Intermediate Extract Brewing - Partial Mash

Partial Mash with Extract Brewing 

 

Extra Equipment Needed:

  • Nylon/Mesh Grain Bag
  • Ice Bath
  • Wort Chiller (optional)

A partial mash is a great next step in extract brewing for when you are feeling more comfortable with the brewing process. This technique involves collecting additional fermentable sugars into your wort from crushed grain that will impart original flavour and aroma into your brew. It allows for more complex flavour profiles and you can create a wider range of beers using various specialty grains.

A partial mash is fairly simple and does not require many extra pieces of equipment outside a standard Mangrove Jack’s Starter Kit or your current home setup. Mashing is essentially soaking the grains in water in order to dissolve the starch transforming it into sugar creating your wort.

 Recipe:

The recipe we will focus on will be an American Pale Ale Partial Mash.

You will need;

 

Method:

  1. Clean and sanitise all your equipment like normal.
  2. Heat 11 L (2.9 US Gal) water for the grains in a large pot (preferably 20 L (5.3 US Gal)) to 65°C (149°F). This is what’s referred to as the ‘strike water’ and is what the grains will be mashed in.
  3. Place your grains into a nylon/mesh steeping bag. You can either leave the end open and draped over the pot which makes it easier to stir the grain, or simply tie it off at the end if this is not possible.
  4. Lower the bag into the pot and saturate, making sure there are no dry clumps.
  5. The temperature should now be around 10°C lower than before and this is where we want to keep it for around 30-minutes for the grains to mash in with the pot lid closed. It’s definitely best to use a gas stove so you can keep the temperature stable for this time.
  6. After 30 minutes remove the lid and stir the grains if possible. Then lift the bag up out of the pot and let the remaining liquid from the bag drain into the pot as you hold the bag above it. This is called lautering.
  7. If it is possible you can attempt a ‘sparge’ which involves rinsing the grains with fresh 65°C water. This is much easier if brewing with a friend as they can hold the bag open for you. This technique will ensure you rinse as much of the sugar off the grain and into your wort as possible. Just use a small amount of water here, no more than 1 L (1 US qt)
  8. Next add half the Mangrove Jack’s malt extract from the pouch or can, stir it in until completely dissolved.
  9. Now start bring the wort to a rolling boil as long as bubbles are breaking the surface this is enough.
  10. Once you have reached a rolling boil you can choose to add a ’60-minute’ bittering hop addition. Hop additions in this fashion are labelled with the time remaining until the end of the boil.
  11. Boil for 50-minutes, then add the dextrose and remaining extract from the kit and stir.
  12. Allow to boil for the remaining 10mins
  13. Turn off the heat and add your late aroma hop addition.
  14. it is time to chill the wort as quickly as you can to around 50°C (122°F). There are a few ways of doing this, the easiest to achieve is to take the pot and place it in a bathtub full of ice, but be warned this is not always the safest option as moving a vessel with near boiling liquid inside can be hazardous. The other option is to purchase and use an immersion chiller, which consists of a spiral of copper/stainless steel that is connected to a cold water tap and then placed inside the pot. As water flows through the chiller it cools the metal, which then cools the liquid it is sitting in. The rate at which is cools is dependent on the cold-water temperature, but you can also slightly stir the wort to increase cooling efficiency.
  15. Other tips for using an immersion chiller: Most will require an adapter to connect to a standard kitchen tap, you can get these at your local homebrew supply store or potentially a hardware store. To easily sanitise the chiller before you put it in the cooling wort, add it in the final 15-minutes of boiling. It is then ready to chill straight away when needed.
  16. Now top up the fermenter to 23 L (6 US Gal) with cold water and let cool to below 26°C (79°F).
  17. Once the wort has cooled, transfer it into a clean, sanitised fermenter. Take a hydrometer reading, then rehydrate and pitch your yeast.

The rest of the process you will be familiar with, store your fermenter correctly and monitor the fermentation process for a week. We are aiming for a final gravity of 1.015. When ready it’s time to bottle and with a little more patience it will be time to drink your delicious partial mash brew!

We also have Partial Mash kits available in select home brew stores – so request yours today. Click HERE for more information.

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