The Fresh Loaf

News & Information for Amateur Bakers and Artisan Bread Enthusiasts

Help, fan oven problems

rhodriharris's picture

Help, fan oven problems

So i have a major problem just when i thought i had everything right (so annoying and am pulling my hair out over it.)!!!!  I have changed to a fan oven recently as my old oven was rubbish and couldn' hold temperature, anyway the fan oven is my only choice at the moment.  I made a great starter about a month ago and is wickedly sour, doubles real easily and is fed twice a day everyday.  So i add a couple of spoonfulls to about the same amount of bread flour (a good brand that does the job Allisons extra strong between 12% to 13.5%) and add a splash of water which makes a thick batter and leave for 12 hours overnight on the kitchen top which is not too cold or warm.  In the morning the batter has about doubled and bubbly with good gluten structure.  Next i add about the same weight of flour and another splash of water and a teaspoon of salt to form a dough which is tacky but not sticky.  I stretch fold and knead for 20 mins, autolayse and stretch and fold once more for 10 mins before leaving the dough about six hours to rise and double ( sometimes i give a quick knead after three hours to even out the big air bubbles).  Ok finally in the afternoon i form a boule and let it proof on a thick gauge baking iron baking sheet for about two hours finally baking at 450 degrees farenheit with oven of until it drops to 400, usually takes about six mins to get down to 400f and i have to turn the fan oven back on, rest of bake is roughly around 400f and entire bake is 35 mins. Oven spring lasts approx ten mins and definatly over after fifteen mins.

I use to think the rising times and proofing times were way too long but i get good oven spring and the crumb is airy and final boule is easily four times the original dough size from start to finish. 

The problem comes in about the thirteenth to fourtenth min of baking at the end of the oven spring, the loaf has puffed up, grown in size and expanded, filled the slashes i put in it and looks beautiful, then on cue the right side blows out like a massive eruption raising that side up in the air and making the left side dip down, imagine lifting a manhole cover on oneside and thats the path the top of the loaf takes.  Ok they look ugly but make great sandwiches and the crumb is delicious but this simply wont do.

I've tried lowering and raising the temp of baking but nothing makes any difference, tried steaming and placing a baking sheet in front of the fan so as not to cover it but stop it blowing on the bread but still the same problem.  I cannot block the fan completly as it is not safe to do so and won't consider it.  So realising it is always the right side that blows out and up i inspected the oven and, although it may make no difference, saw that the fan spins from left to right (clockwise as i look at it) and was thinking that this could be the reason the right half of the oven is hotter and blowing the right half of the loaf out. 

More evidence to go on is that after 15 mins of baking when the loaf has done its little erupting act i have decided on the last two bakes that i didn't want another deformed loaf and terminated the bake.  Took half baked loaf out of the oven and cut in half so that i had a good cross section from the left, slightyl risen side, to the right, erupted mega risen side.  One thing stood out and that was a ball of dough in the centre of the right side that was still gooey and not turned to bubbly bread crumb as the rest of the loaf had.  At 15 mins the crust had started to form and was crunchy to cut through.

My shaping is good, seams are sealed and the skin is tight, add a bit of steam at start as well but its a fan oven so dont bother steaming that much, prefer to just wet the dough before slashing. I thought that i might be underproofing but ive tried proofing till the loaf fall flat and still they erupt. 

Anyone who can help would be greatly apreciated, especially Minioven and chuck as you have the answer to a lot of technical questions people have asked and have given me invaluable information before.  I make bread almost everyday and have a lot of experience but this is really making it not fun.  I don't weigh anything as i like to do it by eye and kind of think i have a good feel for it.  Is this a common fan oven problem or am i serioulsy going backwards, PLEASE HELP!

Mini Oven's picture
Mini Oven

A couple of Q's 

What was the crust color all around the loaf, in particular the bottom? 

When the loaf is proofing, how do you keep the surface moist?

How envolved is your boule forming?

Have you tried covering your loaf completely for the first 15-20 minutes?  You could leave the fan blowing if covered.

I'm busy traveling for the next two days so anyone seeing the solution please, by all means, jump in!

mcs's picture

You don't have to convince me that it's the fan, because you are correct.  I have 3 convection ovens and bake all of my bread in them.  As you suspect, the windward side of the bread (the right side) gets hottest, ovensprings first, and gets dried out first.  If you were to bake baguettes in your oven, you'd get a visual of the heat flow in your oven as you see the scoring open up on the right side and travel towards the left, possibly drying out before the left-most scoring springs at all.

I don't know where your bread is being baked in your oven (bottom, middle, top shelf), but you might want to try some experiments before you toss your oven out the window.

1.  Give your bread a 180 degree spin 5 minutes into the bake cycle.  Be careful of steam since it will come blasting out at you this early into the bake.

2.  Try a higher or lower position in the oven.  The air not only moves from right to left, but also in a circular pattern from top to bottom, so you might get different results that way.

3.  If it's possible, you could also do as MiniO suggests and completely cover your bread (with an aluminum or stainless steel bowl) for the first half of the baking so it doesn't encounter any winds at all until the ovenspring is done.  This is known on TFL as 'Susan's Magic Bowl method'.

4.  Just noticed your comment on steaming.  Even though it seems like it's futile to steam in a convection oven, it's not.  Wetting the dough before it's loaded will only keep the surface moist for about 30 seconds.  It's very important to have enough moisture in the air for the first 5 minutes of baking.   I accomplish this by putting about a cup of water on a preheated cast iron griddle when I load the bread.  It dissipates in about 5 minutes at which time the steam from the loaf is starting to escape.


davidg618's picture

You didn't describe the modes your oven has available, so this option may not be available with your oven.

Nonetheless, since I've had similar difficults with the convection fan in my oven, here is my solution.

I preheat with the oven in "Convection" mode. I reason this gives me the most evenly heated oven. I pre-steam (pan and wet towel method) for 5 to 8 minutes before loading the loaves. I switch from "Convection" to "Bake" mode (conventional, the fan doesn't run), lower the oven temperature to baking temp., and immediately load the loaves.

After 10 or 15 minutes with steam (time depends on the loaf shape and size) I remove the steam pan, uncover the oven vent, rotate my loaves 180° and return the oven to "Convection" mode to finish the bake. This has solved all my uneven oven spring problems.

David G



pjaj's picture

I too have a fan oven by Neff, the fan is in the middle at the back, rather than at the side, which seems to be the case in the ovens described above. It has a specific bread baking setting (200 - 220 degrees C) and this uses the fan. Now I don't usually bake boules, rather I bake in pans, 4 at a time on two shelves, two up two down, but I've found that despite the fan, baking is uneven. The ends of the loaves nearest the fan brown much quicker than those near the front. Consequently I turn the pans through 180 about half way through (after 20 min or so) and may swap shelves as well.

This is adequate for my loaves to get an even bake, so I haven't tried using a setting with no fan, but next time, after reading this, I may do so.

You have to be careful about opening the oven too soon to adjust the loaves, I've done it and they've sunk just like cakes can, losing all their oven spring.

One thing might help, have you considered that your total rise "final boule is easily four times the original dough size from start to finish" might be a bit ambitious? There could be just too much gas in the dough for it to hold together during the spring stage. My breads are yeast rather than leven and as I said, baked in pans, but I rarely go for more than 2-3 times. The only time I tried to get more rise by splitting two "normal" loaves worth of dough over three pans, they too sprung and then collapsed.

rhodriharris's picture

Thanks for the info, after investigating the fan and your input i can see now that i do have that problem with the fan blowing the hot air from left to right and the right side experiencing too much oven spring, didn't occur to me that it also blew from top to bottom but since my oven is so small i can't raise the shelf by much more than three inches but will give it a try to see if there any noticable difference.  Yer Mini and the others are spot on with the magic bowl or covering the boule for the first 15 - 20 mins, i have my heart set on a le-creuset dutch oven but here in Wales they cost so much, £140 for 28 cm although they got a great colour selection i can't afford one yet.  I wonder if a glass cheap pyrex type one would do he same or similar as a cast iron le-creuset??

Anyway recently i've just been taking for granted that my starter had doubled before portioning some of for making some fresh sourdough bread.  Could this be causing my slow rising and recently getting hard to rise to double, say the starter hadn't fully risen to double or more and hence when i was taking a small amount i was actually taking an even smaller amount that was not able to cause my dough to rise, if you can understand what i mean?  I just made some batter from the starter to rise for making dough and this time i waited till the starter had almost started to fall before using it and my batter has risen a lot quicker than before??

Maybe my problem lies with my basic sourdough preperation and my dreaded fan oven.  Sometimes i have not added water or if i did very small amounts to my batter made from my starter simply thickening it with flour to make a dough.  Is it ok to do this or does the yeast and lactobacillis waste products just not get dilluted and hence killing them??

Finally Mini the colour of my crust is always a deep caramilised colour completly covered in tiny air bubbles just like the photos of perfect sourdoug, its the only thing my bread has going for it.  By the way the crust tastes like grilled cheese a bit and i'm loving the taste.

Anyone got any input on this??  I will post again tomorrow after my next boule i bake and see if iv'e managed to iron out any problems, i will steam a lot also this also. Thanks.

pjaj's picture
pjaj do a whole range of cheap Farringdon stainless steel mixing bowls, from 1/2 ltr up to 10ltr. I've got the 10 ltr one which only cost £12.25 it's 36cm (14") diameter and 15cm (6") deep. If this is too large for your oven then maybe one of it's smaller brethren would do. They appear to be widely available elsewhere as well.

However, I've never put it in a hot oven, so I don't know if it would distort like some cheap baking trays do, and it's very thin stainless steel - perfectly adequate for its intended use. If the purpose of covering your boule is to protect it from the direct heat of the fan then it should suffice, but if you are looking for thermal mass, then look elsewhere.

I agree that Le Creuset is very expensive. Have you considered looking at one of their outlet stores where you can buy seconds at nearly half price at times?

rhodriharris's picture

Well i just finished baking my next boule, managed to find the switch which turns the oven off completly (it was hiding in a cupboard next to the oven on the back wall).  I preheated to about 515 degrees farenheit, loaded the bread, threw in some water and closed the oven door quick before turning the whole oven off at the wall.  Took about eight mins to cool down to 200 degrees centigrade/400 degrees farenheit which is the point i turned the oven back on and finished the bake at 200 degrees centigrade, i also turned the bread 180 degrees as well.  Suprise, suprise no crazy oven spring on the right side and nice even crumb inside which was a lot less moist that previous boules.  Maybe i've solved two problems in one go, the crazy oven spring on the right hand side of the loaf causing it to look very ugly and the final crumb moisture seems to be a lot more dry and the overall loaf weight is not akin to a house brick!!! wayhey!!!


So i'm in the process of replicating the results as once could be a fluke but twice is deffinatly a result.  I have a couple of questions though-

1) It seems like the higher the start temperature the less the total moisture in the loaf.  I start the baking at around 450 degrees farenheit for 15 mins and i end up with a heavy loaf but start the baking at 515 farenheit and my loaf feels so light even though the last 15 mins of the bake is the same temperature 200 c/ 400 f regardless of the start temperature??

2) Why recently does my loaf just spread rather than rise a lot of times, is this due to to me increasing the hydration of the dough as i get better at handling wetter doughs??

rhodriharris's picture

Well i just baked a loaf and still lifting but not so bad this time, i'm sure i,m underprooving them somewhere and with the fan oven things are accelerating somewhat.  I'm considering some new approaches to combat underprooving and i've started a loaf of with out doing a pate frement so to say rather making the dough from the starter, which i have lots of, and putting it straight into its first rise before a proof and bake.  Also rising and prooving the dough in a much warmer environment to speed the whole process up significantly.

What is the purpose of turning the dough every 30 mins? 

I think i agree with your idea of a baking stone under the baking tray, would this facilitate upward rise and better cooking of the bottom part of the loaf before the crust sets on the top?