Partial Mash Simplified
This guide is written for extract brewers to show them what is involved in stepping up to partial mash. It is not meant to be a tutorial but just an overview of what is involved in brewing a good beer. Many things are the same as in extract brewing, but a percentage of the fermentables in the wort are extracted from malted grain and the rest is added with malt extract. It as a hybrid of all grain brewing and extract brewing. Benefits include still being able to do a partial boil while using grains not available to the extract brewer. Another thing some people claim is that going to partial mash removes that homebrew "twang" that some people taste in their extract brews. Additionally more color control is possible.
We'll skip all of the sanitation steps as you should already know how to do that. First we'll look at the extra equipment needed.
The equipment required beyond extract brews includes:
- mash/lauter tun
- Another pot for hot water.
The fermentables will come from both extract and mashed grain. This grain, like in All Grain brewing, must be milled so that the kernel is broken up but leaving the husk as intact as possible. This can by done by you with a mill, or the place where you bought it can mill if for you. You will also need a certain amount of extract to bring the gravity up to that desired for your style of beer you're making. Typically people use DME towards the end of the boil to keep the sugars from carmelizing.
 Basic steps
- Place your crushed grains in your mash/lauter tun
- Add 1.5 quarts [1.41L] of 168F [75C] water per pound of grain [3 L/kg]
- Stir the grain until the temperature is uniform. Add hot/cold water in small quantities to adjust.
- Let the grain sit for 60 minutes.
- Stir it again
- Pour the wort into your boil kettle.
- Close the valve and add about half the mashing quantity of 170F [75C] water.
- Stir the grain and wait 10 minutes.
- Drain into your brew pot again and add another half quantity of water, wait 10 minutes and drain.
- Add the second batch of wort to your boil kettle.
- Bring to boil and add hops. Boil for time the hops call for.
- When 10-15 mins are left in the boil add DME to hit your target gravity.
Now finish off the brew session like any other extract brew. Cool the wort to ~80F, top off with water, aerate, pitch yeast, wait.