effect you're talking about.

You're right, this is called a Venturi tube. The principle is that the piece of tube with the holes in it has to be a smaller diameter than the rest of the tubing. This makes the wort speed up through the restriction and cause a pressure drop, sucking air in through the holes. If you you restrict it again at the end with a spraying nozzle, you'll lose the benefit.

One thing you can try is to cut your siphon hose about halfway up and insert the venturi tube there so that there is a foot or two of hose below it. This will allow the air bubbles more time and distance to swirl in the moving wort. This will expose the wort to more surface area of air and should improve oxygenation

 

[Orfy]

I've been using this successfully for years but from copper.

 

[Philip1993]

I was thinking that you should put it just above the wort surface inside the fermenter. This way the air/wort mixture gets the maximum contact time. It would make starting the siphon a bit tougher, but...

 

[stever]

I've been using this successfully for years but from copper.

Lets hope you don't run your hand across those holes, they look a wee bit sharp.

Neat idea though, I think I will need to give this a try.

 

[jds]

One thing you can try is to cut your siphon hose about halfway up and insert the venturi tube there so that there is a foot or two of hose below it. This will allow the air bubbles more time and distance to swirl in the moving wort. This will expose the wort to more surface area of air and should improve oxygenation

Yup, I'll be doing this on the next brew -- I'll insert it about halfway down transfer tube.

I was thinking that you should put it just above the wort surface inside the fermenter. This way the air/wort mixture gets the maximum contact time. It would make starting the siphon a bit tougher, but...

My keg boiler sits on a stand about 25 inches off the ground, so no siphoning necessary.

Like the copper, Orfy. What's the hole diameter?

 

[Schlenkerla]

You're right, this is called a Venturi tube. The principle is that the piece of tube with the holes in it has to be a smaller diameter than the rest of the tubing. This makes the wort speed up through the restriction and cause a pressure drop, sucking air in through the holes. If you you restrict it again at the end with a spraying nozzle, you'll lose the benefit.

One thing you can try is to cut your siphon hose about halfway up and insert the venturi tube there so that there is a foot or two of hose below it. This will allow the air bubbles more time and distance to swirl in the moving wort. This will expose the wort to more surface area of air and should improve oxygenation

Are we talking the sum of area of all the small holes vs the discharge area?

Do I understand this right?

If thats the case you can add lots of holes.

If the hole size is 1/32" Then

at 1/8" hose : 15 holes​

at 1/4" hose : 60 holes​

at 3/8" hose : 135 holes​

at 1/2" hose : 240 holes​

 

[Joe Camel]

Are we talking the sum of area of all the small holes vs the discharge area?

Do I understand this right?

If thats the case you can add lots of holes.

If the hole size is 1/32" Then

at 1/8" hose : 15 holes​

at 1/4" hose : 60 holes​

at 3/8" hose : 135 holes​

at 1/2" hose : 240 holes​

No, I'm a bit confused about the question, but you really dont need that many holes.

If you insert a small piece of 3/8" outer diameter racking cane into a 3/8id tubing, you'll restrict the cross-sectional area by about half (diameter squared = 4/64 vs 9/64) If you put too many holes in and they add up to the difference or greater, the benefit is lost, you 'll just squirt out the holes rather than suck in air.
That being said, you'll probably do better with 1 or 2 big holes than multiple small ones, 1 1/16" hole has the same cross-sectional area as 4 1/32" ones but the surface tension across the hole will be much less so it'll be easier to suck air in with a smaller pressure drop.

I'd say start with one 1/16" hole and see how it goes with a water siphon, if it looks good, drill another until you don't see gain or it craps out. Then get another piece of cane and drill one or two fewer than the crap out number.

 

[jds]

I've probably got 20 paperclip-sized holes in my cane. I'm guessing the holes are (reaches for caliper...) about .050" diameter, based on the paperclip on my desk being .040 dia.

When I look carefully at the cane while it's operating, I see that most of the air comes in the first few holes. This makes sense to me.

I think you'd have to make a LOT of holes to get the wort to come out without restricting the flow somewhere downstream. Given that this gadget is for the KISS-centric brew rig, I'm not planning on optimizing it beyond maybe putting it elsewhere in my outflow hose.

 

[Schlenkerla]

This is a pretty cool idea. I'm gonna try this. I did some reading.....

I wonder this will work even better after attaching another hose to this section of tube.

http://en.wikipedia.org/wiki/Venturi_effect

 

[BierMuncher]

Thanks for the idea. I did this yesterday. I used a piece of flexible tubing instead of a piece of racking cane. Worked great.

 

[WortMonger]

Wow, a big thanks for the idea from me as well. I got the bug and made one myself from an older unused kettle pick-up tube (hence the threaded end on the contraption).

Here is a wide shot for you.

and... a close-up showing the holes better.

For all those wondering, I ran this directly after my Blichmann Thrumometer (which takes my 1/2" tubing down to a 3/8" tubing size restricting the flow). I used spare unused parts from my brewery so I went with a brass 3/8" nipple soldered to a copper 45* street elbow that is of course soldered to the rest of the old copper kettle pick-up. I like it because drilling into the hex meant the perfect placement for the holes to be right as the device expands back into 1/2" causing the Venturi effect. I tried it with water and had noticeable aeration. I only did two holes and think that is plenty. I plugged one hole while testing and noticed no difference until both were plugged. Someone could comment if I need more or not and am just not noticing it, but I can always add more if I need to.

 

[undallas]

this look like a good idea to me...
Is there any concern with contamination/infection?
I guess if we rinse/soak the sprayer/dispenser after each use, we should have less risk here... Am I right?

thanks

 

[BeerCanuck]

You're right, this is called a Venturi tube. The principle is that the piece of tube with the holes in it has to be a smaller diameter than the rest of the tubing. This makes the wort speed up through the restriction and cause a pressure drop, sucking air in through the holes. If you you restrict it again at the end with a spraying nozzle, you'll lose the benefit.

One thing you can try is to cut your siphon hose about halfway up and insert the venturi tube there so that there is a foot or two of hose below it. This will allow the air bubbles more time and distance to swirl in the moving wort. This will expose the wort to more surface area of air and should improve oxygenation

I tried the aeration gadget based on the above concept on my last brew session. I only had 1 or 2 pin holes in the venturi tube.
Best aeration yet

Cheers
BeerCanuck

 

[noremorse1]

Awesome gadget... but I was reading Danstar's page last night and they said aerating with dry yeast is unnecessary. I will assume you built a starter with it... cause then its necessary according to them.

 

[jds]

Interesting point, nomorese1. Here's some stuff I cut-and-pasted from Danstar's website.

Yeast need a trace amount of oxygen in an anaerobic fermentation such as brewing to produce lipids in the cell wall. With out O2 the cell cannot metabolize the squalene to the next step which is a lipid. The lipids make the cell wall elastic and fluid. This allows the mother cell to produce babies, buds, in the early part of the fermentation and keeps the cell wall fluid as the alcohol level increases. With out lipids the cell wall becomes leathery and prevents bud from being formed at the beginning of the fermentation and slows down the sugar from transporting into the cell and prevents the alcohol from transporting out of the cell near the end of the fermentation. The alcohol level builds up inside the cell and becomes toxic then deadly.

Lallemand packs the maximum amount of lipids into the cell wall that is possible during the aerobic production of the yeast at the factory. When you inoculate this yeast into a starter or into the mash, the yeast can double about three time before it runs out of lipids and the growth will stop. There is about 5% lipids in the dry yeast.

In a very general view:

At each doubling it will split the lipids with out making more lipids (no O2). The first split leaves 2.5% for each daughter cell. The second split leaves 1.25% for each daughter cell. The next split leaves 0.63%. This is the low level that stops yeast multiplication. Unless you add O2 the reproduction will stop.

When you produce 3-5% alcohol beer this is no problem. It is when you produce higher alcohol beer or inoculate at a lower rate, that you need to add O2 to produce more yeast and for alcohol tolerance near the end of fermentation. You definitely need added O2 when you reuse the yeast for the next inoculum.

If you prepare a starter culture you will need added O2. in the starter and perhaps in the main mash as a precaution. You will need to follow the precautions as mentioned above. If the mash is designed to produce 3-5% alcohol you may not need added O2. Brewing above that needs added O2.

So, the way I read this is that Danstar says "There are enough lipids in our dry yeast that aeration isn't as important, for 'standard' beer." Interesting. This may also play into the many anecdotal accounts we see here on fast and powerful fermentation starts with Nottingham.

Nevertheless, I aerate the wort no matter what I'm pitching into it. It's an ingrained part of my process -- and, IMO, still necessary to make the best beer one can.

 

[BooneDocks]

The beer running through the cane pulls air in through the holes? Scratching my head as I can't quite see how much aeration would occur from this.

 

[EvilTOJ]

It's not much aeration compared to 5 gallons, but think about it like this; it's aerating in small amounts, but there's also a small amount of wort in the racking cane at any one time. It's also moving at a constant flow.

 

[Boerderij_Kabouter]

The venturi is an awesome idea for brewing and will produce significantly better aeration than shaking and likely better than using an aeration system (air pump etc.).

Joe Camels comments should be taken to heart. Fewer, larger holes will be significantly better.

Also, the higher velocity the flow (the larger the pressure drop) the more air per volume of wort will be drawn into the stream. So a 3/8 cane with two large (relative) holes would be better than a 1/2 cane with a bunch of holes.

Also, the idea of moving the venturi up the line will make a big difference as the contact time between the air and the wort will be increased.