The Fresh Loaf

News & Information for Amateur Bakers and Artisan Bread Enthusiasts

Using Combi oven

bboules's picture
bboules

Using Combi oven

Greetings all,

I'm looking at renting a commercial kitchen to do some baking, but I've run into a snag. The kitchen I'm looking at has a Blodgett Combi oven (I didn't have time to find the model number), but I've been reading that it uses a combination of steam and forced air for cooking.  I've been doing some reading and it seems that using one of these ovens to bake may cause some technical challenges when baking bread.  Does any have any experience with this type of oven that you can share? or know of any resources?  As of yet I haven't found what I need on Google.  And while there are some old posts on this forum on the topic, there isn't a whole lot of guidance.  If anyone can help me understand how to best use this to take advantage of the steam while still getting a nice crust I would be appreciative.  Worst case, I could revert to my dutch ovens, but I prefer not to do that.

Thanks,

Chris

nichan's picture
nichan

For one, these ovens are usually beneficial for commercial purposes. They are great for cooking large portions of food that have to cook through faster and retain moisture and flavor without drying out or burning the outer areas - e.g. turkeys, all large meat roasts (also no need for constant bastings), certain types of fruit pies and also custardy and steamed puddings. If you use the Combi method, i.e. steam and convection heat (a combination of both), what happens to your bread is that you will get a crust that may be crusty but chewy since the constant steam steams the outer area, but cooks the bread faster a lot faster, with even browning and bake up higher and lighter. This is great for large bread types, particularly very moist dense bread mixtures and large bread sculptures to achieve an even color outside without burnt spots. However, if you use steam, then hot air, what you get with normal loaves will be a steamed chewy crust that then using a short finishing period to crisp and brown the crust. It does not always work out for achieving the desired browning without over crisping. The spray method is different because it is not a constant moisture being introduced, and the crisping follows right after through the convection heat so you won't get a over chewy bread for even browning and crisp. Depending on sugar content, the high the sugar the less scorching using the Combi. Unless you experiment per recipe, it is not as viable for normal bread baking. that's the technical challenges they are referring to. You will only be able to take advantage of the steam in the examples of the bread types I'd briefly pointed to.

bboules's picture
bboules

Thanks nichan,

I'm going to be baking some 750g sourdough boules and some baguettes.  I'll give your method of following roughly the same timing for the boules as I would in a conventional oven.  I'll start with the combi mode for ~25 minutes and then try and "vent" and finish with the forced air.  Normally I would bake at 450 F, do you have any thoughts on where I would want to be in the Combi oven?  I hear that you normally use a lower temp.

In any case I'm going to dedicate an evening to just doing some testing and see if I can find some satisfactory method.  I'm also going to try the conventional oven that the kitchen has and rig it with steam using a tray with rocks/chains and some water.  It will be interesting to see which method works better.

nichan's picture
nichan

As long as you do not crowd the loaves, allowing enough air flow between. Crust hardness softens on cooling. Unless it is a very special composition bread which requires lighter crust, use cold lower or bottom. At the higher temperature of 450 F and 750g loaves, it really depends on the type of bread, although most breads should be ok with middle placement, normal. So when you combine a heat charged deck with steam injection, the deck gives you a rapid oven spring, and the steam serves a couple of purposes. The way it works is keeping the crust moist which prevents it from prematurely setting and limiting oven spring. Also it by helping to convey heat energy to the bread at a faster rate, (water and steam are much more efficient at conducting energy than air); and lastly, it gives you that thin, crackly crust that would be rock solid if the steam wasn't present.  A baking stone also works, because if you place the bread straight into the oven on a cold sheet tray, it takes time for the air to heat up the sheet tray and the dough sitting on it. For all breads, the ideal is good oven spring without bottom burning nor tops setting before full rise. If loaf is of a very moist dense type, may be preferable to use lower placement (hot bottom), higher temp to start and then lower temps and longer bake time. Moiste breads with outer crust solidifying before it is fully cooked or expanded is more common and expected with the use of conventional ovens.

Conventional oven - The problem with just using hot air, and turning the oven up, is it still takes a while for the air's heat energy to diffuse into the core of your bread. By the time it's done that, the crust on your dough has probably already started to set, limiting your oven spring.
Depending on your bread type, it would help for the conventional oven you are going to use, to have the tray contraption you are trying. Setting shaped bread on baking parchment before baking helps prevent unwanted hardening or burning of bottoms, especially for french baguettes. Also for easy sliding without misshapening when transferring onto a heated oven tray for baking. Most regular breads are good at middle point in conventional ovens. Very wet dense types require low temps and near bottom placements, and even 'cushioing' (setting baking tray onto another inverted tray to prevent bottoms burning or bread on parchment-lined trays. There is never an ideal oven as far as rack placements. They all seem to follow a set standard that is not an ideal for something that requires between 2 set points. Steam is the constant cooking agent using the Combi. Your baguettes could use a lower placement since the temps are higher. After your experiment you may consider if, as I'm wondering now if the initial 25 mins may be 5 mins too long, but watch it and you can just adjust the time. Or the bottoms may become overly crustily-thick, or even burn at 450 degrees. Try using parchment paper as per your experiment results. 

nichan's picture
nichan

Correction : I can't edit the post but the third sentence should read "Unless it is a very special composition bread which requires lighter crust and the use of cold lower or bottom placement. Apologies.

guitarluvdude's picture
guitarluvdude

I have the same make of Combi at my workplace st have had poor results in making bread. The largest issue is the intense amount of wind in the chamber. The “combi” function does not work as well as you would think even at lower temperatures (300) due the intermittent steam; this results in leather crust.  One would have to baby the loaves while baking, i.e. turn on “combi” setting for first 15 min, then turn off and evacuate any remaining steam without altering oven temp. Convection ovens, gas ovens and combi, by nature, aren’t meant for bread or at least the quality that’s discussed on this website. 

bboules's picture
bboules

Thanks for sharing your experience, as I mentioned in my other post I'm going to do some testing and will definitely be comparing against the conventional oven that I have access to.  It's a shame that this may not work out as I'd hoped, but one has to be adaptable to succeed.

Hugos Deli's picture
Hugos Deli

Hi there,

I am in the same situation and have got by with two convection ovens for the past two years in my shop to do sourdough, foccacia and baguettes. The results have been ok and the customers are happy but there is a lack of consistency and in the quality of the crust. To get an ok result I would be moving loaves from the bottom to the top in sequence to get oven spring (heat from below on the bottom shelf) while I found blocking a down draft with a tray the thing that had the biggest impact. For an even crust I would also have to spin the loaves and finish on the top shelf once the bread had set, all the while spraying at intervals to ensure they open up and the to crisp at the end, obviously not an ideal set up.

I'm considering buying a combi now to replace my shambolic setup as space is a serious limiting factor and combis seem to be more practical in this regard. I had assumed that if my ovens had an even heat distribution, steam, and extra power to finish that the results would be pretty good, but I'm slow to commit given the common knowledge that it must be a deck oven. 

Any feedback from your experience would be great.

guitarluvdude's picture
guitarluvdude

I would strongly argue to reconsider getting a Combi vs your current setup. From my experience, a Combi will cause you just as much grief as your current set up. I think this is one of those scenarios that if you want perfect crusty bread, steam injected deck oven is the way to go. I'll also add, I've had commercial experience baking crusty bread in a large pizza oven(Woodstone); didn't go well. I might have left out, in a previous post, my experience baking in a rotator oven works great for enriched loaves i.e sandwich bread and brioche.

cambui_al's picture
cambui_al

I use a small combi-oven for day to day use, which has a Dry-Heat (fan assist), Steam (98C/208F steam only), and combination with 3 levels of steam, which mixes the two so you can have temps above 98C (208F).

for an 850g Sourdough loaf, I generally use the combination function with a temperature of 170C (338F) on the lowest steam setting for 20 minutes, followed by a dry heat setting at 190C (374F) for a further 25 - 30 minutes. This gives a good golden brown colour to the loaf and a thick, crunchy crumb, which is what I am going for. 

I would say give the combi oven a go - start with a mix of steam + heat, and finish with a blast of dry heat at a higher temp to give your colour, and firm up the crumb.