The question of how to improve efficiency often comes up, and I sometimes get PMs asking advice. Rather than repeat the same information, I thought I would write my thoughts down in this thread so that it could be referenced in the future.

Efficiency issues are often difficult to diagnose -- it is just something you have to figure out through trial and error (for this reason, always take detailed notes of your recipe and process each and every brew!). Here are some ideas to think about, in approximate order of importance:

• Your crush will have a big impact on your mash efficiency (although some debate this point). Regardless, the biggest gains in efficiency that users tend to report are when they improve their crush (e.g., buy their own mill). If your LHBS is crushing your grain for you, consider that most shops will set their crush so that their customers get between 60 and 70% efficiency. They may claim it is to help brewers avoid stuck mashes, but conveniently, it also helps them to sell more grain!

• The ratio of sparge water to mash water is a critical factor determining efficiency when batch sparging. Some brewers forget that high gravity recipes will have proportionally less sparge water (because so much water was needed to mash the large volume of grain), and therefore, they will also have less water to dissolve extracted sugars resulting in lower extract efficiency. This seems to be particularly true for those who batch sparge. The two common solutions are either to add extra sparge water and lengthen the boil to compensate, or to simply plan for the reduction in efficiency in the recipe.

• It is very important to hit your mash temperature and hold it for the length of the mash to get full conversion. A common problem is that people miss their temp (e.g., didn’t pre-heat their mash tun or their thermometer is out of calibration), and their extract efficiency suffers because the enzymes in the mash were operating in less-than-optimal conditions.

• Wort losses in the system (e.g., incomplete draining of mash tun or other dead spaces in gear like counter-flow chillers, etc.) can take a big toll on your brewhouse efficiency. These are sometimes overlooked because people are too focused on their extract efficiency rather than their overall (brewhouse) efficiency.

• It is hard to accurately compute efficiency if you don't have precise measurements of your water/wort. Sometimes people think they are getting poor efficiency in their system, but it just turns out they are over-estimating the amount of water used in a brew or under-estimating the amount of wort collected.

• When mixing your grain with water at the beginning of the mash, it is CRITICAL that everything is mixed completely to avoid doughballs or dry lumps of grain. If the grain is not sufficiently wetted, it won't convert, robbing you of efficiency points.

• When batch sparging, the temperature of the mash-out and/or sparge water influence your extract efficiency. You want to make sure that either your mash-out infusion or your first batch sparge addition are hot enough to raise the grist to as close to 170 F as possible. This allows more sugar to be dissolved and reduces viscosity to facilitate easier lautering, both of which will improve your efficiency.

• Also when batch sparging, it is critical that you stir the mash fully after adding mash-out water and/or the first sparge water addition. It may help to stir before each subsequent sparge water addition, but that depends on your system.

• pH of the mash is usually not a problem for most brewers, but some water sources can be problematic. If so, the use of a pH stabilizer, like Five Star 5.2 buffer can help achieve an optimal mash pH, and may result in a 5 - 10% increase in efficiency.