lol - composty krout!
... no idea... what else has been creeping into your krout recipe? perhaps a day-dream of smelly socks? or rotting tomatoes? ... i suggest examining outside the box of the recipe and observing what else is going on...

That is sad! Maybe try checking on it frequently to see when the bad taste develops... and start with just cabbage and try to isolate from that?

What recipe are you using??

I don't make brine at all-
try just chopping the veggies - and crushing with your hands- while you mix the salt in. release the juices of the veggies themselves, and keep packing down into your container. (what container are you using)
a gal. bucket works, a crock pot works (with a round opening where a plate fits into it) -

and pack and punch and squeeze the veggies a BUNCH. you will get some liquid. I sometimes will have to add just about 1/4-1/2 cup of water - then i put a plate on it (i use my crockpot right now) and a jar of water for weight on it, a towel over it to prevent flies from landing. I push the jar down every day a bit more, more liquid comes out.

Around the edge is sometimes a little slimy - so just scrape that off the top.

All this i learned from Sandor Katz. Works every time for me.

my current kraut:
cabbage, raddish, dikon, turnips, hot peppers, bell peppers, carrots, ginger, garlic, pepper, mustard seed, corriander, sweet potato gratted.
(i like it hot) (everything was grown by me or by friends in my area so its whats in season now)

i think if your getting a slimy- smelly thing going on- it might be because you added so much water?

are the veggies staying crisp at all?

good luck.

Remember it is the salt that creates the proper environment for the "good" bacteria to turn the cabbage sugars into lactic acid and yummy flavor compounds. The salt also kills "bad" organisms that could populate your batch and create toxins. Never stray far from the required salt from your recipe. Both the good and bad bacteria live naturally on the cabbage, but you certainly don't want any other bacteria from dirty hands or utensils. Keep it clean. Steer clear of wooden cutting boards because they cannot be properly cleaned and sanitized.
Tip one: cabbage must be grated fine enough to get juice enough to cover the cabbage in your crock. Chopped dry cabbage sticking up out of the juice will NOT work.
Tip two: you MUST have an air-lock! The process is supposed to keep air out, but let the gasses from fermentation escape. Put a high-quality clean plastic bag ( that will not leak) in the top several inches of the crock and fill the plastic bag with clean water to within a quarter inch of the top of the crock. This bag of water weighs down the cabbage to keep it submerged under its own juice, plus it forms a good seal that form-fits to the inside of the crock to let gasses escape, but keep fresh air out. Check the integrity and water level of your air-lock daily. Put some salt in the plastic bag water to discourage anything from growing in it and loosely tie the bag closed or use a rubber band to seal the top of it so water will not spill out or evaporate for the duration of the process.
Tip 3: Temperature is important! Too warm and you will create a lot of lactic acid and gasses real fast, but the product will lack fine flavor. Too cold and the process will go very slow or never start. Just right and you will get the required lactic acid in mellow time and you will also get the delicious flavor compounds that distinguish just OK product from great product.

Tip 4: The first phase of bacteria that begin to transform the salted cabbage into kraut eventually diminish and die off while at the same time a new wave of different bacteria begin to take over to finish off the process. If you arrest the process early before the whole team has finished doing their thing, you will get some nasty kraut.

Tip 5: Fluffy and flaky salt, for example kosher salt might not provide a true measurement of salt. Another way to think of it is that a tablespoon of some light fluffy salt does not equal a tablespoon of dense granular salt crystals. Find recipes that call for ingredients by weight instead of volume. As an example: 5 pounds of grated cabbage to X??? grams of salt.

have fun, good luck