Mashing is the process that converts the starch in the malt to sugar so the yeast can use the sugar as a food source. When barley is malted a variety of enzymes are created and each one has it's own temperature region that allows it to be active. A step mash holds the grist and a specific temperature for a specified amount of time to allow an enzyme to act. A typical rest schedule is: 122F 5 Min. Protein Rest 144F 30 Min. Beta Amylase Saccrification 156F 30 Min. Alpha Amylase Saccrification 170F 5 Min. Mash Out to Denature the Enzymes It is rare to use all of the steps, and there are a couple more that we don't list here that are even less common. An often used mash schedule is Protein Rest, Beta, Alpha and Mash Out only.
In a recirculation, your grain bed will set up and act as the main filter. The screen is there to support the grain but not act as the final filter. The small gap around the edge of the false bottom and the kettle gets clogged with grain quite quickly. Over the years we have had them made as tight as we can while still allowing easy installation and removal. When customers are manually recirculating their mash, we recommend puttin a fine mesh hop bag on the end of the line to catch any residual grain pieces that are making their way through. If you are looking for crystal clean wort after recirculation, you really want to pump, because a pump moves much more volume through and can pull more of the smaller grain bits through and deposit them on top of the mash faster than you can by hand.
Most people use a pump to recirculate wort during mashing, to pump hot water during sparging, or to move hot wort from the boil through a counter-flow wort chiller.
You want to be mashing anywhere in the range of 146F to 156F. Mashing at lower temperatures yields more readily fermentable short-chain sugars and yields a drier beer. Higher temperature mashes yield beers with higher final gravities and more body. Mashing over 158F tends to yield beers that are overly astringent due to the extraction of harsh tannins from the grain husk at that temperature. If you are in the 152F range, that is a good, all-around temp to reach for.
There are many different theories on water to grain ratio, but pretty commonly excepted is anywhere from .9 to 1.1 quarts of water per 1 pound of grain. With that in mind here is what we found. At 1.1 quarts of water per 1 pound of grain we were able to fit 28 lbs of grain with the ag403 false bottom in place. If using a 1 to 1 ratio you could fit in 30 lbs and at a .9 to 1 ratio you can fit in over 32lbs of grain.
This is a fairly common issue, and one that is easily fixed. Much of it does depend on a few key points : 1 - That the pump is below the spigot level of the vessel you are pumping from, and that the tubing isn't excessively long below the spigot level. As these pumps are designed to push the liquid, it does not pull or self prime. Pump placement is important for these types of non-self-priming pumps. 2 - All the ports and tubing to the inlet of the pump are 1/2" I.D. There may be some situations where a port is only 3/8", but the tubing should not be. 3 - All ball valves in line are fully open when starting the pump. If these three criteria are met and you are having cavitation issues in warm/hot fluids then try this. Either set up a switch inline from your pump to the socket, or quickly unplug your pump and plug it back in again after waiting about 60 seconds. If you have a switch, simply turn it on and then off again instantly. What we are doing is turning the impeller head, so each section of the impellor can allow the liquid inside the pump head to push out any air that might be stuck in there. If you do this 3 times very quickly, you should be able to give it full power after that, and have full flow.