[war2112]

So I have one of these auto siphons to transfer the cooled wort from the kettle into the primary fermenter. Thing is, the instructions act as if you just give it a few pumps and then it will flow due to gravity as long as you keep the draw end below the liquid line in the kettle.

I could not get it to do that. I had to manually siphon it using strokes. I tried to be careful not to aerate (though is that really a problem at this point; after all you are supposed to aerate before pitching yeast) but I know I got some bubbles. everything was sanitized. What am I doing wrong?

[flars]

You'll get the best siphon action when the distance between the "from" container to the "to" container is as great as possible.  There may have been an air leak where the tubing connects to the racking cane if there was a difference in height between the two containers.

I just pour from the boil kettle into the fermentor to splash as much as possible.  This helps aerate the wort so the yeast has as much oxygen as possible for the growth phase of the fermentation.  After the pour I shake and swirl to add more oxygen until there is a large head of foam.

Edit:  It is also possible the siphon was getting plugged by hop debris.

[ynotbrusum]

My guess is the seal at the racking cane part and the tubing was letting in a lot of air, like a Venturi suction and that overwhelmed the siphon of the fluid, but it could also be the seal at the cane and the outer tube.  Be sure to take apart and store separated the cane and outer tube, otherwise the inner seal tends to bind and cause leaks.  The last point of likely failure is a crack in the cane or outer tube.

If none of those conditions are the problem, then it must be height differential - be sure that the entire receiving vessel is below the bottom of the vessel that you are racking from and you should have a good siphon condition relative to the two vessels (of course, technically, it is the relative level of the liquids that is the only concern, but keeping the two situated one fully above the other will help ensure that it flows.)

[pete b]

Yea, height differential or leak. My auto siphon works every time with just a couple pumps.
When you push it down and then draw it up does the liquid come up the larger tube with the inner racking cane? If not there's a leak.

[santoch]

+! to what they said.  It has to either be leaks or VERTICAL distance.
The higher the VERTICAL difference, the more effective the siphon will be.

[Slowbrew]

I have no additional answers to the siphoning issue. 

I siphoned from my kettle to the fermentor for years but eventually added a valve to the kettle.  It's one of the best upgrades I ever made.  For all the troubles I've heard about people having with auto-siphons over the years I'd recommend your best fix is to port your kettle and forget about siphoning.

Until then, check for leaks and make sure the vertical drop is sufficient to maintain the siphon.

Paul

[war2112]

All, thanks very much for your advice. Sounds like everybody is in agreement about the leak or vertical distance.The vertical distance is fine, the fermenting bucket was on the floor and the kettle on the Counter top so a height differential of about three feet.

I think it is definitely a leak because the hose doesn't fit snug over the Auto siphon cane. I think they gave me the wrong size hose with the kit. Should be 5/16" I believe and they gave me 7/16". I was thinking, this can't be right. It's a loose fit.

Thanks again, all! I am going to go back to the store and show them and hopefully get the right size hose for free.

[pete b]

All, thanks very much for your advice. Sounds like everybody is in agreement about the leak or vertical distance.The vertical distance is fine, the fermenting bucket was on the floor and the kettle on the Counter top so a height differential of about three feet.

I think it is definitely a leak because the hose doesn't fit snug over the Auto siphon cane. I think they gave me the wrong size hose with the kit. Should be 5/16" I believe and they gave me 7/16". I was thinking, this can't be right. It's a loose fit.

Thanks again, all! I am going to go back to the store and show them and hopefully get the right size hose for free.

Yes, it should be a very tight fit. Your not getting suction.

[Stevie]

Throw a worm clamp on there. Don't over tighten.

[pete b]

Throw a worm clamp on there. Don't over tighten.

Yes that type of plastic is kind of brittle. I've broken the neck on those racking canes before. I wish I could say it only happened once but I'm pretty sure it was twice!

[war2112]

Man, you guys rock with the advice!

Damned, worm gear would work. I see what you guys mean about not over-tightening though. Yeah, that cane would break for sure.

Yeah, it's definitely suction. I was trying to pinch the hose to the cane cause I knew it was too loose. I think I'll just get the right size hose.

Thanks again, everybody.

[war2112]

Man, you guys rock with the advice!

Damned, worm gear would work. I see what you guys mean about not over-tightening though. Yeah, that cane would break for sure.

Yeah, it's definitely suction. I was trying to pinch the hose to the cane cause I knew it was too loose. I think I'll just get the right size hose.

Thanks again, everybody.

[amichuda]

I use the 5/16 " tubing. Run some warm water over it to loosen it up, then squeeze onto the racking cane.

[war2112]

Amichuda,

Thanks! Yeah, I went back to the supply store with auto siphon and tubing in hand to show them that the tubing they gave me was too wide. They gave me 3/8 but replaced with 5/16 free of charge.

They agreed it was too loose and even a clamp that I tried did not work. Perfect - I will e bottling in 2 days so now I have the right hose for that!