Is it better to grind or to crush?
When you take a grain or seed and you are interested in extracting out the maximum amount of solubles and volatiles from it without producing too many tannins from over extraction the debate always turns to particle size and particle size consistency. Whether you are talking about coffee grains or malted barley grains the principles and many of the goals are similar.
The goals of grinding or crushing coffee or grains:
- Break open the cell walls to allow hot water access to the water soluble flavor compounds and the aroma and flavor volatiles
- Dramatically increase the surface area to more efficiently and quickly extract those compounds into the water
- Make the resulting particles as evenly sized as possible to ensure even extraction and avoid negative flavors
- Maximize the amount of soluble material that can be extracted in a short period of time
However in making beer and processing barley for mashing there are a few key differences that do not pertain to coffee grinding.
- You need to be careful not to break the barley germ too many times otherwise you get too much gum resins
- You need to leave the majority of the husk intact to act as a filter mechanism for the mash
According to dictionary.com the definition of Crush is : “to force out by pressing or squeezing; extract.”
And the definition for grind is”to perform the operation of reducing to fine particles.”
So crushing a grain first accomplishes the goal of leaving most of the husk intact by forcing out the barley kernel and then by squeezing the kernel through the crush rollers and opening up the starchy inside and turning it into smaller particles. We don’t want fine particles, we want evenly sized small pieces with whole and solid husks to act as a filter aid during the mash.
So after all that beer science what the heck are we talking about?
Well we bought a stainless steel roller mill barley crusher to crush our grains for making our cerveza artesanal. It is different than a grinder in that it has two stainless steel roller mills that turn in towards each other and push the whole barley kernel between them to first remove the husk and then to break the kernel into smaller pieces. It works like a charm! The particle size is incredibly consistent and the husks remain perfectly intact.
The gap is micro adjustable to control the fineness of the crush depending on which type of grain we are using.
It is also motorized so no more hours of hand grinding grain which is awesome now that we are doing 70-150lb grain batches.
We also built a custom made grain cart to grind the grains wherever we want. We found a local carpenteria who does really nice work in El Salvador conacaste wood (one of our favorite woods with really beautiful grain patterns) and we designed a custom grain cart to hold the grain mill, the scale, the bags of grain, the motor and the buckets to hold the crushed grain. it is fully mobile on wheels so we can move it to wherever we need it.The photo below is of the unfinished cart. Still adding the motor, a few more pieces and of course all the other equipment. But we think it looks pretty nice and it seems to function pretty well for our first nano brewery.
Here’s to perfectly even and well extracted sugars for our beer!