Brewing Beer From Malt Extract
If you want to progress beyond making beer from kits, but don't have the time, or equipment to brew from grain, then extract brewing is a great way to start brewing to your own recipe. Extract brewing has the advantage that you don’t need very much equipment and is generally faster than brewing using grain.
A second advantage of brewing with malt extract, is that even if you are brewing a standard 5 gallon (23 litre) batch, you don’t actually need to boil this volume of liquid; you can boil up as little as 1 gallon (4.5 litres) and simply dilute the wort before adding the yeast. This means you can actually use quite a small pot on your kitchen stove, without much trouble. Bringing 5 gallons of wort to the boil not only requires a very large pot, it would beyond the capabilities of most hobs!
Equipment needed for extract brewing
If you already brew beer from kits, then you probably already have much of the equipment you need, i.e a fermentation vessel with airlock, hydrometer & trial jar and some siphon tubing. In addition to this, you will need the following:
- Large saucepan or stock pot (suggested size 10-15 litres)
- Measuring jug
- Kitchen scales
- Rice strainer / colander
- Muslin hop boiling bags
- Immersion chiller, plate or counter flow chiller
Principles of brewing beer
Beer is made by soaking malted barley in hot water to extract the sugar, then bringing this sweet liquid, called wort, to the boil along with hops. Hops have several purposes; they add bitterness, flavour and help to preserve the beer, as well. Hops added at the start of the boil will add bitterness, while hops added towards the end, or even after the boil has completed, will add flavour and aroma. Hops added in the middle of the boil will contribute both bitterness and flavour, but in smaller quantities.
Hops can even be added after fermentation has finished, which adds even more aroma and some additional flavour. This process is known as dry hopping.
A beer’s bitterness is determined by how many grams of hops are added, at what point in the boil they are added and the percentage of Alpha Acids the hops contain. The higher the percentage of Alpha Acids, the more bitterness a hop will provide. Flavour and aroma will predominantly come from hops added in the later stages of the boil and will depend on the amount and type of hops used.
Once the boil is complete, which usually takes 60-90 minutes, the liquid (wort) must be quickly cooled, to 26°C or lower, so that the yeast can be added (pitched). Yeast requires a good amount of oxygen to be dissolved in the wort, in order to reproduce. However, during the boil, most of the oxygen is driven off. It is therefore very important to aerate the wort, before pitching the yeast, by either stirring vigorously for several minutes, or pouring the cooled wort and any additional water, into the fermenter from a good height.
Once the yeast has formed a large enough colony, it will then start to ferment the wort, converting the malt into alcohol, producing Carbon Dioxide (CO2), as a by-product. The CO2 rises to the surface, creating a foam (called Kraüsen) on the surface. After a few days, fermentation slows down, the foam subsides and the bubbling or even stop, although it may take a week or more for fermentation to complete.
If you plan on dry hopping, hops should be added once fermentation has stopped, otherwise the CO2 bubbling out of the beer, will take all of the hop aroma with it. Dry hopping should be done for 3-4 days before bottling or barrelling.
Using Malt Extract
In beer brewing, barley grains are soaked in very hot water for an hour or more, to convert the starch inside the grain to sugar (maltose), in a process called mashing. The grains are then washed (sparged) to release the sugar and this sweet liquid is then called wort.
Using malt extract means you as a brewer skip the mashing and sparging steps, you simply need to add water to the malt extract to make a wort and bring that to the boil.
Due to the water content of liquid malt extract, you will need 20% more liquid extract in a recipe than you need dry extract. You can use either type and will see almost identical results.
There is generally a wider range of dried malt extracts, such as extra-light, light, medium, dark and extra dark, as well as wheat and hopped extract. Liquid malt extract generally only comes as light, medium and dark, but you can always use a combination of dry and liquid extract to achieve the exact colour and flavour you require.
Boiling the wort
Unless you have a very large pot, or boiler, with the ability to bring five and half gallons of liquid to the boil, you will generally be boiling a much smaller volume. Two gallons (nine litres) is a good compromise, as the pot size is easy to handle and the wort will come to the boil quite quickly.
However, it is important not to add too much extract at the start of the boil, as this will lead to a very-high gravity wort, which decreases hop utilisation.
What this means is that the amount of bitterness and flavour extracted from the hops, decreases as wort strength increases. Because of this, you need to scale back how much extract you add at the start, then add the rest of the extract about 10 or 15 minutes before the end of the boil.
If you use some brewing software, such as Beer Smith or Brew Target, you will be able to see how the amount of extract you add will affect the IBUs (bitterness), but if you don’t use these tools, then the following amounts should work, based on a 23-litre final volume going into the fermenter:
- 5 litre boil – 500g dried, or 600g liquid extract
- 10 litre boil – 1kg dried or 1.2kg liquid extract
- 15 litre boil – 1.5kg dried or 1.8kg liquid extract
When adding extract, always remove the pan from the heat, or if using a boiler with a built-in element, turn the heat off and stir rapidly. This will stop the extract from caramelising or scorching on the bottom of the pan or boiler.
Hops provide a beer with bitterness, flavour and aroma. The amount of bitterness will depend on how many hops you use, how long you boil them for and the Alpha Acid level of the hop. The higher the Alpha a hop has, the more bitterness it will provide.
In addition, bitterness is only really achieved when the hops have been boiled for at least an hour, so the less time you boil a hop, the less bitterness it will contribute, adding flavour and aroma, instead.
Some hops are suited to bitterness, others to aroma, while others are dual-purpose and can be used for bother bitterness and aroma. If you are new to brewing, it is advisable to follow a recipe or use brewing software to create a recipe, otherwise the quantities of hops you use and the boil time will be guesswork and could lead to disappointing results.
Hops can also be added at the end of the boil (steeping) or after fermentation has finished (dry hopping). Both of these techniques add even more flavour and aroma to your beer.
About 15-minutes before the end of the boil, you will need to add the remainder of the malt extract. Remove the boiler from the heat and slowly add the extract, stirring all the time. Once all the extract has been added, bring back up to the boil. Once the wort is back up to a rolling boil, add some Irish Moss.
Once you have boiled the wort for the remaining 15 minutes, turn off the heat. At this point you can do a steep – adding extra hops for 15-30 minutes, but if you do this, put a lid on the pot to keep any nasties out.
Cooling the wort
Before transferring to your fermenter, you will need to cool the wort down. Adding cold tap or bottled water in the fermenter will help, but either use a wort chiller, or put the pot in an ice bath to cool it down rapidly to under 26°C, so that you can pitch your yeast. If you use an ice bath, ensure that there is a good lid on the pot, during the cooling process.
Transfer the cool wort to a sanitised fermenter and top up to 23 litres, or whatever volume your recipe calls for. You can either siphon the wort out of your boiler (ensuring the siphon is sterilised first), or pour the liquid through a rice strainer or colander, into the fermenter.
If you siphon, leave behind the hops and any solids at the bottom of the boiler. If using the pour method, the hops in the strainer or colander will act as a filter bed, keeping the solids out of your fermenter.
Once the wort has been transferred and topped up to the correct level, take a hydrometer reading to ensure you have met your target gravity. If you are too high on the gravity, you can add water, if you are too low, you will either need to live with it, or add some more extract, which you will need to boil first, to sanitise it.
Check the temperature of the wort in the fermenter is below 26°C and pitch the yeast. Fit the fermenter lid and airlock, if you are using one and allow to ferment for 10-days to two weeks. Use your hydrometer to ensure that you have reached final gravity (1.010 or below), before moving on to the bottling or barrelling stage.
If you are dry hopping, add the hops 3-4 days before bottling or barrelling.
That’s it, you've just brewed your first beer from Malt Extract!
I hope you found this guide useful, you can find all the ingredients, additives, fermenters, etc. in the beer-making section of the web site.