We analysed the Amazon.co.uk subcategory Fermentation and kept only products with at least 200 reviews and 4.3 stars. Ranked by estimated monthly revenue, the ten below run from £8.55 of wine yeast to a £51.99 pack of argon capsules — and those capsules belong to a wine preservation system that Amazon has filed in the wrong drawer.
The top earner has nothing to do with fermenting: six argon capsules for a Coravin wine system at £51.99, or about £8.70 a capsule.
Check the price on AmazonThe top earner has nothing to do with fermenting: six argon capsules for a Coravin wine system at £51.99, or about £8.70 a capsule.
The unit leader at 664 sales: 10 g of live milk kefir grains, a culture rather than equipment, which is why it ships from the seller and not a warehouse.
A plain food bucket with a lid and metal handle at £13.24 — no airlock, no tap, but it is the vessel most 23-litre recipes quietly assume you have.
Weights are what keep vegetables under the brine, and this is the popular set: four glass discs with lift handles at £12.99, around £3.25 each.
The whole small-batch answer in one box at £15.50: a 1-litre wide-mouth jar, a silicone valve lid, ceramic weights and a recipe booklet.
The traditional route and the only opaque vessel here: a 2-litre stoneware crock with weights and a pounder for £37.98.
The cheapest entry at £8.55 and pure consumable: ten sachets of EC-1118, each dosed for a batch of 4.5 to 23 litres.
The same idea as rank 4 for a pound less: four 7 cm glass weights with a grip handle and a gap cut in to let excess brine out.
Two 1.4-litre jars with one-way airlock lids for £11.99 — and the sharpest price move on this page, up 35% over the observed period.
The dedicated kefir vessel and the natural partner to the live grains at rank 2: a 900 ml jar with a strainer lid and an airflow cover.
| Product | Score | Stars | Reviews | Feature | Material | Price | Offer |
|---|---|---|---|---|---|---|---|
| 01. Coravin Argon Capsules, 6-pack Best seller Coravin · Coravin |
9.4 | 4.6 ★ | 3,579 | 6 capsules · argon | Steel capsules | £51.99 | Amazon › |
| 02. Kombuchaorganic Live Milk Kefir Grains, 10 g Kombuchaorganic · Kombuchaorganic |
8.8 | 4.3 ★ | 2,385 | 10 g · live grains | Live kefir grains | £9.99 | Amazon › |
| 03. 25 Litre Plastic Bucket with Lid PLAST SERVICE PACK · PLAST SERVICE PACK |
9.0 | 4.4 ★ | 2,348 | 25 L · lid + handle | Plastic | £13.24 | Amazon › |
| 04. Country Trading Glass Fermentation Weights Country Trading Co. · Country Trading Co. |
9.0 | 4.6 ★ | 1,076 | 4 weights · glass | Glass | £12.99 | Amazon › |
| 05. Kilner 1 L Fermentation Jar Set Kilner · Kilner |
8.9 | 4.4 ★ | 1,833 | 1 L · valve lid | Glass | £15.50 | Amazon › |
| 06. Kenley Stoneware Fermentation Crock, 2 L Kenley · Kenley |
8.8 | 4.4 ★ | 1,328 | 2 L · stoneware | Stoneware | £37.98 | Amazon › |
| 07. Lalvin EC-1118 Wine Yeast, 10 x 5 g Lowest price Lalvin · Lalvin |
9.3 | 4.6 ★ | 2,769 | 10 sachets · 5 g | Dried yeast | £8.55 | Amazon › |
| 08. volila Glass Fermentation Weights, 4-pack volila · volila |
8.3 | 4.3 ★ | 470 | 4 x 7 cm · glass | Glass | £11.99 | Amazon › |
| 09. volila Fermentation Jars 1.4 L, 2-pack volila · volila |
8.3 | 4.3 ★ | 469 | 2 x 1.4 L · airlock | Glass | £11.99 | Amazon › |
| 10. Kefirko Kefir Maker Starter Kit, 900 ml Kefirko · Kefirko |
8.6 | 4.3 ★ | 1,073 | 900 ml · strainer | Glass | £28.99 | Amazon › |
A ferment produces carbon dioxide for days. A fermenting lid lets it escape without letting air back in — a silicone valve, a one-way airlock or the water moat around a crock rim. A clamped preserving jar does none of that and builds pressure instead.
Anything floating above the brine line is where mould starts, which is why two of the ten listings here are nothing but glass discs. Match the weight diameter to the jar mouth: 7 cm weights only drop into a wide-mouth jar.
A jar of kimchi wants 1 to 2 litres. A demijohn of wine or a bucket of beer wants 23 to 25. Both live in this subcategory and they are not the same hobby, so read the capacity before the price.
Live kefir grains and yeast sachets are dated goods, and the grains here ship directly from the seller rather than from Amazon stock for exactly that reason. Order them when you are ready to start, not weeks ahead.
Glass lets you watch the brine line and the bubbles, which is how beginners learn what normal looks like. Stoneware keeps light out and hides everything. A food-grade plastic bucket is the cheap way to get to 25 litres and nothing else.
Packing cabbage in and pulling weights out both need a wide mouth. A narrow-necked demijohn is for liquid ferments where nothing solid ever has to come back through the opening.
They look alike and work in opposite directions. A fermenting jar has to vent carbon dioxide through a valve or airlock while keeping air out. A preserving jar is filled hot and sealed so it pulls a vacuum as it cools, and is meant to stay shut. Clamping a live ferment into a preserving jar is how lids get pushed off — the preserving jars are a separate page here.
Amazon files the Coravin capsules in this subcategory, and they earn more than anything else in it. They preserve an opened bottle of wine by keeping air away from it, which is roughly the opposite of fermenting. We leave the listing where the data puts it and say plainly what it is.
For vegetables, yes: sauerkraut and kimchi spoil from the top, where anything lifted out of the brine meets air. Weights are the cheapest insurance in this list at around £3 a disc, and two of the ten entries here sell nothing else. Liquid ferments such as kefir and wine do not need them.
The products are ordered by estimated monthly revenue per ASIN, not by star rating and not by bestseller rank. Only products with at least 200 reviews and an average of 4.3 stars were included, which is why a bucket and a bag of yeast can outrank purpose-built fermenting kit.
The score is not our own hands-on test. It is calculated transparently from public Amazon data: 75% from the average star rating and 25% from the number of reviews, weighted logarithmically. The ranking order itself comes from estimated monthly revenue per ASIN. Prices, ratings and review counts were retrieved from Amazon.co.uk on 22 July 2026 and can change at any time.
Affiliate disclosure: As an Amazon Associate we earn from qualifying purchases — at no extra cost to you. All links are affiliate links. Prices are snapshots taken on 22 July 2026; the current price is shown live on Amazon. Product images and details come from Amazon or the manufacturers.