Liquid Malt Extract or LME as it is sometimes called is a thick, viscous, treacle like liquid that is made from malted barley and is the basis of a beer kit.
Let's start by explaining the process to make beer. I'll then explain the differences and that will hopefully explain what liquid malt extract is and how it can be used and what is different in a beer kit and how you can use LME to enhance a beer kit.
How To Make Beer
To make beer, you take your grains - usually barley - and some other grains to add colour and flavour, then steep these grains in water at between 60°C - 69°C for around and hour. Different temperatures create slightly different sugars which can affect the sweetness and mouthfeel of the finished drink.
An enzyme in the malted barley (it's the same one as starts the root to grow in a seed) starts breaking down the starches in the malted grains and starts turning the starch to sugar which dissolves into the water.
This process is called mashing and at the end of the mash you have a sweet liquid called Wort.
The grains are no longer of any use, so they can be fed to the birds, be put on your compost heap or if you know a farmer, the cows and pigs will love it.
So we now have a sweet liquid. Now normally when making beer, you would add hops and boil the wort for an hour to infuse the wort with the bitterness and aromas from the hops.
Once the boiling is finished, you then quickly cool the wort to 20°C and pitch your desired yeast.
At home, this whole process usually takes between 6-8 hours depending on your set-up.
How a Beer Kit Is Made
Basically the makers of the beer kit make the beer to their desired recipe as in the process above.
The wort is put into a huge tank (called an autoclave), it is heated and at the same time the air is removed to make a vacuum. This means the water boils off at a lower temperature.
Did you know if you were to boil water on the top of Mount Everest, it would boil at just 68°C not the usual 100°C we are used to at sea level. That's because there is less air pressure and the same happens to the wort.
Boiling the water off at a lower temperature helps prevent extra colour and flavour being imparted due to the Maillard effect and helps to retain its delicate aromas the hops have added.
The beer kit is now a thick treacle like goo. It has all the ingredients used to make the beer concentrated, so all you have to do is add water, bring it to 20°C and pitch the yeast.
So when you add back the water, it has the sweetness and bitterness and the aromas from the hops just as if it had never been concentrated and you have made the beer from scratch like in the How To Make Beer Process.
Liquid Malt Extract
Now there isn't much difference between a beer kit and pure Liquid Malt Extract.
Basically, in Pure Liquid Malt Extract, they steeped the grains so the enzyme could turn the grains starch to sugar and then concentrated it in the vacuum autoclave. That's it!. They have not added any hops and they did not boil it for the extra hour. So it is just a sweet thick malty, sweet goo. Mmmmm
You can use a can (or a pouch) of liquid malt extract just like you would a beer kit and you can even make up your own recipe, adding your own hops, adding yeast and come up with something unique.
There are some major beer names that buy in liquid malt extract and then add their own hops to make some very well known lagers so it is a very easy way to make your own beer.
You can use pure liquid malt extract to make a drink like Horlicks, you can use it to make honeycomb, you can use it to make Maltesers, OMG, using it in a Malteser cheesecake to make it really malty is amazingly delicious and moorish.
Here's my favourite Malteser Cheesecake recipe - https://www.janespatisserie.com/2015/05/29/no-bake-chocolate-malteser-cheesecake/ - It actually calls for Malt Powder - more on Malt Powder below. Tip: add some malt powder to the whipped cream too!
Liquid Malt Extract comes in lots of different options. Light, Amber, Dark, Oat, Wheat, Hopped, etc, etc. This is so you can customise your beer making if you are using just the extracts to make beer or if adding them to a kit. Just like the beer kits, the maker of the LME has added extra grains to the base malted barley to add extra flavour and colour to the LME.
E.g. 1 - You could take a tin of Hopped Dark LME and a tin of Oat LME and put them in a fermenter, top up to 23 litres and add a yeast good for a stout and in a couple of weeks you'll have a Breakfast Stout at about 5% ABV.
E.g. 2 - You could take a tin of Oat LME and a tin of wheat LME and top up to 23 litres, using a yeast like Mangrove Jacks M66, adding 50g of Citra hops while it is fermenting, then on day 7 adding another 100g of Citra hops and leaving them for 2 days and you'll have a hazy, full bodied, Citra aromatic craft beer.
The rule of thumb with Muntons Liquid Malt Extracts is 1kg of LME to 8.5l of water will make a beer around 5% ABV.
Adding Liquid Malt Extract to a Beer Kit
Some beer kits need extra sugar added. This is because in the beer making process, they did not use enough malted barley in the recipe to get to the desired ABV, so you need to supplement it with extra sugar. These are usually single tin or pouch beer kits of 1.5kg to 1.8kg.
Just using sugar can make the finished beer a little on the thin side. Great if you like a light beer.
But if you want your beers to have some body, then swap out the sugar for liquid malt extract.
Do not try doubling up the beer kit, so using 2 instead of 1, as this will also double the bitterness and make it quite difficult to drink as it would have twice the amount of bitterness of a normal beer.
So this is where the pure liquid malt extract comes in handy. You can add it to a beer kit that calls for extra sugar, to add extra body, mouthfeel and sugar for the yeast to eat to get it to the desired ABV.
You can add which ever tin of LME to the beer kit that needs sugar and create your own unique version of that beer. Just use Pale Malt, or want some extra colour, use the Amber LME, want to turn it even darker, add Dark LME. Want a smooth beer, add Wheat LME. Want a creamy mouthfeel, add Oat LME. So many different options.
Perhaps you are making a Youngs Harvest Lager, why not add some Vienna Malt Extract to the kit and turn your finished lager into a Vienna Lager, a slightly darker colour with a light toasted and biscuit flavours to create a rich lager.
The options are endless.
Unfermentable Sugars
In the beer making process, when we were using the enzyme to turn the starch in the grain to sugar, well some of that sugar that is created is not able to be eaten by the yeast (non-fermentable). This is why beer has a slight sweetness even when it has fully fermented.
Adding more liquid malt extract to a beer kit that calls for extra sugar, will have some more non fermentable sugars, so will have a bit more sweetness that if you have used sugar.
But if the beer kit had been made with the grain needed to make the ABV, then it would be that sweet naturally. So you are making an authentic beer.
Powdered Malt / Spray Malt
Now there is another version of Liquid Malt Extract that has been even more concentrated.
This is usually called Spray Malt or Powdered Malt.
The process is the same to make as the liquid malt extract, but instead of letting the water boil off, they spray the wort through fine jets to make a fine mist into a vacuum.
The water instantly evaporates and leaves the wort as a powder.
This powder must be kept away from the air, as the tiny amount of water in the air will be sucked up by the powdered malt and before you know it, you have a gooey sticky mess.
It's takes up less room than the tins of LME and its easier to transport and it's just as easy to use and you can add it to a beer kit in the same way as LME and OMG it works amazing in that cheesecake recipe I mentioned above.
Just use this as you would sugar. So where a beer kit calls for 1kg of sugar, then replace it with 1kg of Spray Malt. The finished beer will taste amazing.
Conclusion
So Liquid Malt Extract is what makes up the base of a beer kit, and the only real difference is that a beer kit has been made to a recipe and had the hops already added.
