Cookies won't crisp underneath?

[brooksms]

We’re talking 4.5 oz plain chocolate chip cookies here. I haven't tested anything else yet but have tried multiple chocolate chip cookie recipes to make sure. 

I had four Garland gas commercial convection ovens installed recently. They were purchased lightly used on eBay and sat in storage for almost a year. The day they were installed, the cookies were the perfect shape and color but completely raw in the middle. I tried high and low fan, various temps/times, always used thermometers. Now, after stepping away for a couple weeks, the centers are much better with the same settings. Weird..but good! So far they look the best baked at 300 F regardless of fan speed. 

However, the cookies are not getting crisp underneath. The tops and edges are crispy while the bottom is a soft kinda bready texture. It’s plenty golden. I’m using aluminum sheet pans with thin parchment as I always have. The cookies spread too much or too little when temp is different. The manufacturer is less than helpful. I've made multiple variations of these cookies in a different commercial gas convection oven without any problems. Any idea what might cause this and how to fix it?

[Nyleve Baar]

I never use the convection function for cookies. Bottom heat only. Don't know if you can turn it off on your commercial oven, but that's what I'd do.

[teonzo]

300 F is quite low for cookies, it should be around 330-350 F. Is it the temperature you set on the oven, or did you check the real internal temperature with a thermometer?

Usually the problem you describe is given by insufficient heat coming from below, best thing to do is checking the real temperature with a thermometer, placing it in various sides inside the oven. Insufficient heat from the bottom can be caused by an unbalanced oven, by wrong settings, or by the pan itself (if it's too thick, or if the aluminum bottom surface is too new and shiny).

To get a better idea you should check with a thermometer, then post some photos of the cookies and the bottom of the pans.

 

 

 

Teo

 

[brooksms]

29 minutes ago, Nyleve Baar said:

I never use the convection function for cookies. Bottom heat only. Don't know if you can turn it off on your commercial oven, but that's what I'd do.

 

Unfortunately not an option! Convection allows all racks to be used at once which is necessary for the bakery. The only oven controls are temp and high/low fan. 

[brooksms]

28 minutes ago, teonzo said:

300 F is quite low for cookies, it should be around 330-350 F. Is it the temperature you set on the oven, or did you check the real internal temperature with a thermometer?

Usually the problem you describe is given by insufficient heat coming from below, best thing to do is checking the real temperature with a thermometer, placing it in various sides inside the oven. Insufficient heat from the bottom can be caused by an unbalanced oven, by wrong settings, or by the pan itself (if it's too thick, or if the aluminum bottom surface is too new and shiny).

To get a better idea you should check with a thermometer, then post some photos of the cookies and the bottom of the pans.

 

Teo

 

 

Commercial convection ovens require a lower temp than home ovens so 300 is close to 350 at home non-convection. I do use thermometers to make sure the temp is accurate. All ovens are different of course but the other commercial one I used baked perfectly at 300 using the exact same pan and parchment. So bizarre! It's hard to tell from pictures because they actually look great. You can't see the soft texture underneath but can definitely feel it. I'm researching more now and read that gas ovens tend to be more humid. I wonder if that's the problem!

[teonzo]

I have a bit of experience with professional ovens, never went below 330 F for cookies...

You should be more precise when explaining what you are doing. You just wrote you are filling all racks, which is a very important info you did not write in your first post. How much space is there between 2 pans? Some photos would be of help, one of a pan full of cooked cookies, one of the bottom side of a cookie, another one of a section of a cookie. If you want to be helped you need to give as much infos as you can.

 

 

 

Teo

 

[brooksms]

2 hours ago, teonzo said:

I have a bit of experience with professional ovens, never went below 330 F for cookies...

You should be more precise when explaining what you are doing. You just wrote you are filling all racks, which is a very important info you did not write in your first post. How much space is there between 2 pans? Some photos would be of help, one of a pan full of cooked cookies, one of the bottom side of a cookie, another one of a section of a cookie. If you want to be helped you need to give as much infos as you can.

 

Teo

 

 

Interesting! In these ovens, the cookies do not spread much at that high of a temp. They stay very domed. For these tests I have not been filling all racks, just one. We have tried staggering pans on multiple racks but no change there. I just meant typically the racks will be full when the business is operating. I will take more pictures the next time we test, if I come up with any other options to try. The only settings are high/low fan and temp so there's not a ton of options to adjust.