We recently bought a rotary moulder and started making shortbread cookies. We have several rollers and some are really forgiving and make great cookies with different recipies but the one we need to use is not forgiving at all and we cannot have 100% of good looking cookies (75% at best). They either have bits of dought missing or have very tiny holes wich makes a bad looking cookie once baked, I don't know if it is what you call blisters. We are probably doing something wrong either with the recipe, the mixing, resting or dough temperature and or baking. I would really appreciate any advices or guidelines to follow so can make perferct cookies.
i think procure new rotary moulder bcz if problems is with recipe then on other moulders problem should have occured as well. 75 % good ratio of cookies is not acceptable as surely you would be wasting atleast 5-7% in bisuit wastage.
you can try your this recipe on other rotary moulders you have available to see the result. if problem is same of blisters then there is problem with the recipe.
Thank you for you answer, we have tried the recipe on other rollers and it works much better. The design on the problematic roller is less forgiving, and we hope not to buy a new one as we like the design. Is there a specific temperature for using a recipe with butter and with margarine in a rotary moulder? or it doesn't really matter?
Both Butter & Margarine temperatures are important when it comes to rotary moulding - the crystal structure has be retained which helps with the quality of the dough piece being produced.
It is a fine balance in having sufficient mixing to create a "Creaming" or emulsion but still retain sufficient crystals to both survive forming & also give a lighter baked texture
I am more than happy to review your recipe / process
If you send your shortbread recipe, I can check it and give some advives.
you can adjust the recipe which can be machinable in your equipment
but your equipment setting is also so important to get best shortbread.
I make Rotary Moulding machine and if you share the recipe and pictures of the problems, then it would be easier to diagnose.
When you mention 75 % as acceptable? what is wrong on the rest and do you see a pattern of rejection or they are random?
One of the best ways to make sure you have good extraction from your rotary moulder with a high fat content product is to make sure the product is reasonable cool (12C) and kibbled (crumbed)before it enters the moulder hopper, then if you still have extraction difficulties a modified moulding roll with a constant warm water supply through the middle of it will give you a very good product extraction onto the extraction web of the moulder.
Hope this helps.
Michael Mason, Biscuit Engineering Consultant.