Fermentation Station

One of the things we have found ourselves with recently is more time. And as the old adage goes, with more time comes more fermentability.

Whether it's sauces, fruits, chillis, or even potatoes, there are often fermentation jars on the go around our kitchen,and we've stepped it up a gear in the past couple of months. So this is a little round up of our little fermentation projects, with some ideas of flavour combinations and some techniques that anyone can have a go at.

Fermentation is essentially a way of preserving perishable foods by encouraging the growth of bacteria to lower the pH, increasing the acidity. The bacteria, while wild in this case, are the same that occur in live yoghurt - lactobacillus. They're literally everywhere, just floating around nonchalantly constantly on the search for something upon which to feed. Here, we are encouraging the lactobacillus by reducing the activity of other wild yeasts and bacteria with salt. It may feel like a lot of salt sometimes but by the time it's ready to eat, the acidity will have picked up and the flavours of fermentation will have balanced the salination.

Our first top tip would be to use decent salt, not table salt as it has anti-caking agents and can be iodized, which will inhibit bacterial growth. Opt instead for sea salts (we're Maldon fans), or if you're made of gold you may want to give Himalayan salt a try (although the mineral benefit is largely bullshit). Generally speaking, everything needs around 1.5-2% salt by weight of your base ferment.

Also worth mentioning for beginners, that the process of fermentation involves the creation of gas. You need to get yourself an appropriate fermentation jar (Kilner jars are good), and "burp" your little bubbling babies every day for a week or so, and then every other day until you see no more release of gas. This will help to prevent stinky explosions.

Here's a few simple ideas to get you started...

Beer vinegar 

For this, you'll need a vinegar mother. Live vinegar (which means it includes a mother) can be bought in most supermarkets, and flocculates (settles) easily. If you leave a bottle to settle overnight and decant the clear vinegar off, leaving the sediment behind, this is the mother. Splitting this between around 400ml of "food" will work well. The food can be anything with a little bit of sugar left. A bit of "leftover" wine or cider, or the last bit of that minikeg that you've bought because you can't go to the pub, all work well.

The vinegar will start to sour quickly - over a couple of days to a week - and you can start using it at this point, but leaving it to mature for a month or longer will intesify the flavour.

As you start to produce vinegar, the mother will munch on the sugar and carbohydrates you feed it and will grow, allowing you to eventually produce more. This will help your brine fermentations by pitching a little hither and thither.

Beer pickled onions 

Onions
Salt (1.5-2% onion weight)
Brown sugar (5% onion weight)
Beer:Vinegar (60:40 - enough to cover the onions)

Any onions can be used for this, but I like something a little more interesting - if you can get some little silver skins, some shallots or rings of red onion then go for it. To prep the onions, first peel them, halve them (and if they are larger onions I like to quarter them) but leaving a 2cm join at the root end. this allows them to pickle quickly and evenly, but helps the onion retain its structure. Weigh your onions and calculate your dry additions. Dissolve them in a little beer (we used a pale ale - don't go for anything too hoppy, but anything with a bit of sweetness or something saison-ny would work well... we're going to try a stout next!) and pour over your onions in a jar, topping up with more beer and vinegar to cover - the above ratios are approximate so just use whatever you have available. It'll take around 5 days to start softening the intense raw onion flavour, but will develop nicely over a month.

Served simply with a hunk of cheese and a generous slice of bread, these are delicious.

Kimchi

Cabbage or Chinese greens
Gochuchang (between 1tsp and 1tbsp per 200g of cabbage by weight, depending on how spicy you like it)
Salt (1.5% by cabbage weight)

Optional extras (per 200g of cabbage)
Spring onion - 1 finely chopped
Ginger - a thumb, either grated or jullienne
Garlic - 3-6 cloves crushed or chopped
Chillies - 2-4 chopped
Fish sauce - a good glug or two

First, weigh the greens so you can calculate how much of the other ingredients you need. Chop the cabbage into ribbons or if using Chinese greens, such as Pak Choi, into quarters. Take the salt and rub it into the leaves and all the nooks and crannies of your chosen veggie. Set to one side for around 15 minutes, while you mix the gochuchang and optional additions together.  At this point thoroughly rub the sauce into the leaves. Simply jar it up and leave for a week to a month for all that funk to come through.

I like to keep topping mine up with fresh cabbage - just give it all a good stir and the leaves that have been in longest will start to soften and break down, with the fresh taking on all the flavour and adding a pleasing crunch. A bit like a Kimchi solera system.

Garlic and Ginger

50/50 garlic/ginger chopped loosely
Salt

Mix everything together, leave for a few days until the aroma intesifies and then blitz.
You can then smosh into any food that needs garlic - it's great to fry off as the base of curry and stir fry, or toss into some fried prawns with a little lime juice. Or perhaps the base of herb pesto, warm through with some olive oil and toss into pasta.

I have really enjoyed using this paste - the garlic really intensifies but also rounds out with the fresh spice of the ginger, as well as having the added advantage of convenience from a jar. It HONKS but it's so worth it. Ridiculously easy too.

Pickled Chillies

A bushel of chillies
Salt (1.5-2% of weight)
Water to cover the chillies in the jar
Vinegar culture if you have one, just a splash

There is no skill involved in this whatever, just throw it all together in a jar, shake to dilute the salt and leave for a couple of weeks to pickle. Consume. Perhaps on a Ploughman's lunch, chopped into a rarebit, or chopped into butter to top a naan bread with. Basically anywhere you fancy a little bit of heat, these guys are there to help.

Green Tomato Ketchup

Green tomatoes
Salt (1.5% of the weight of the toms)
Sugar (10% weight)
Chillies
Black pepper

Roughly chop the tomatoes, into halves, quarters, whatevs. Chuck everything in a fermentation jar and cover the now salty, sweet and spicy toms with water, seal and then shake. Loosen off the jar to allow for fermentation and leave for 3-5 days. Then, blitz everything until smooth - the skins and the pulp shouldv'e broken down a little, but after blitzing give it a taste. More chilli or black pepper could be added, but the acidity will continue to build after the blending so no need to vinegar.

Fermented potatoes

Inspired by Brus in Copenhagen, where we ate fermented fries with mushroom ketchup nearly three years ago. We still think of them daily.
Potatoes
Salt (1.5% of the weight of the potato)
Water
Garden herbs (we use a lot of rosemary)

Chop your potatoes, chuck everything in a jar and leave it for a bit. While initially it may seem odd, this is totally worth it, whether you opt for brining overnight before frying off potatoes for a breakfast hash, or going for a longer ferment on a roast potato for a Sunday dinner, this process really intensifies the flavour and firms up your spud. They are splendid after 3 days, oven roasted for an hour at 180C with a nob of dripping.

Once you've embarked on your first few projects and you are happy with the way your ferments are tasting, then why not chuck a little bit of a similar base into your next batch?
Beer vinegar -> pickled onions -> ketchup

All of thes ideas above are interchangable, blendable and pitchable. If you are really happy with the flavour profile of something, sacrifice some of it to the next batch rather than shoving it all on the next toastie, however tempting that may be. Future you will be grateful.

Let us know what you try, and happy fermenting!

Jim