A few people have been PM'ing me on my partial mash method. To avoid re-posting it all over the place, I thought that I'd put the information in this topic and if required, the mods can make a sticky out of it...
When I moved from kits and steeped grains to mini mash or partial mash brewing, I didn't have all the fancy brewing equipment such as a Mashtun, Hot Liquor Tank, 50L Kettle and Chiller. Besides, I didn't want to spend a heap of money and find out that it wasn't to my liking.
So I did a partial mash using basic equipment found in most kitchens. To use my method, you need the following equipment:
- Two large pots - one to heat up the brewing water and one for the boil
A esky of at least 6-pack size,
A mesh colander or strainer,
A handheld thermometer, and
A soup ladle.
For the purposes of this post, I'll overlook the recipe and grist, but assume that you have base malt that needs to be mashed in, to allow the amylase enzymes present in the base malt to convert the hydrolised starches present into fermentable sugars.
So, here's my partial mash in the kitchen method:
Half fill the mini / 6 pack esky, with 74C water that's been pre-heated on the stove.
Gradually pour in all of the grains (er, after you cracked them of course!), stirring gently as you go. You eventually want the mixture to have the consistency of soft porridge and a temp in the esky of around 66C - use the coffee kettle or cold water tap to adjust but it's not the end of the world if you're a few degrees either side of 66C. Keep an eye out for doughballs that are easily made in a small mashtun such as this - you need to ensure that all of the grist is soaked with mash water and you don't have any dry spots in the mashtun that will result in poor efficiency and unwanted starch haze in the final product.
Cover the mash and let it sit for 60 mins, stirring every 15 minutes - ignore the inevitable temperature drop - most of the conversion will occur in the first 30 mins anyway.
Whilst you mash for an hour, clean the primary fermenter and if you're using dry yeast, proof it in a clean cup...
Because we're mashing and not steeping, you need to watch your temps. The temperature of the mash will determine which of the two starch to sugar converting enzymes have the most influence on your mash - a mash between 60 to 65C will result in a more fermentable, dryer beer whereas a mash between 65 and 70 will deliver a more malty / dextrinous and fuller tasting beer. I tend to hover around 66C for dry stouts. If your mashtemp is looking like falling below 60C, add around 250ml of near boiling water and gently stir through to disperse the heat - it should bring the mash back up to the 66C mark - repeat if necessary.
As you near the end of the one hour mash, heat about 3L of water to 70C. Place a colander or fine sieve over the second pot (which will be the boil kettle - I used a 12L stock pot). Gently ladle a few scoops of the grains, that have been mashed for an hour, into the colander from the mash esky and drizzle 300ml of 70C hot sparge water over the grains allowing the sweet liquor to accumulate in the stock pot kettle. Eventually you should have collected around 4-5L of sweet liquor (remember we half filled the mash esky and heated up 3L of sparge water). ((Optional: I used to collect the sweet liquor in a vessel and decant it from that vessel into the brewpot via a 1L jug and a muslin bag which would trap the find particulate matter when you poured the sweet wort through it)).
Once finished, you can boil that sweet liquor with half your hops in that pot and use the now empty hot water pot to boil up the extract in your recipe with the other half of the hop bill in about 3-4 litres of water. To add bitterness to the boiled wort, you should boil for at least 30 minutes. I recommend a gentle 60 minute boil. ((Optional: If you have a large enough pot, do a single boil but make sure that the sweet wort combined with the malt extract is topped up to a pre-boil volume of at least 12L otherwise you loose a lot of hop bittering potential with a high gravity boil such as this.))
Note: If you are using a pre-hopped kit as well as extract and grains, you want to keep the hop flavours in the kit so don't add the kit to either boil. The kit can be added to either pot when they are being chilled in the sink. If you add a kit to a boiling wort, all your doing is knocking out the heat sensitive hop aroma and flavour compounds...
When the boil has ended, take the pots over to the sink and fill the sink with cold water - gently stir the wort to whirlpool in one direction and have the outside sink water moving in the opposite, or counterflow, direction to improve the heat exchange. Change the sink water frequently and you'll eventually get the wort below 25C. Splash pour into the fermenter, check temperature and pitch yeast. Seal the fermenter and you're done...
In terms of hygiene, the boil does a pretty good job of holding the bacteria at bay. Just remember that once the boil is over, your wort is vulnerable to infection so make sure that anything that's in contact with the post boil wort (such as your thermometer and destination fermenter) is clean and sanitary...
This method is pretty straightforward and lets you transition to all grain brewing by simply increasing the size of your mashtun...I hope this helps.
Cheers,
TL
) but im pretty happy with how it went and is really no harder than doing an extract with specialty grains......looks like its going to be AG for me as soon as i can get the gear together 