Post
by Jocky » Thu Apr 30, 2020 12:32 pm
How cold was your steep getting? You're not really getting much in the way of alpha acid isomerisation at that temperature anyway, so if flavour/aroma is your goal then even dropping down below 60c isn't a problem for extraction (in fact Dr Peter Darby of the British Hop association said to a group of us on a tour of the national hop collection that to preserve the volatiles you should steep nearer to 60c).
Back on the controllers...
If you're controlling a 1kW+ element with a controller that monitors temperature (e.g. PID, EZBoil, STC1000, DSPR2) you're going to need an SSR on the output. These as well as plug and play controllers like the Inkbird may have a relay built in, but they're only safe to switch a few amps at best.
On the other hand an SSvR and a POT won't monitor the temperature for you, they just let you manually set how much power you want to apply. It's a cheap way to regulate power (e.g. to reduce a boil from rolling to a gentle simmer) but won't hold you at a set temperature automatically.
If you want a temperature controller then there are a few options:
A basic temperature controller like an STC-1000 just turns power on and off around a set point. Drop below the set point by a preset amount and you get 100% power until it comes back to the set point. It's cheap and good for HLT or fermentation control, but you end up getting under/overshoots.
A PID is a much more advanced controller that is designed to get you to and keep you at a set point without over or undershoot. It runs an algorithm to determine how much power to apply at any given point, and then turns the power on and off over a period of time, which is usually as low as 2 seconds (e.g. when it needs 75% power it turns the element on for 1.5 seconds then off for 0.5 seconds).
While they sound brilliant, the complexity can cause its own problems as they need tuning for a system and volume.
Not a major issue, but not ideal for an HLT that you're draining during the brew day - you start the day needing to heat 50 litres, but by the time you get to 25 or 10 litres it'll still be firing the element to keep it at temperature as if you still had 50 litres in the tank. Some will also have a manual mode which allows you to select the % of time you want to have the element on.
I have a PID which I got with an eye to setting up RIMS or HERMS, but currently I've turned off all the PID control and use it to control my HLT in the basic on/off mode. I do this as it has a programmable timer so I can set up the night before a brew day.
The EZBoil (DSPR120/320) is brewing specific. It's not a PID, but implements many of the features of a PID in a brewing specific way (whereas a PID is designed to manage anything from a paint spray drying booth to an industrial furnace), so should be simpler. It also appears to use burst fire control, whereby it switches the power on/off many times per second.
Ingredients: Water, Barley, Hops, Yeast, Seaweed, Blood, Sweat, The swim bladder of a sturgeon, My enemies tears, Scenes of mild peril, An otter's handbag and Riboflavin.
