AIO - Mash temperature deviation

[WalletHocker]

Looking at AIO systems and trying to get a handle on if this is really an issue to contend with or not.

What are some of the temperature deviations between the set temperature and the actual mash grain bed temperature that those with AIO systems have experienced?

How do you deal with this deviation?

How long does it take the unit to bring the actual mash grain bed to the set temp (or does it ever even reach the set temp)?

Please list the unit name, measured temperature deviation, correction time and your solution to the perceived "problem".

i.e. Simple Masher, 6F, 30minutes, recirculate and wait

 

[Sammy86]

What are some of the temperature deviations between the set temperature and the actual mash grain bed temperature that those with AIO systems have experienced?

Brewzilla 65L 0° (i had to calibrate the Brewzilla down 1° F) Mine is spot on since the calibration and with the recirculation I don't worry about it.

Im a mash mixer, so I mix mine every 30 minutes let it rest and then recirculate again.

 

[mabrungard]

The temperature of the mash bed is not what needs to be monitored. The temperature of the wort coming out of the heater is what matters. The mash bed will eventually be at the wort temperature.

 

[ScrewyBrewer]

The 62 liter High Gravity system has the temperature probe located in the lid and monitors the wort before entering the mash tun. The idea is to recirculate enough wort volume to overcome heat lost in the tun.

 

[WalletHocker]

Ok, so this is starting to make sense.

1.) If the set temperature is higher than the mash temperature - as long as the wort is recirculating and the flow through the grain bed is good - the two temperatures should eventually meet.
2.) If there is no wort recirculation then it's similar to a stove top method and there are no guarantees but stirring the mash, raising and lower the basket to mix the water/wort outside of the basket does help.
3.) Not sure if these systems are calibrated with water or an actual mash but if the set temperature in one of those mediums doesn't match a calibrated thermometer that's when the calibration offset would be set in the AIO units' software.

The question then becomes how long does it take for the grain bed to get to the set/step temperature with each system?
What affect do these longer equalization times have on the wort and the final beer?
What is the fluctuation (+/-) in temperature when a set/step temperature has been reached?

 

[WalletHocker]

So because the relavent enzymes operate in a range of temperatures and denature from low temperature to high temperature and the AIO temperature is always rising the length of time from one set temperature to another and the grain bed temperature stabilization times have substantial leeway.

The effects on the wort profile though must vary from intended as the time required for stepping and grain bed temperature stabilization increases.

So consistent wort production from batch to batch then depends on learning the heat and lag times of the particular AIO system which is perhaps lessened if only one mash temperature is used.

 

[DarrellQ]

The temperature of the mash bed is not what needs to be monitored. The temperature of the wort coming out of the heater is what matters. The mash bed will eventually be at the wort temperature.

With regards to the Anvil Foundry, I'm not exactly sure that makes sense when you consider that the wort that is recirculated to the top of the grain bed is coming from the dip tube that sits under the malt pipe at the very edge of the burner and the temperature sensor sits outside the malt pipe in the liquid that surrounds the malt pipe. As I've previously posted in other places, I have found that the wort at the top of the grain bed, the wort on top of the grain bed after deep stirs every 10 minutes, always measures 6 degrees less than than what the Foundry displays. How could this not be relevant?

 

[WalletHocker]

With regards to the Anvil Foundry, I'm not exactly sure that makes sense when you consider that the wort that is recirculated to the top of the grain bed is coming from the dip tube that sits under the malt pipe at the very edge of the burner and the temperature sensor sits outside the malt pipe in the liquid that surrounds the malt pipe. As I've previously posted in other places, I have found that the wort at the top of the grain bed, the wort on top of the grain bed after deep stirs every 10 minutes, always measures 6 degrees less than than what the Foundry displays. How could this not be relevant?

That's absolutely what I'm referring too and looking for more examples of the same. These systems seem to have a certain lag and temperature loss in their recirculation circuit with questionably placed temperature probes - so do their grain beds ever hit the set temperature or if they do how long does it take? It would certainly be interesting if more people would measure these differences and report their findings.

 

[DarrellQ]

That's absolutely what I'm referring too and looking for more examples of the same. These systems seem to have a certain lag and temperature loss in their recirculation circuit with questionably placed temperature probes - so do their grain beds ever hit the set temperature or if they do how long does it take? It would certainly be interesting if more people would measure these differences and report their findings.

Indeed! The Anvil folks and their proxies seem to be ignoring the issue. That said, don't get me wrong, I do like the Foundry and would buy another if I had it to do all over again since I seemed to have found a work-around by adjusting the set temp 6 degrees higher and lifting the malt pipe completely out several times during the mash, and doing deep stirs.

 

[mabrungard]

As I've previously posted in other places, I have found that the wort at the top of the grain bed, the wort on top of the grain bed after deep stirs every 10 minutes, always measures 6 degrees less than than what the Foundry displays. How could this not be relevant?

Because the enzymes reside in the wort, not the mash bed. Sure there might be some heat loss as the wort travels through the bed, but the time to denature the enzymes and enzymatic activity is based on the maximum temperature those enzymes experience. If you overheat the wort and denature the enzymes, you will end up with beer that ends up underattenuated and worty flavor. Ask me how I know that!

The other consideration is that the temperature measurement accuracy of your brewing equipment might not be as good as you hope. I recommend operating the equipment with no grain and directly measure the discharge temperature from the unit using a certified accurate thermometer unit. Just because a piece of equipment has an electronic readout, doesn't guarantee that its accurate.

The other thing that I'm curious about is how the grain basket is configured on your machine? Does the basket have have solid side walls and only a perforated bottom, or is the basket perforated on the sides and bottom? If the sides are perforated, then there is a huge short-circuiting going on and that hot wort is never flowing through the majority of the mash bed. Solid side walls are the only way to achieve appropriate and desirable wort flow through the bed.

 

[RufusBrewer]

The best place to measure the affect of your heating element has on your wort is as close to the element as you can. This is true regardless if what you do with the wort.

Brewers are most concerned with accurate temperature during the mash. The temp reaches, sustains and does not exceed one hundred and something degrees. Less than the desired max temp is best avoided, but it is better than exceeding.

If you have a pump, you will loose some heat to the pump and the tubing. You can measure the mash and decide if it is too low or too high and adjust the heating element as your best judgement dictates.

As previously emphasized, you need to monitor the max temp the wort has experienced.

 

[DarrellQ]

Because the enzymes reside in the wort, not the mash bed. Sure there might be some heat loss as the wort travels through the bed, but the time to denature the enzymes and enzymatic activity is based on the maximum temperature those enzymes experience. If you overheat the wort and denature the enzymes, you will end up with beer that ends up underattenuated and worty flavor. Ask me how I know that!

The other consideration is that the temperature measurement accuracy of your brewing equipment might not be as good as you hope. I recommend operating the equipment with no grain and directly measure the discharge temperature from the unit using a certified accurate thermometer unit. Just because a piece of equipment has an electronic readout, doesn't guarantee that its accurate.

The other thing that I'm curious about is how the grain basket is configured on your machine? Does the basket have have solid side walls and only a perforated bottom, or is the basket perforated on the sides and bottom? If the sides are perforated, then there is a huge short-circuiting going on and that hot wort is never flowing through the majority of the mash bed. Solid side walls are the only way to achieve appropriate and desirable wort flow through the bed.

I use a Thermapen, which I paid about $100 for, and I have found it to be highly accurate. Prior to mash-in, the Thermapen reading from the strike water in the malt pipe, and the Foundry display temperature are exactly the same. The malt pipe has solid walls except for the bottom several inches near the perforated bottom. I always cover these perforations on the walls with what Anvil calls "a small batch adaptor." When I started doing this for all grain bills, large or small, my efficiency shot up 10-12%. During the mash, the wort in the grain bed, and the wort coming out of the pump while recirculating consistently measures 6 degrees lower than that which is displayed on the unit. Thus my adaptations of adjusting system temperature 6 degrees higher than desired mash temp, doing deep stirs, and lifting the basket completely out several times during a 1 hour mash so the liquid surrounding the malt pipe mixes in. Thanks for your comments!