Once you’ve mastered brewing good beer using extracts and specialty grains, you may want to try your hand at full-grain brewing. This essentially makes you responsible for the entire process of beer making, just like craft and macro-brewers the world over.

In full-grain brewing, you produce fermentable sugars from malted barley (mostly), thus replacing malt extract with your own ‘extract’ that comes from converting starches found in barley to sugars, and eventually, beer.

Understanding the basics of full-grain brewing helps you understand the eventual equipment you’ll be using and the steps to making great tasting beer at home. This post is really a very bare-bones description of the whole enchilada. I don’t want to tie you up in jargon-heavy knots, and this ain’t going to be a chemistry lesson either. Just solid advice (I hope).

Also, here at the Beginner Brewer, we really, really like the Brew-in-a-Bag (BIAB) method of full-grain brewing, so I’ll also be focussing mostly on BIAB-relevant stuff.

Converting grain into sugar: Mashing

Full-grain brewers convert the starches found in malts to sugars through a process known as mashing. When you mash grains, you essentially suspend milled (cracked) grains in a watery soup that is held at a specific temperature (usually in the region of 67 degrees Celsius or  153 Fahrenheit), for a specific time (usually 75-90 minutes), and at a specific PH level (usually in the region of 5.3).

Why all these parameters? It’s because of enzymes found naturally in malted barley. Enzymes are the proteins that convert starch into sugar, and they need particular conditions to become active and start doing what they’re good at: helping your grains along the path to becoming beer!

Full-grain brewing gives you more choice in how the beer will turn out (on the downside, it gives you more opportunities to screw things up!). Mashing is where a lot of that takes place. Depending on the mash temperature and time you choose for your grains, you can select the amount of body (residual sweetness) your beer will have. It will also determine how many fermentable sugars you have in your wort. This, in turn, determines the Original Gravity, Final Gravity, and alcohol level of the beer.

The short of it is:

  • Higher mash temperatures result in a sweeter beer with greater body and less alcohol
  • Lower mash temperatures result in a dryer beer with less body and more alcohol
(For the serious beer geeks out there: yes, there are more variables that affect body, ABV, and overall taste of the beer–but these are the basics, so chill out already!)


Mashing Equipment

Brewers generally use a vessel called a mash tun to mash their grains. This can take the form of a simple stock pot lined with a bag (i.e. BIAB), or an insulated vessel fitted with a false bottom (homebrewers sometimes use converted picnic coolers etc).

At the end of the mashing period, the temperature of the mash is raised (to about 77 degrees C; 170 F), which stops the conversion process and extracts additional fermentable sugar from the grain. This is called mashing out, but is not always practiced (or needed).

Getting the most out of your malt: Lautering

While mashing the malt tends to do most of the work in terms of converting starch to sugar, the all-grain brewer must still separate the grains, husks, and grist from the wort, otherwise, you have malt porridge, not beer!

This process is referred to as lautering. Generally, it involves recirculating the wort a few times, in other words, pouring the cloudy wort through the grain bed of the mash/lauter tun (these are often the same vessel for homebrewers) until the wort starts to run clear.

So the grain bed acts as a natural filter for the wort, just like your water filter at home. But, the grains themselves still hold on to a lot of sugars simply because of the porridge-like consistency of the mash. To wash out all the remaining sugars, most, but not all, all-grain brewing methods call for sparging, which is the technical term for washing additional sugars from the grains to increase the amount of fermentable sugars (and flavor compounds) in the wort.

There are different methods of sparging, each with pros and cons, but I won’t get into those now. Suffice it to say that sparging can be important in some, but not all methods of brewing all-grain beer. This process of sparging can take anywhere from 20-90 minutes, depending on the particular method chosen. As an aside, the nifty thing about using BIAB as a method is that you don’t really have to sparge as such. Bonus!

Once the grains have been mashed, and the wort recirculated and sparged, all-grain brewers end up where extract brewers begin: with sweet wort in their brew kettle, ready to be boiled and converted into beer! Hell yeah!

Lautering Equipment

As mentioned, lautering and mashing often happen in the same vessel for homebrewers (and microbrewers).  It is certainly possible to have a separate mash and lauter tun, but then things get slightly more involved. Again, in BIAB, things are far simpler (we like it that way over here), and you use only one vessel for mashing, lautering, and boiling your wort.

Where to from here?

I hope this post has at least somewhat demystified all-grain brewing for you (if it hasn’t, let me know!). As I’ve said before, you can still produce excellent, award-winning beers using extracts, specialty grains and the methods I’ve outlined in previous posts. But if you feel like a bit of a challenge, or you want to experiment with every style of beer and every type of malted grain, then all-grain brewing can help you do that.

In my next post, I’ll discuss what is without doubt the easiest, cheapest way of getting into all-grain brewing: Brew-in-a-Bag. So read that post before mortgaging your house and rushing out to buy that three-tiered, deluxe brewing system, please.