A couple weeks ago I was invited by the iconic British condiment company, Sarson’s, to have a look around their factory and see the process of vinegar-making. They contacted me as they had noticed my little blog and thought I might be interested in seeing what they do because they make vinegar in the traditional way; and we’re all about tradition here at British Food: A History.
The word vinegar comes from the French words vin meaning wine of course, and aigre meaning sour or sharp, so when we talk about British malt vinegar, it’s actually a bit of a misnomer. What is in your bottle of Sarson’s used to be called alegar: sour ale! I think the word should be brought back (I’ll pop a note through to Mr and Mr Sarson).
Vinegar – aka ethanoic or acetic acid – is produced when specialist bacteria called acetobacteria metabolise normally deadly alcohol (ethanol) and harness energy from it. It takes a real specialist to use this killer chemical as a food source. Vinegar is, of course, an excellent preservative itself.
It is thought that vinegar and alcohol fermentation were discovered and refined in tandem, and the earliest example of vinegar-making goes right back to the ancient Babylonians who were brewing it from their beer and wine in 4000 BC! The ancient Romans refined methods somewhat, using wooden barrels to age and develop flavour.
The rear of the original London factory (Southwark Local Studies Library)
There are there are many types of vinegar, but malt vinegar, which is made from barley, is uniquely British, although these days it does travel a bit. Barley was a very important crop in Britain as it was grown to eat, but also to make ale. The average person in mediaeval England would drink around a litre of ale a day and it was the main source of calories for many (and much safer to drink than the water). Our love of ale meant there was plenty spare knocking about to transform into alegar. Sarson’s are the only company still making it in the traditional way and they have been producing it since 1794.
Before I had even arrived, I was greeted a delicious sweet and sour malt smell, and when the taxi pulled up outside the Manchester factory I was greeted again by the lovely folk who run the place. I donned my lab coat, safety glasses, hard hat and beard snood, and looking altogether pretty damn sexy I headed over the see the initial steps in the process.
I had always assumed that when malt vinegar was made, ale would be bought in and then fermented, but this is not the case! Sarson’s do the whole process from start to finish, including making the ale itself. It is truly made from scratch.
The first step is to lightly mill the barley so that the grains can crack open. It is then soaked in spring water and heated up in mash tuns: huge metal vats that constantly stir the barley and the water is collected. This process of mashing extracts the sugars.
Swishing away the sweetwort
I was allowed a little taste of the sugary liquid – or sweetwort – and couldn’t believe how sweet and delicious it was (when I got home, I looked in a few old books and found that home-made barley water was produced in essentially the same way).
The cooled sweetwort now enters the first round of fermentation: yeast is added so it can get to work anaerobically turning sugar into alcohol. This six-day process produces a barley ale that is a whopping 9.5% alcohol.
Now the alcohol can be converted into vinegar in the second round of fermentation. It was this part of the process that I found to be truly amazing: I assumed that to make a product and attain perfect consistency between batches, Sarson’s would have to seed the ale with a mother (or mother-of-vinegar to give her full title, a of plug acetobacteria) that had been carefully selected over years or even decades, to produce a unique strain (wine and beer makers do this with their yeasts). What Sarson’s actually do is simply add the shavings of the bark from the larch tree, which naturally harbours a community of acetobacteria species. This all happens in wooden tubs called acetifiers and it takes seven days for the larch bacteria to do their magic.
The huge physics-defying oak barrels!
For the last stage, the vinegar is stored in huge 40 000 litre barrels – some 100 years old – to be standardised to the correct strength (5% ethanoic acid).
Standardising the final product
The vinegar is heated up to kill the bacteria and it is piped through to the very noisy and exciting bottling room. I loved watching the bottles rattling around on the conveyor belts. It was as though I had literally stepped through the arch window on Playschool!
Then, to top it all off, they handed me my very own personalised bottle of malt vinegar!
Many thanks to Sarson’s for asking me to come to their place and let me be a nosey parker for an afternoon – I will certainly be paying the malt vinegar I put on my fish and chips in even higher regard from now on!
Next post, I’ll write a little bit about how we use – and used vinegar in the home.