All Grain Brewing :Part 2

Picking up where we left off. We will also go into Sparging or Vorlauf. (It means "To run off" in German) Fly Sparging VS Batch Sparging and No Batch Sparging in greater detail. Now we know about kettles, As before the bigger the better.

Fly Sparging

The usual way most brewers sparge is continuous (also called on the fly, or fly) sparging. In this method, after vorlauf, the wort runoff is begun and water is added to the mash tun at the same rate as the runoff. It's important to go slow so as to extract the maximum amount of sugar and not compact the grainbed, which would stop the runoff. Lauter design is also highly important in fly sparging. Your lautering system must allow no channeling, or the sparge liquor will "drill" straight down through the grain bed in only one or 2 locations and leave the rest of the mash unrinsed. Because the buffering power of the grains in the mashtun is continually being diluted by the sparge water, it's necessary to monitor the pH of the runoff. Too high a pH will cause the extraction of tannins and polyphenols, compromising the quality of the beer. To counteract this, it is often necessary to acidify the sparge water to keep the pH of the runoff below 6. Because the runoff may take an hour or more, many brewers do a mashout step in an attempt to denature the enzymes and prevent further conversion from taking place while the sparge is happening. However, this method will usually yield the highest extraction from the grain.

No Sparge Brewing

A no sparge brew has the entire volume of "sparge" water added to the mash and stirred in before any runoff has taken place. Even though additional water has been added, since it's been added to the mash before runoff has begun, we can more properly think of it as a mash infusion, rather than a sparge addition...hence the name "no-sparge". This method is the easiest way to mash, but at the expense of poor extraction, typically 50%. The advantage, though, is that because all the sugar from the mash is in solution from the agitation of adding the water, lauter design has minimal effect.

Batch Sparging

Batch sparging is like partigyle brewing or the English, but instead of a separate beer being made from each runoff, the runoffs are combined into a single batch. In batch sparging, mashing is done at the normal ratio of anywhere from 1 to 1.3 qt./lb. English Bitter should always be made at a 1:1 Ratio. 

After conversion, the sweet wort is recirculated as normal and the mashtun is completely drained as quickly as possible, and an addition of sparge water is added. This is stirred into the mash, allowed to rest for a few minutes, thoroughly stirred again, and after recircul;ation is once more drained as quickly as the system will allow. Sometimes, multiple batches are added if necessary or an additional infusion is made before the first runoff is begun.

The advantages of batch sparging are no (or reduced) worries about pH because you're not continually diluting the buffering power of the grains, inefficient lautering systems don't really affect the extraction rate since the sugars from the grain are in solution, a mashout is seldom necessary (though may still be desirable) since the wort will be in the kettle more quickly and enzymes denatured by boiling, and extraction rates that range from slightly less to slightly more than fly sparging. The more inefficient your lautering system is for fly sparging, the bigger the gain in extraction you'll see from batch sparging.

More on this in the next part.