Smelly bokashi, too much liquid, fruit flies: how to diagnose and fix your bucket

Print

A bokashi that is working well goes unnoticed: with the lid closed, it barely smells at all in the kitchen, and when you open it, it gives off a sour smell, rather like a jar of pickled gherkins. When the smell becomes genuinely unpleasant, the bucket is overflowing with liquid or fruit flies are buzzing around it, something has gone off track.

The good news is that the causes are almost always the same: air, moisture and the amount of bran. Nothing is lost as long as you act quickly. Here is how to make the right diagnosis, symptom by symptom.

Normal and abnormal smells: learning to tell the difference

The first step is knowing what is normal. A healthy bokashi smells:

• sour, of vinegar, pickled gherkins or sauerkraut;
• sometimes of cider, beer or with a slight alcoholic note;
• fairly strongly when opened, especially when you drain the liquid, which always smells stronger than the contents.

An abnormal smell, on the other hand, is unmistakable: rotten eggs, spoiled meat, rotting cabbage, sewage, or a pungent smell of ammonia. It means the waste is starting to rot instead of ferment.

Did you know?

Even a bucket that has developed an unpleasant smell can almost always be saved. As long as coloured mould has not taken over the surface, a few simple steps are enough to restart lactic fermentation.

Putrid, rotten-egg or ammonia smell: causes and remedies

The causes

• Too much air: lid not properly closed, dirty or damaged seal, tap left open, opening too often, waste not pressed down enough.
• Too little bran: a single uncovered layer is enough to let putrefaction take hold.
• Too much moisture: this is the most common cause. Soggy contents smell bad.
• Stagnant liquid: left too long at the bottom of the bucket, it eventually rots.
• Too much heat: direct sunlight, or close to an oven or radiator.
• A lot of protein at once: an ammonia smell often appears when you add a large quantity of meat, fish or cheese without increasing the amount of bran.

What to do

1. Sprinkle a good handful of bran over the whole surface.
2. Press down firmly. Never stir the contents: you would let air in and the smell would get worse.
3. Drain the liquid every day for a few days.
4. Check the lid seal and clean the rim.
5. For the next additions, cut the waste smaller and be more generous with the bran.

If green, blue or black mould comes with the smell, follow our guide Mould in bokashi instead, which explains when a bucket can be saved and when it is better to get rid of it.

Too much liquid, soggy or slimy contents

The amount of liquid depends mainly on what you put in the bucket. Fruit and vegetables release a lot; bread, rice and pasta very little. Contents sitting in liquid or turning slimy usually have one of these causes: soggy peelings, leftovers in sauce or soup, liquid not drained often enough, or a clogged grid that no longer lets anything drain through.

• Drain every day while the liquid is flowing freely, then every two or three days.
• Drain before adding: let washed peelings and wet leftovers drain for a few minutes in the sink. No liquids in the bucket: no soup, no milk, no leftover sauce.
• Add something absorbent: a little more bran, torn-up non-glossy newspaper, a cardboard egg box, brown cardboard or a piece of stale bread. Avoid glossy paper and magazines.
• Unclog the drainage if the liquid no longer runs down: slide a long blade down the side of the bucket to the grid to reopen a channel, without turning over the contents.

A telltale sign: condensation under the lid. It shows that the contents are too wet, often even before any smell appears.

Emy's tip

Put half a sheet of crumpled newspaper at the bottom of the bucket, on the grid, before the first layer. It absorbs excess liquid and stops small pieces from clogging the holes.

On the other hand, a bucket that produces hardly any liquid is perfectly normal, especially in winter or with dry waste. All the draining steps are explained in detail in the guide Looking after your bokashi.

No fermentation smell at all

Your bucket smells of nothing, neither good nor bad, and nothing seems to be happening? There are three possible causes:

• Bran that is too old or poorly stored, left in a damp place or open for too long. Good bran smells yeasty or sour; if it smells musty or no longer smells of anything, replace it. See the guide Bokashi bran.
• The cold: fermentation slows down considerably in cool conditions. Bring the bucket into a heated room, ideally between 18 and 25 °C.
• Too little bran: increase the amount with each layer.

Then give it time: it often takes one to two weeks for the sour smell to become clearly established.

Fruit flies or flies

A properly closed bucket does not let insects in. If fruit flies appear, they have found a way in or been brought in with the waste. These little vinegar flies are attracted by the smell of ripe fruit and fermentation, and they readily lay their eggs on peelings left out in the open.

• Close the lid firmly and check the seal; clean the rim, where stuck-on scraps attract insects.
• Cover each layer with bran straight away, so that no waste is left exposed.
• Empty your small kitchen bin often: it is what attracts fruit flies, far more than the bucket.
• Set a trap near the bucket: a small glass of cider vinegar with a drop of washing-up liquid.

If you find larvae (maggots), flies have laid eggs in the bucket while it was open or through a leak. A few larvae on the surface: remove them, add bran, press down and close the lid carefully. If there are a lot of them, bury all the contents deep in the garden, rinse the bucket and start again.

Swollen bucket, lid under pressure

A domed lid, or one that "puffs" when opened, is nothing to worry about. Fermentation produces a little gas, especially with sugary waste such as fruit or bread. If the smell remains sour, briefly open the lid to let the gas out, close it again straight away, and check that the tap is not blocked. A lid under pressure is only a concern if it comes with a putrid smell.

If you also have a wormery, bear in mind that its smells are not dealt with in the same way: our guide Bad smells in the wormery will help you.

Summary: troubleshooting at a glance

• Sour, vinegar or pickled gherkin smell: all is well, carry on.
• Putrid or rotten-egg smell: extra bran, pressing down, daily draining, seal checked.
• Ammonia smell: more bran on meat, fish and dairy.
• Soggy contents, condensation under the lid: draining, well-drained waste, newspaper or cardboard.
• No smell: replace the bran, move the bucket somewhere warm, increase the amount.
• Fruit flies: check the lid and rim, empty the small bin more often.
• Lots of maggots: bury the contents deep, rinse the bucket, start afresh.
• Domed lid, sour smell: fermentation gas, nothing serious.

Key points

Almost all bokashi problems come down to three things: too much air, too much water or not enough bran. Pressing down, draining and sprinkling generously solve the vast majority of cases.

To avoid trouble from the start, good bran makes all the difference: our Bokashi EM compost activator, made on the farm, keeps well in a dry place in a tightly closed container.

In short

A healthy bokashi smells sour when opened and of almost nothing with the lid closed. A putrid or ammonia smell points to air, too much moisture, stagnant liquid or a lack of bran: add bran, press down without ever stirring, drain every day and check the seal. To deal with excess liquid, drain the waste and add paper or cardboard. Fruit flies come mainly from the small kitchen bin and a poorly closed lid, and a domed lid is just fermentation gas. In almost every case, the bucket can be saved.

Related products

Urbalive Bokashi composter

Capacity 10.6 litres, available individually or in sets of 2

€80.97

Best Seller

Bokashi Confort Composter

14-litre capacity, available individually or as a set of 2

€50.22

Bokashi Composter Skaza Organko 2

Capacity 9.6 litres, sold individually or in a set of 2

€83.01

Best Seller

Bokashi EM compost activator | 1 kg bag

Individually or in sets of 2 or 3 bags

€8.15

Other topics in the guide

Vermicomposting30 sheets →Composting25 sheets →EM micro-organisms26 sheets →