Callow Cook4All 2018 vertical smoker review

[Wade]

This is a review of the updates Callow have made to their vertical smoker for 2018. This should be read in conjunction with the original Callow smoker review, which can be found here http://www.woodsmokeforum.uk/topic/27-callow-smoker-low-cost-bullet-smoker/. Since its original release the "Callow" smoker has  been re-branded as the "Cook4All". I have referred to the new unit as the Cook4All in this review however towards the end of 2017 the original smoker model was also being marketed under this name.

The release of the Callow vertical smoker at the end of 2016 addressed a gap that existed in the entry level smoker market as it was the first effective bullet smoker with a street price tag of less than £100 (typically £75). When I reviewed it in early 2017 I was impressed by its controllability, especially for the low-and-slow novice, and its versatility for both hot and cold smoking. One area that some users of the Callow did find challenging was in reaching and maintaining the hot roasting BBQ temperatures of 150-180 C. To address this issue Callow have now made some design changes to the unit and released an updated version under the “Cook4All” brand. 

On the Garden Gift Shop they state that:
“This improved model has 4 adjustable vents in the base of the unit and 2 in the lid for improved airflow and temperature control. The charcoal bowl is now fully ventilated for maintaining consistent burning of the charcoal. The temperature gauge in the lid of the smoker has been replaced with a new high-quality gauge for more accurate temperature readings.”

Over the Christmas period I took delivery of one of the new units to see what effect the design changes have had on its operation…

Unit assembly
As with the original Callow smoker the unit was generally well constructed and everything was well packed in the shipping box. One thing that became obvious as I started to assemble it was that the instructions that were included were for the original Callow model. This was not a major hurdle though as most of the construction steps are similar and the steps that were missing were fairly intuitive. Care had to be taken though when installing the new sliding air vents on the side, as it is possible to install them round the wrong way, preventing them from opening. The assembly went smoothly and it took me about 40 minutes. With the unit I had there was a slight problem with the seating of the optional meat/fish hanging rack, but this was quickly rectified by Callow.

Changes to the air management

With the original Callow it was easy to maintain a low-and-slow smoking temperature of 110-120 C (230-250 F), however some users reported that they found it a challenge to reach and maintain the higher hot roasting temperatures of 150-180 C (300-350 F). Although there could be several reasons for this (including the type of fuel being used), a likely contributing factor would have been insufficient air flowing through the coals. This could have been due in part to the charcoal bowl having insufficient ventilation and the positioning air holes in the base of the unit. These factors combined would result in the incoming air being heated as it hit the side of the hot charcoal bowl and some of it passing upwards around the charcoal bowl, and directly through the cooking chamber. Whilst this gave good temperature stability at the lower smoking temperature ranges it could make it more challenging to reach and maintain the higher roasting temperatures.
 

• Charcoal bowl

Additional holes have been made around the sides of the charcoal bowl to allow more air to pass over charcoal. These would seem to be a very sensible addition as the amount of air that comes into contact with the burning coals is very important for managing cooking temperature.

• Bottom air vents

There have now been two main changes to the air vents in the bottom bowl. The number of vents has been increased from 3 to 4 and their position has been lowered so that they are now located underneath the charcoal bowl. This can be clearly seen in the photo where the unit on the left is the original Callow and the unit on the right is the new Cook4All.

• Side vents

Two additional sliding side vents have been added to the body of the unit, located on opposite sides above the top level of the charcoal bowl. It is unclear what purpose is for these vents as when opened it is likely that heat and smoke would vent out through them.

• Top vents

An additional top vent has been added to the lid to allow more exhaust smoke and air to exit. Good air flow through the smoker is important for hot smoking to ensure a consistent fuel burn and when cold smoking to avoid tar deposits being formed on the surface of the food and to assist with moisture loss.

Operational testing

To ensure consistency between tests, the same total amount of fuel was used for each and the tests were carried out with similar external air temperatures (6-7 C – well it is winter in January!) and in a position sheltered from any wind. The total fuel used for each of the tests was 2 Kg of Heat Beads and 200 g of wood pellets. The empty water tray was in position for each of the tests

For the “low-and-slow” tests a Minion was created in the charcoal bowl consisting of 1.5 Kg of unlit coals and 0.5 Kg of fully lit coals in the centre. The 200 g of wood pellets were placed on the unlit coals. The smoke created by these pellets would provide a visual indicator for the air flow through the smoker and highlight any leaks. 

For these tests both the original Callow and the new unit were carried out side by side so that they could be directly compared. In the graph below the Blue temperature line is the original Callow smoker and the Red is the new Cook4All.

For this test all the bottom and top vents were initially fully open. The new side vents on the Cook4All remained closed. The temperature inside both units rose consistently and as they approached 100 C (Arrow 1) the bottom vents were gradually closed to try to achieve a running temperature of 110-120 C. The original Callow responded well, however the temperature in the Cook4All continued to rise. After approximately an hour (Arrow 2) all the bottom vents in the Cook4All were completely closed but the temperature continued to rise until it eventually stabilised at ~150 C. The temperature in both smokers then remained stable for several hours.
To test that it was the air management that was controlling the temperature the bottom vents were then opened fully on both units to see if the temperature would increase (Arrow 3) – which it did.
To see what effect the sliding side vents would have, these were then opened fully (Arrow 4). This resulted in the internal temperature of the Cook4All immediately begin to drop.

The results of these low temperature tests indicate that the original Callow and new unit initially behaved in a similar way. As the rate of temperature increase was the same in both units it indicates that the design changes made to the top and bottom vents had not had much effect. When I tried to stabilise the temperatures though there was an issue with trying to keep the temperature down in the new unit. With the type of round vent used on the unit you are likely to get some air leakage, and the addition of the 4th bottom vent may have resulted in too much air leakage for the required low temperatures to be maintained. This theory was supported in later testing where one of the bottom vents was completely taped closed resulting in the lower temperatures being easily reached and maintained.

For the hot roasting tests the initial setup of the charcoal was adjusted for higher temperature cooking. For these 0.5 Kg of unlit coals were used with 1.5 Kg that were fully lit.

This test was only performed using the new unit. All the bottom and top vents were initially fully open and the new side vents closed.

In this test the hot roasting temperature was quickly achieved and was easily maintained at ~180 C. Using the 2 Kg of fuel an effective cooking time of over 3 hours was maintained. For economy, these tests were each limited to 2 Kg of fuel however as the maximum capacity of the charcoal bowl is between 3-4 Kg, increasing the initial amount of fuel used would significantly increase the effective hot roasting time.

Additional tests were subsequently carried out where the effects of the additional top and side vents were observed. In each case the opening of the side vents resulted in the internal temperature of the unit falling. Opening and closing the additional top vent had no clear reproducible effect on the internal temperature.

Other changes

There have been two additional changes made since the release of the original Callow unit.

• Door fastener

The door in the main body has had the fastener upgraded. This is an improvement and has given the latching of the door a more positive feel.

• The lid thermometer

This has been replaced with an upgraded unit. Testing showed that at 100 C this unit was accurate to within a couple of degrees. As the temperature of the unit increased though its accuracy decreased.

This type of thermometer is commonly used in the lids of BBQs and smokers and they are renowned for being inaccurate  - this is why we recommend the investment in a digital twin probe thermometer for use with any smoker. 

Review conclusions

With a street price tag of around £75 the Cook4All/Callow smoker provides good value for money for those starting out along their smoking/BBQ journey. It also makes a very cost-effective additional unit for the more experienced smoker or for those branching out into cold smoking. Whilst I feel that this new version of the unit has been a little over engineered in places, the lowering of the bottom vents to below the charcoal bowl has had a very positive effect for maintaining the higher hot roasting temperatures.

Whilst the repositioning of the bottom vents has been an improvement, the addition of the extra vent there appears not to be adding any real benefits regarding temperature management and it is likely that it is contributing to unwanted additional air leakage. This 4th vent also adds complexity when it comes to making fine temperature control adjustments while smoking. When using this unit you will probably simply keep one of the bottom vents permanently shut. 

The lower location of these vents places them almost at the bottom of the bottom bowl which does make it harder to see the open/close position without kneeling/laying on the ground or without using a mirror. This is more of an irritation though than a problem. 

The addition of the sliding side vents appears to be unnecessary and you would be best to keep them completely closed when using the smoker.

The acid test I suspect is, would I recommend this updated unit to a friend who is new to smoking? The answer to that is yes. It is still a good value all-round vertical smoker that can be used for hot and cold smoking and also for grilling. It would fit nicely into the Birthday/Christmas present price bracket for many families.

[Wade]

This review was performed on a unit "out of the box" however whilst running the tests it became obvious that a few simple user mods and technique adjustments would improve the already good operation on this smoker. Over the next week or so I will prepare some posts of these and the effects they have on the unit usability.

[Smokin Monkey]

@Wade, great review on the new “Cook4All” The lowering of the bottom vents have had a positive effect on the air control. Using the side slide vents for a cooling effect to reduce the temperature, is not really cost effective, as you introducing cold air, while the coals are burning hotter due to air leakage from the bottom. The result being increased fuel usage. The better option is to blank one of the bottom holes.

[Wade]

This review was performed on a unit "out of the box" however whilst running the tests it became obvious that a few simple user mods and technique adjustments would improve the already good operation on this smoker. Over the next week or so I will prepare some posts of these and the effects they have on the unit usability.

[Steve j]

Great review wade, as with all these budget type smokers there are drawbacks however this one seems to have significantly less and will be easily overcome with small mods. On the plus side the company are doing their best to engineer these out. It's a win win

[valve90210]

Another great review Wade, as an owner of the original Callow I'm quite pleased that it's not a huge improvement over what I have (saves me having to buy one which might man I can save for a ProQ or Weber at some point) but it is good to see that it's still a good smoker and one that's perfect as an entry to the smoking world where people might not want to put quite so much money in to begin with.

[Sarah87]

I now want to buy this smoker gor my husband, but all i find are obes that look like the vents are in the position of the original model.... has there been another release?

[Icefever]

14 hours ago, Sarah87 said:

I now want to buy this smoker gor my husband, but all i find are obes that look like the vents are in the position of the original model.... has there been another release?

Wade is the guy for this one....

Ice.

[Sarah87]

7 minutes ago, Icefever said:

Wade is the guy for this one....

Ice.

Thanks! I looked on the callow group and saw there now seems to be a mark 3, and also looked at the website wade mentions here, took the plunge as could only see one model everywhere. Got a book and a probe thermometer, just gonna grab him some charcoal and wood and his present is ready. Any reccomendations welcome. Thanks!

[Icefever]

Just now, Sarah87 said:

Thanks! I looked on the callow group and saw there now seems to be a mark 3, and also looked at the website wade mentions here, took the plunge as could only see one model everywhere. Got a book and a probe thermometer, just gonna grab him some charcoal and wood and his present is ready. Any reccomendations welcome. Thanks!

For his first cook I always suggest a spachcock chicken.  It's easy  just cook it nice & slow, you have the thermo with is a great bit of kit that we all use.  Just cook to the internal temp,  there's loads of info on here, any questions just shout out and somebody will try to help.

 

Ice.

[Sarah87]

3 minutes ago, Icefever said:

For his first cook I always suggest a spachcock chicken.  It's easy  just cook it nice & slow, you have the thermo with is a great bit of kit that we all use.  Just cook to the internal temp,  there's loads of info on here, any questions just shout out and somebody will try to help.

 

Ice.

Thanks!

[Wade]

I have just spoken with Callow Retail and they tell me that the current model is still the Mark 3 - this is the one that we helped to redesign to give good temperature control. The only difference to the original mark 3 is that they have upgraded the lid clamps, as the original ones were failing in a few cases.

I hope this helps

[Sarah87]

5 minutes ago, Wade said:

I have just spoken with Callow Retail and they tell me that the current model is still the Mark 3 - this is the one that we helped to redesign to give good temperature control. The only difference to the original mark 3 is that they have upgraded the lid clamps, as the original ones were failing in a few cases.

I hope this helps

Amazing! Thanks! He had better like it now!