No sparge brewing very simply means that wort produced with this method consists of only the first runnings from the mash. This definition is often misinterpreted. For example, Brew-In-A-Bag (BIAB) is not viewed by the original BIAB brewers as no-sparge brewing for the reasons listed here http://www.biabrewer.info/viewtopic.php?f=89&t=617. The Brutus-20 method uses a “normal” water/grist ratio during the mash, but at mash-out, adds the remainder of the pre-boil volume and recirculates until the mash is homogenous. If a brewer performed a partigyle that used the first runnings independently from any following runnings, the first portion would be a No-Sparge brew.
Benefits of No-Sparge brewing
With No-Sparge brewing, there are simply less steps. For some brewers, this can also mean that a repeat brew of the same recipe can yield more consistent results because the method has less room for variation. Many brewers have found that they can complete 2 brew sessions using the no sparge method in the same time as a fly or batch method session.
2 Vessel and 1 Vessel No-Sparge systems are becoming more and more common. Single vessel breweries include straining baskets and/or bag systems and frequently are accompanied by hoists for handling said strainers and the resident spent grains. No-Sparge breweries are usually smaller than sparging breweries, but are not necessarily simpler.
Because the mash is never rinsed, the natural pH buffer is protected. As far as brew quality goes, this is frequently cited as the most important benefit.
Drawbacks of No-Sparge brewing
Because the mash grains are soaking in the pre-boil mash and are never sparged, they retain pre-boil concentration wort. When brewing a beer with a high gravity this means that there is a relatively large amount of extract remaining in the grains. At the barleywine end of the hydrometer, this is an example of diminishing returns. The higher your pre-boil gravity is, the lower your efficiency to kettle will be. Taken to an improbable extreme, adding a unit of grain would eventually mean losing as much sugar due to absorption as you would gain from extraction. A lesson that can be taken from BIAB brewers is that minimizing dead loss from the MTL and from the BK will have a large positive effect on brewhouse efficiency.
When creating a No-Sparge recipe, a brewer cannot use the same efficiency to calculate recipes of different gravities. Because the varying grain amounts will absorb different amounts of varying concentrations of wort, the brewhouse efficiency will vary in relation to the wort concentration. If a No-Sparge brewer consistently brews beers in the 1.045 to 1.050 range for example, the No-Sparge brewer’s efficiency will appear quite consistant on the same equipment. However, if one brews a No-Sparge 1.030 brew, and a No-Sparge 1.090 brew on the same equipment, the efficiency will be significantly different. If the Mlt deadloss, Conversion eff, water absorption, Bk deadloss, and the boil-off percentage are known, the efficiency for any given post-boil gravity can be calculated. With this information, a recipe can be scaled in regard to the No-Sparge efficiency.
The No-Sparge method has specific advantages for the home brewer, and with the proper know-how, can make great beer. Like any other method, No-Sparge brewing will not be the best method for every style. A Home brewer that produces primarily beers in the 1.090 O.G. range should probably sparge, unless they own a barley farm. Home brewers that are constrained for space, and produce beers from 1.040 to 1.060 OG frequently, can definitely benefit from the No Sparge brewing method.