Use a different, low-foaming, detergent when handwashing dishes.
When the soap foams up, the bubbles have to go somewhere and would not tend to go down the drain unless accompanied by a higher flow rate of water than you are apparently using. The dishwasher contains the bubbles until the rinse cycle.

Thank you for your response; obviously I did not express myself very clearly.
We are washing dishes in the larger part of the sink, the soap foam goes down the drain just fine. However then it starts rising from the small compartment, as if pushed up by air pressure from inside the pipes.

The air pushing the bubbles up is caused by the venturi effect of water going down the other drain.
Have you tried using less soap?

Here is a link that might be useful: Wikipedia

You make it sound like a generic problem; we know a number of people with double sinks, and none of them have this issue.

Maybe the other people are washing dishes differently. Take your detergent to their house and wash dishes the way you do, or ask them to wash dishes at your house with their detergent. I, too, think you are using too much soap. It is possible that you have a vent problem, but I do not think so.

I can tell by your writing that you are not hand washing dishes efficiently, using way too much detergent and water. There should be little detergent running down the drain until you are finished washing dishes. The most efficient way to hand wash dishes is to stopper the sink, and put in a little water with the minimum amount of detergent to make a small amount of suds. Start out with small stuff rinsing into the same sink. Move on to larger things as the sink fills adding more detergent if necessary. When the sink is full enough with water, switch to rinsing into the other sink.

You know, I've been building software systems for over 20 years, and in my experience telling the client to modify their behaviour to fix an issue is not only a non-starter, but a sure way to alienate the client. Now of course I am not a client here but simply someone asking for help, but could we just for a minute try to deal with the issue as stated? Just assume I have REALLY dirty dishes and have to use more detergent than normal.
What vent problem do you think could be responsible for this?

Thank you.

It doesn't sound like a vent problem. Perhaps your drain set-up under the sink is configured a bit differently than that of your neighbors. Could be that the two drains meet "equally" instead of one feeding into the other obliquely (with a wye) as it heads toward the trap, if that makes any sense.

If your two drains merge as in this link, you're more likely to see bubbles in the opposite sink.

Here is a link that might be useful: bubbles

It is not a vent problem since the drains for the sinks are connected together before the trap.

You can prevent the problem by using separate traps and trap arms, but it can be a real PITA to install and not violate the plumbing code.

Bad analogy even excluding the fact that you are not a customer. The dishes are standard and so it is soil. The water, plumbing and detergent are as well and all should be considered hardware. The procedure is more like the software and must be adapted to work with the existing hardware.

What would you expect if you complained about your car's clutch wearing out every 10,000 miles? Should I tell you to stop slipping it, or get a different kind of clutch?

Efficiency of hand dishwashing has been studied as far back as the 1950s. Now it might be called systems engineering. Then it was home economics. I should have included that if a lot of dishes are being washed, you should fill the second sink with hot water for rinsing rather than running fresh water over each item,

@homebound
Here is the picture of my connection under the sinks:

and it does appear to be set up in a way that is similar to the one in the link that you provided. Unfortunately, as I am not really familiar with plumbing and its terminology, the comments in that thread are incomprehensible. But could you (or others) perhaps recommend a change that might take care of the problem?

Thanks!

Hmmm, it looks like the work was done during happy hour. Get a real plumber and they will cut it out and replace with a better configuration. You have a "center waste" set-up (where they meet in the middle, then drop into the P-trap).

Either replace it with an "end waste" set-up (with the trap under the main sink) OR install a separate trap for each sink.

One last thing: use a plumber, not the guy who did that unattractive mess!

I'm late on this but completely agree with latest posters' suggestions.

Also agree that whoever did that for you shouldn't be hired again for anything having to do with drainage.

Here is an illustration I just made to help you select the proper tee.
. The one you need is the center outlet Tee
. .

What lazypup said. I don't see DW stub in that nightmare, but if you have the chance, add one. A DW actually uses about 1/4 of the water and energy that it takes to handwash dishes. Your method of handwashing uses even more than average water and energy. You're wasting money. If you can't use a DW, change the way you hand wash.

The more I look at that photo the madder I get. Not only is the "installer guy" who first assembled that nightmare not a plumber, I have serious doubts if he/she even personally knows a real plumber. In fact, judging by the results it would appear that the individual who did that was trained in the 3-stooges school of plumbing.

First off, any trained plumber would know full and well that primer is to be used sparingly,which is certainly not the case here.

Note that the trap adapter on the right hand side is about 5" higher than the one on the left. WHY?

Perhaps its because they installed the long sink tailpiece on the deep sink and the short one on the shallow sink. If they had reversed the tailpieces, putting the long one on the shallow sink and the short one on the deep sink then both tailpiece outlets would be at the same level.

Next, note the 1/8 bend offset on the line from the right hand side of the tee. That no doubt is because the cut the fixture arm too short, then glued the trap in place and it was short of being directly under the cross piece where it should be.

Now it is legal to use PVC and glue it all in place, but code requires a cleanout on the upstream end of all drain lines. If you have a removable trap that suffices as a cleanout, but since in this case the trap is glued in place, code would require a separate cleanout. Does anybody see a cleanout? I certainly don't.

Out of curiosity I went online and priced the correct fittings for this job.

A plastic slip joint type "Continuos Waste Center Outlet kit" costs a mere $11.99 and a slip joint type 1-1/2" P-trap is a paultry $5.49, add to that about $3 for a trap adapter and the job could have been done correctly for about $20 in parts and 30min labor, and thats allowing the plumber enough time to drink a coffee.

In a worst case scenario, it appear that the fixture arm coming out of the wall is offcenter and you may need to cut the fixture arm close to the wall, install and 1/8bend and bring the arm out to the trap adapter at a slight angle to properly align with the P-trap which should be centered. But then, that would only add another $2 or so.

Having spent four years in an apprenticeship I get livid when I see hackers calling themselves plumbers and making a mess like that, which ultimately makes real plumbers look bad.

Thank you for your comments. I shared them with the company that had provided the installer; they will be redoing the job; we'll see how well it turns out.

And that company's name is?....

If you use enough soap you can still have bubbles back up even with a baffled tee.

@jakethewonderdog
Disclosing the company name is tantamount to declaring war; I am not quite there yet.

Mike.

Allow me to give you a little tidbit of knowledge that will strengthen your position when dealing with the contractor.

Maintenance is the act of replacing or repairing an existing system providing you maintain the exact same configuration, and anyone can perform maintenance.

"PLUMBING" is the act of designing and installing new piping systems or reconfiguring existing systems, and by law it must be performed by certified plumbers.

If one charges a fee including barter, either directly or indirectly through the GC on the job for performing an act of Plumbing they are required to have a license or have the job overseen by a licensed plumber.

As the homeowner you have the right to insist on seeing the plumbers credentials before any work is commenced.

If they try to slip in another wannabe plumber they are guilty of "contracting without a license".

Assuming your GC has seen that installation or your photograph of it I would anticipate no difficulty with your re-do. I would anticipate difficulty of further employment for whoever did it. Can't believe other than that GC will be as appalled as all here were.

"Maintenance is the act of replacing or repairing an existing system providing you maintain the exact same configuration, and anyone can perform maintenance. "

Subject to any local rules that are in effect.

At least one jurisdiction I am familiar with requires a permit for ANYTHING expect replacing a faucet washer.

@lazypup
Thanks - does changing from a single sink to a double sink qualify as "reconfiguring an existing system"? And the law that you are referring to, is that State or Federal? I am in NJ, by the way.

1.yes.
2. I'll let them explain.

Ask you AHJ if a permit is required, especially in NJ.

NJ has a nasty habit of revoking COs at sale, and then re-inspecting to issue a new one (at least in some parts of the state).

@brickeyee
What are AHJ and COs ?

Authority Having Jurisdiction. Your local codes and permits office. The ones you file the permits with to change out your plumbing.

Certificate of Occupancy. The certification that the dwelling complies with the codes and is fit for habitation. You cannot legally live in a home without a CO.

Do you rinse after you drain the sink, try hot water 30 sec or so. In both sides 40 side last. This should flush it past the u shape trap.

Hopefully it hasn't been bubbling for the last 9 years... ;-)