by Teddysad » Wed Dec 09, 2020 10:21 am
Just readdressing this with a system I have evolved. I don’t use the centre tube in the malt pipe, and have closed off the hole in the bottom screen. I do the corn/ maize seperate to the cereals. First run is corn not too finely ground. Heat water only up to 91c. Add the HTL enzyme and adjust pH to around 6.0. Add the corn to the water, stirring and let the temp cool to 88c. Cook for 90 mins, stirring well every 10 to 15 mins. By then temp has dropped a little. Add the GL enzyme and a little citric acid to drop pH to around 5.2. Power off and let it sit for 30 mins stirring frequently.
I then lift the malt pipe and let it drain.
Take off the liquid. Then close the tap and sparge with hot tap water to rinse remaining sugars. Discard the corn, top up the boiler with fresh water leaving the sparged water in for the next batch, and repeat the process. That gives me 2 lots of corn “juice”.
After the second sparge top up again and heat to 70c . This is for the cereals - barley wheat rye. In the combinations to suit the mash bill. Again pH adjusted to 6.0. The cereals I cook at 66c for 1 hour, before adding Sebflo Ttl in place of the GL and again adjusting to 5.2 pH. After 30 mins I lift the malt pipe and allow it to drain. This time I catch the sparge water in the drained stuff. Discard the cereal grains.
I now have 3 lots of juice to combine and ferment. My iodine tests show I get a good conversion.
I don’t claim this to be the only way but I have found this works for me to hot mash an all grain bourbon / American whiskey style in the Robobrew
The liquid enzymes avoid the heavy porridge effect and makes stirring, important to avoid clumping, scorching and overheating. I keep the pump running while stirring.