Consider adding flaked oats (dry oatmeal flakes) at a rate of 10 grams / 100 grams of Dry Malt Extract (DME) to the water you then boil to prepare in making a yeast starter. The wet oats can be strained off (sanitised strainer!) after cooling during transfer to the vessel where the yeast will be added.

tizoc has provided a link http://scottjanish.com/case-brewing-oats/ with background

I got the 10% figure from the Scott Janis srticle’s paragraph about viscosity and mouthfeel. There it says that by adding unmalted oats 10% by weight, one gets -19 times more beta glucans and I figure that is good enough if it also works with flaked oats. Is a different amount of oats better? Do flaked oats make as positive a contribution as unmalted oats? I don’t know. My fall-back phrase is, “You’re gonna have to do the experiment.” Lots of experiments.
Note also that huge amounts of goodies for the yeast cells in a starter are provided when replacing up to 40% of the weight with unmalted oats. I am not inclined to go that far, yet.

Thanks for the James Bond starter link. I think the writer is correct. 1) using “supernatant” correctly in a sentence adds credibility 2) use of alcohol(s) to wipe down pouring edges is what is done in lab and discussions of EtOH and MeOH and isopropanol are correct 3) if one grows a big starter long past high Krausen and lets it settle, sometimes you can see two layers of sediment - lighter on top. The better product is the upper layer, so why go to the point where there are two different solids? I will now consider my starter optimal at high Krausen. 4) I have used a homemade stir plate and I agree that significant aeration would occur only at high shear rates and that is bad for yeast cells.

Keep up the good posts, tizoc.

Bob

tizoc - I had not yet tried the combination of starter with oats and shaking. until today.
I just got starting materials for my next batch and will get back to you on that in about a week or so. One week later: The outdoor temperature today was above freezing and I got to brew.
Starter without oats v. starter with oat flakes - to compare Krausen levels
100 gms of golden light DME in 1L of RO water was boiled in saucepan 1 for 5 min, then half (500 ml) was transferred to a second saucepan 2. To saucepan 2 was added 5 gms of flaked oats (not quick oats) and contents of both saucepans were boiled for an additional 3 min. Both were allowed to cool to room temperature (19 ºC) before transfer to sanitized plastic soda bottles of 2 L capacity. Saucepan 2 was poured through a sanitized strainer to remove soggy oat flakes. Both plastic bottles were shaken by hand for 45 seconds. The amount of foam in #2 (oats) was slightly less than foam in #1. Then 5.5 gms of US05 dry yeast was added to each plastic bottle and shaken for 5 seconds. After 4 hours, the foam/Krausen in bottle #1 was greater than in bottle #2 (oats). The liquid in bottle #2 was darker than the liquid in #1. After another 4 hours, the volume of Krausen in #1 was about double of that in #2.
Both have since been pitched to the same batch of wort. The difference will no longer be tracked.
One experiment on US05 in 'shaken, not stirred' starter with oat flakes showed less Krausen than without oat flakes - agreeing with your observation.
Does it mean anything?
Next experiments would be to split the batch of wort and separately pitch the two starters. That was not for today, sorry.