Mash rests and timing between steps

[cenosillica]

I’ve always done a pretty straight forward mash rest and never tried step mashing.

My question is when a recipe calls for a specific time to rest, when does that timer start and stop? What about the time in between when raising the temperature from 122 up to 148 then to 158 (hypothetical but typical mash rests - I’m trying to ask this question style-agnostic) are you running the timer during this ‘step up’ part as well?

Just as a background on my mash tun equipment, I use a keggle w/ false bottom and am considering using a pump to circulate the mash while heating up to the next temp. I also have a concern here about the heat melting the tubing connected to the valve at the bottom.

Also, when heating to the next step and you are beginning to approach your target temp, do you throttle back the heat so as not to overshoot the target?

[hubie]

@cenosillica

My question is when a recipe calls for a specific time to rest, when does that timer start and stop? What about the time in between when raising the temperature from 122 up to 148 then to 158 (hypothetical but typical mash rests - I’m trying to ask this question style-agnostic) are you running the timer during this ‘step up’ part as well?

I typically run my timer when I get to the target temperature.  However, in my mind it would depend upon how long it takes you to get from step to step.  When I step mash, I will do it with either infusions, which means it takes no time to get to the next step, or by decoction, which means it takes a long time to get there.  Remember that the enzymes work over a pretty broad range so if it takes you a long time from one step to another, they are actually converting starches along the way.

@cenosillica

Just as a background on my mash tun equipment, I use a keggle w/ false bottom and am considering using a pump to circulate the mash while heating up to the next temp. I also have a concern here about the heat melting the tubing connected to the valve at the bottom.

This would depend upon what kind of tubing you are using.  A figure I have in my head, which very well could be wrong, is something like 150 F for standard vinyl tubing.  You can easily get high temperature tubing such as Northern Brewer Home Brew Supplies

@cenosillica

Also, when heating to the next step and you are beginning to approach your target temp, do you throttle back the heat so as not to overshoot the target?

I don’t run a RIMS or HERMs system, but what you are describing is what is known as proportional control and is generally a simple and good technique to use when controlling something.

[lazydog79]

@hubie

This would depend upon what kind of tubing you are using.  A figure I have in my head, which very well could be wrong, is something like 150 F for standard vinyl tubing.  You can easily get high temperature tubing such as Northern Brewer Home Brew Supplies

Ditto - Vinyl is rated in the 150’s.  I don’t remember the specific number either.  I remember when I first started AG, I used a vinyl line out of my MLT, and it got pretty soft.  I bought this stuff http://www.northernbrewer.com/brewing/3-8-id-thermoplastic-tubing.html.  Thermoplastic is rated to 275.  NB sells it in 3/8" or 1/2" by the foot.  I used this over the Hi-temp clear stuff because that’s only in 3/8’ and I have a 1/2" barb on my MLT.