Onions and....
I have been in many a BIR kitchen and in the olden days (early 80's for me) the base sauce was always cooked with whole onions, Oh so many chances to ask so many questions wasted in my drunken youth!.
So why would they take the time and trouble to peel an onion leaving it whole?. It seems cutting through the onion starts a chemical reaction that makes them bitter, so that could be the answer.......But I remember my Nan peeling onions in this way, did she know about this chemical reaction or was it because its the way she was shown how to peel them?. I also use whole onions in my base but by FAR the biggest factor that will effect the sweetness is the age of the onion (OK some would say variety but the kitchens I have been in all use standard brown cooking onions usually British) I remember once ordering a Jalfrezi from one of my usual TA's the manager told "the the chef apologises if the dish is a little sweeter than normal as he is using NEW SEASON ONIONS and will adjust the spice to compliment the flavour" he said when the new season onions come in they mix them with older onions but on the last delivery both lots of onions were new season.
And it was very sweet compared to usual.
New season onions are out late August early September.
If you can buy from a farm shop all the better as you will know how old they are.
26% of the world's onions are grown in China!.
Using fresh new season onions that have not been force dried will result in a very sweet base and the difference's in the finished dish is immediately noticeable.
I hope this helps some of you out on the quest, it may not be the final piece of the jigsaw but I think it can be an important factor in creating "the taste".
