Introduction to All-Grain
brewing:
The malt extract brewer re-hydrates malt extract with water to create sweet wort. The all- grain brewer creates wort directly from malted barley grains. This is done by milling the malted grain, placing it with a measured amount of hot water, and allowing the enzymes that are naturally in the malted grains to convert the starches to sugar. The sugars are then rinsed from the grain with hot water.
Why All-Grain brew?
Taking the step from malt extract brewing to all-grain brewing is about achieving greater control of the brewing process while having the potential to increase the quality of the beer.
Why does all-grain brewing allow greater control?
The malt extract manufacturer controls what malted barley is used, what water is used during that process, how the enzymes convert the starches to sugars and how the sugars are rinsed out. As an all-grain brewer you have the option to choose the malt, or combination of malts, that you would like to use. You control the water quality, salt additions and pH levels that are used. By varying the temperature and pH during the period of starch to sugar conversion you control the enzymes that are active and how they work. During the rinsing of the sugar you control the time and pH.
How is quality increased?
Nothing is fresher than taking malted grains and making beer from it within six hours.
The process of utilizing enzymes to convert starches to sugars is called Mashing. The vessel that this is done in is called the Mashtun. The process of rinsing sugars out of the mash using hot water is called Sparging. The hot water is actually called hot liquor once it has been adjusted with water modifiers or acids to differentiate it in the brewery from plain hot water. Therefore it makes sense that the vessel that holds the hot liquor for sparging is called the Hot Liquor Tank.
Some other terms:
Grain – a generic term that encompasses many forms of Barley.
Malt – Barley that has been brought through a malting process. (see addendum)
Malt Extract – liquid or dry form of sweet wort that has been condensed.
Doughing in – Mixing the grains into the mash water.
Grain Bill – the malt portion of your recipe in all-grain brewing.
Remember the basics before getting lost in the specifics:
Mashing – converting starches to sugar at a given temperature
Sparging – rinsing those sugars out using hot water
It really is that simple.
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The Processes of a single infusion mash and related equipment:
Step Mashing is the idea of bringing the mash through different temperature levels, often called steps or rests. Lets take a brief look at some of the steps that have typically been utilized.
Acid Rest: 95-104º F: Starting your mash at this introductory temperature has several advantages, although oddly enough lowering of the pH is not necessarily one of them. George Fix has done research that has shown that mash pH is not greatly affected. This temperature range is optimal for beta-glucanase to break down beta glucans. This leads to an improvement in mash efficiency and later on in beer filterability. You can cannot filter out a sub-micron chemical haze. You can help to reduce it with this rest.
Protein Rest: 113-131º F. During this range proteolytic enzymes break down medium and high molecular weight proteins into smaller units. De Clerk originally wrote that the range of 113-122º F would favor the break down of medium molecular weight proteins while the higher range of 122-131º would favor the break down of higher molecular weight proteins. This has not been found to be true as both occur at both temperatures. You may want to shy away from protein rests unless you can get your hands on under modified malt. Proteins contribute to mouth feel and head retention and a too much break down by proteolytic enzymes may not be desirable. Fix even says that beer with modified malts that have been run through the protein rest have had dull malt flavors. The Kolbach index lists the percent of soluble protein in malt. Those malts with a Kolbach index of over 40 could be considered too modified for protein rests. Those malts with a Kolbach index under 40 might be prime candidates for this rest.
Saccharification Rest (Sugar Rest) 140-162º F. This is temperature at which beta-amylase and alpha-amylase convert starches to sugars. Beta-amylase works best between 140-148º F while alpha-amylase works best between 154-162º F. Unless specific results are desired, a compromise rest in the range of 148-160 has proven to use both enzymes very effectively and with good flavor results.
Mash Out: 165-170º F. After mashing you heat the entire mash to this temperature. Heating up the mash closer to sparging temperature making the sugars more soluble. This increases efficiency. I have read that mash outs are supposed to stop enzymatic action on the mash. I tend not to agree with this, or see why it matters, but I open to any real information or tests that have been done.
Sparging - How to calculate the amount of sparge water needed
Step mashing originated in Germany where undermodified malts were the norm. Decoction mashing, removing a portion of the mash bringing it to a boil and adding it back, was there only real practical way of heating the mash. (see Decoction hand out) By contrast in Britain, where over modified malts are the norm, single infusion mashing has been the historical choice. Home brewers started with single infusion mashing and quickly started to dable in step mashing. Because home brewers are pretty ingenious, and we deal with smaller quantities, other methods of heating a mash have been invented.
1) Decoction (original) – See hand out.
2) Adding boiling water – Super simple but the amount of raise that can be done is very limited and you will be thinning mash while you raise the temperature. You also need a fairly large mashtun.
3) Apply direct heat while stirring – Can be as simple as stirring. Drawbacks are time because you have to be there stirring. Grains can also get below the screen causing scorching. The liquid under the screen may receive too much thermal loading because it is not being mixed enough.
4) RIMS – Recirculation Infusion Mashing System. Drawing sweet wort from the bottom of the mashtun bringing it through an inline heating element and returning it to the top of the mashtun. Advantages are that is a hands off approach. A controller can be used to monitor and maintain temperature. Disadvantages are that you need to bring the wort through a very high temperature rise in a very short period of time. This has cause carmelization in many instances. I will note that many brewers have brewed successfully, making award winning beers on these types of systems.
5) SMART – Step Mash Adjusted Recirculation Temperature. This method is the same concept as RIMS except that you run the wort through a heat exchanger (copper coil) that is place in the Hot Liquor tank. The water in the Hot Liquor tank is kept at 170º F. This means that the temperature rise is more gradual, taking place over a longer period of time. There are no real disadvantages except perhaps that when doing a mashout, it takes a longer period of time as the differential between mash temperature and the hot liquor decreases.