How to make LESS sour sourdough?

Let me start by noting that this is a question that was asked in the past. I read a few threads about it, but I couldn't see a definitive answer to the question.

My current recipe consists of a 100% rye starter. When I bake I feed part of the starter with all purpose flour (11.7% protein) and then I use a flour mix consisting of 67% bread flour (12% protein), about 28% all purpose flour and 5% rye flour. I also add about 20ml olive oil per 450g flour. The final levain weight is about 80g for 450g of total flour (including the levain flour).

The baking process consists of a one hour autolyse including the salt at this stage, then three stretch and folds every half hour, two hours fermentation, pre-shaping and final shaping. The levain build up and the proofing up to the fermentation stage takes place in a controlled temperature of 23º C to 25º C. I keep the dough in a banneton in the fridge overnight. The following morning the bread shows a significant rise in the fridge.

The bread comes out wonderfully risen, soft with decent although smallish holes in the crumb. However, my wife doesn't like the sourness of the resulting bread. Personally, I don't mind the taste, but I'm looking for a way to reduce sourness in order to keep my wife happy and my baking meaningful and sustainable!

I would appreciate any useful information based on the above.

I can't give you much solid advice, since I am always trying to increase the amount of sour, and much of what i have read is contradictory,

Things that will make it less sour

Use more starter ( sounds counter intuitive, but the greater the starter, the faster the rise, the less sour the loaf )

Refresh the starter and do fermentation between 70 to 76 f

https://brodandtaylor.com/make-sourdough-more-sour/

https://truesourdough.com/18-ways-to-make-sourdough-bread-more-or-less-sour/

Hope this helps.

perhaps in the reading, you didn't pick up on .... what makes a dough more sour, when reversed, tends to make it milder:

larger portions of levain, a levain that was made with several small feeds as opposed to large feeds (% of starter to flour) you can easily combine the dough flours with salt
feed the levain in steps letting it rise somewhat before working in more flour, try 1:1:1 ratios)
no retard or when a very short one
washing a firm starter to reduce acid levels (feed, slice, soak in water, remove and use)
use flours with a high ash content as they buffer the sour taste.
make sure the starter has high yeast population, firm starter? Use just before it reaches peak.

other ways:

trick out the bacteria in the starter by introducing lemon juice, pickled water, vinegar into the dough recipe liquids
switch out a teaspoon of soda instead of salt to the dough, caution, dough will immediately react to soda and start rising more
start a new starter, a recipe that includes some sugar tends to be less sour for some reason, can have something to do with switches on RNA, I don't know. But not all wild sourdough starters are sour. Rye starters tend to be more sour than wheat starters. You could try feeding 20g of rye starter wheat and a pinch of sugar and see where it goes after a week of discarding/feeding. Keep it small and thick, dough like.

Splodge of honey in your starter. Works for me. This wont take immediate effect in a starter but may work quickly in a levain.

I've been working on the same thing (reducing sourness) with my starter. This morning I thickened it up and am now working towards trying out a more dough like starter.

I maintain my starter in a cool but not cold dark place. Its liquid enough that after a small feed I can stir it and theres a small bit of pull on the sides. I feed every few days. Every fortnight I drain surface liquid, stir, halve and 'dump'. Then good feed and add a spoon of honey. Seal lid and back in cool place. Use the excess for a cracking bake.

My starter smells adequately strong, clean and fresh with a hint of sourness. I dont it get very active until I split it.

You can offset sour with half fresh yeast to starter but the recommendation is to only do this for quicker doughs.

A. Switch to white flour starter/levain. If you don't want your bread to be white add ~10% of whole wheat at the dough stage, it will be milder than rye.

B. Double levain amount. More flour in starter = shorter bulk fermentation = less sourness.

C. Do not retard.

D. If everything else fails - you can spike the dough with yeast.

Thank you for so many suggestions!

Being a bit pressed for time, I'll try first to increase the quantity of my starter, but I promise that I'm going to read all the suggestions given very carefully and I'll do some experimenting.

I know it's been a while, but can you tell me if you have succeeded to make your starter less sour and sharing your experiments?

Maybe add salt to both the starter and final dough.