Two bokashi bins: why you need them and how to organise the rotation

Print

When people first discover bokashi, they often think one bin is enough. Then comes the day it is full: it has to stay closed for at least two weeks to ferment… and the evening's peelings have nowhere to go. That is why almost every set of instructions, ours included, recommends working with two bins.

This guide explains how to organise the rotation week after week, how much activator to plan for over the year, and what to do if your rhythm doesn't fit this pattern.

The problem: a full bin needs to rest

While you are filling the bin, fermentation is under way but not finished: the top layers have only just gone in. Once the bin is full, you close it and leave it alone for at least two weeks, at room temperature, without opening it. This resting time allows the lactic acid bacteria to acidify the whole contents and stabilise the waste. We go into these timings in our guide to fermentation time and the signs that bokashi is ready.

During those two weeks, your kitchen scraps keep coming. Without a second bin, you would have to throw them out with the rubbish, or reopen the fermenting bin, letting air in at the wrong moment.

Key points

One bin fills while the other ferments. That is the whole idea: you never stop sorting your scraps, and each bin has time to ferment properly.

The two-bin cycle, week by week

Let's take a household that fills a bin in about two weeks, the ideal rhythm. We'll call the bins A and B.

1. Weeks 1 and 2: you fill bin A, layer by layer, with activator, pressing down each time. You drain off the liquid every two or three days.
2. End of week 2: bin A is full. You add a final layer of activator, press down and close it. It goes off to rest.
3. Weeks 3 and 4: you fill bin B. Bin A ferments; you simply carry on draining its liquid, without opening the lid.
4. End of week 4: bin B is full and goes off to rest. Bin A has fermented for two weeks: you empty it (into the garden, a composter or a soil container), rinse it, and it is ready to go back into service.
5. Week 5: you start filling bin A again. And so on.

This rhythm gives roughly one bin emptied every two weeks, or a good twenty-odd fermented bins a year. To find out what to do with them, see our guide to burying bokashi in the garden, or the one on solutions without a garden. In the diagram: the bin being filled (1) and the closed bin fermenting (2), then they swap.

Emy's tip

Stick a small label on the lid of the bin going off to rest and write the closing date on it: you'll see at a glance when it will be ready.

How much activator to plan for over the year?

Consumption depends on the amount of waste, its type (meat, fish and very moist scraps need more) and the season. Here at the farm, we estimate that a two-person household uses about 2 kg of activator a year, or roughly six months for a 1 kg bag. A family of four commonly uses 2 to 6 kg a year, and a household that adds a lot of meat, fish or moist scraps will be at the top end of the range.

It's best always to have a little in reserve: a half-filled bin waiting for its activator ferments poorly. Keep your supply tightly closed, dry and away from light. Our Bokashi EM Compost Activator is made on the farm; if you'd rather make your own, the full method is in our guide to making your own bokashi activator.

What if my rhythm doesn't fit?

You produce little waste

If your bin takes more than a month to fill, it is probably too big for you. Each opening lets in a little air, and very slow filling increases the risk of mould on the top layers. Two solutions:

• Choose smaller bins, such as two 9.6-litre Skaza Organko 2 Bokashi Composters.
• Batch your additions: keep scraps in a small closed caddy and only tip them into the bokashi once a day, or every other day. The bin is opened less often, and fermentation is all the better for it.

You produce a lot of waste

If a bin fills in less than a week, the second one won't have finished resting by the time the first is full. Move up to larger bins, such as the kit of two 15.3-litre bins of the Skaza Essential Bokashi Composter, or add a third bin to the rotation. Some users who produce more than a litre of scraps a day even work with three or four bins.

You can't empty straight away

The ground is frozen, the garden is too far away, you're going away for a few days? The fermented bin can wait. Tightly closed and drained regularly, it stays stable for weeks, and even several months according to the experience of many users. It's best to use it within the following months, but there's no rush to do it that very day.

The real issue is that a bin that's waiting is a bin that's out of use. If this happens to you often, there are two options:

• A third bin, acting as a buffer in winter or during busy periods.
• A large airtight storage container, such as a plastic box with a sealed lid: you transfer the contents of the fermented bins into it, onto a layer of newspaper, pressing down well and closing it again immediately. The bins are freed up, and the stock waits for spring. Remember to drain all the liquid from the bin before transferring it: excess liquid is the main enemy of storage.

We cover how to organise things through the seasons in our guide bokashi in winter, in summer and during the holidays.

Did you know?

Once fermentation is complete, frost does bokashi no harm. In the Nordic countries, users store their fermented bins in a shed all winter and bury them when the ground thaws.

Two identical bins or different ones?

Nothing requires you to have two identical bins, but it is more practical: same capacity, same compactor, same routine, and the parts are interchangeable. That's why most of our models come in a set of two. When you get started, don't wait until the first bin is full to get the second: you'll be caught short. To get your first bin off to a good start, follow our method to start bokashi step by step.

In summary

A full bin must stay closed for at least two weeks: the second bin takes over during that time, and the rotation keeps going without interruption. Choose bins that you fill in one to two weeks, allow about 2 kg of activator a year for two people, and plan for a third bin or an airtight storage container if you can't always empty straight away. A fermented bin, tightly closed and drained, can wait without any problem.

Related products

Best Seller

Bokashi Confort Composter

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

£34.06 €40.83

Skaza Essential Bokashi Composter

Capacity 15.3 litres, set of 2 buckets

£53.53 €64.17

Urbalive Bokashi Composter

Capacity 10.6 litres, available singly or in a set of 2

£54.91 €65.83

Best Seller

Bokashi EM compost activator | 1 kg bag

Individually or in sets of 2 or 3 bags

£5.99 €7.18

Other topics in the guide

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