Thank you, Gary, for this detailed and informative review of the article I shared. Fully agree that the article could have more detail on the parameters you mention, and that a discussion of benefits and costs of the process discussed would be helpful. I come at this with no background in grain processing other than some observations over the years and reading largely in the wider context of understanding the diversity of millets and how they might become more common foods in our part of the world. A few questions (numbering not alignd with your points): 1. What are the differences between the hydrothermal process discussed in the article, and parboiling on the one hand, and other forms of treatment of grains for shelf life on the other? My understanding was that the hydrothermal treatment would shorten cooking time, but not yield a minute millet. (In any event, I'd agree that the cooking time of any small millet is not so long that it would seem a barrier to use.) 2. How significant is bitterness in grains of various millets? Under what conditions? 3. Leaving aside the potential for residue of hulls affecting flavor, and a low quality of grains, what are the roles of, for example, phytates, saponins, and the oxidation of natural oils in imarting a bitter flavor in the grains? 4. What are the ways of delaying oxidation of natural oils in millets (and other grains)? I.e., rancidity. (I understand, for example, that such oxidation is a particular problem with pearl millet destined for packaging and distribution to stores, so what you see for sale has been treated;) I would find it helpful to have a schematic of fundamental and optional processes in handling millets from (de)hulling through various types of produts (with a focus on food uses). One example of what I mean can be viewed at https://www.pinterest.com/pin/244179611041758414/ - altho I would want to revise and expand it. Maybe such a comprehensive diagram already exists somewhere? In composing this reply I accessed an article on processing millets for shelf life tjat I shared on Collab in Nov. 2024. The citation and description are the last item at https://lists.millets2023.space/archives/list/collab@lists.millets2023.space... (Note to all: while there, try searching the Collab archives for any item of interest using the search window at the top right of the page). DO, EL, MI, US NAMA On Mon, Jun 8, 2026 at 5:25 PM Gary Wietgrefe via Collab < collab@lists.millets2023.space> wrote:
Hydrothermal process in the Collab article was interesting from the point of eliminating "bitterness" of proso. It implies bitterness comes from residual hulls after dehulling and from oils of the hull. The Milling and Grain article states:
- Polishing: At this stage, any residual hull fragments containing natural oils that can cause bitterness are additionally removed. This significantly improves the taste profile and eliminates unpleasant aftertaste.
Unfortunately, the promotion article does not address the hidden issues of quantity of residual hulls removed, original tannin levels, fiber, ash, and micronutrient changes in hydrothermal processing.
1.) *Hulling* is a slow process with the faster millet seeds pass through huller the more unhulled seed remains intact affecting cooked flavor. Curious, in the hulling stage how many seeds per thousand retained hulls before the hydrothermal process?
2.) *Seedcoat color*: What was the original hull color? Proso hulls vary from black to white with red, brown, gray, silver, yellow, green and miscellaneous shades in historic varieties. Each likely carry different tannin levels which can influence bitterness (e.g. like the difference between white and red sorghum seed). Soaking and processing may also decrease tannin levels.
3.) *Nutrient profile*: What is the optimum processing of millets? Processing affects the nutrient profile. Seedcoat (hull) of millets and other grains carry valuable nutrients. What was the dietary fiber and micronutrient profile of whole and dehulled millets before and after the hydrothermal process?
4.) *Minute millet*? To speed rice cooking, General Foods developed Minute Rice to help working moms speed rice cooking. Is cooking time slowing or preventing the adoption of proso as a food?
I am not surprised that hydrothermal processing proso improves purity, speeds cooking, improves shelf life, and likely reduces ash content, but I want to know what is gained and given up during the process?
Proso is relished for its beneficial nutrient profile. High in dietary fiber, B vitamins (i.e. thiamin, niacin, riboflavin) and nutrients (i.e. iron, potassium, magnesium, phosphorus, manganese). Whereas like hydrothermal millet, Minute Rice maintains protein and carbohydrate levels but supposedly has less (labeled and unlabeled) thiamin and niacin (B vitamins) and less iron and potassium. See Is Minute Rice Different? Uncovering the Truth Behind the Convenience - ShortFoodBlog <https://shortfoodblog.com/is-minute-rice-different/>.
Many of the questions I raised above are addressed in this 2025 proso study of various processing and cooking methods. Change in nutrient profile is important with the potential of increasing bioavailability of nutrients, like iron. See Impact of hydrothermal processing on the mineral, antinutritional, antioxidant and functional characteristics of proso millet (Panicum miliaceum) | Food, Nutrition and Health | Springer Nature Link <https://link.springer.com/article/10.1007/s44403-025-00027-y>....Gary Wietgrefe
On Mon, Jun 8, 2026 at 8:50 AM Don Osborn via Collab < collab@lists.millets2023.space> wrote:
"Innovations in Hulled Millet Processing, Impact of Hydrothermal Treatment" (24 Mar. 2026) is a feature article on the India-based Milling and Grain website.
https://millingandgrain.com/innovations-in-hulled-millet-processingimpact-of...
It discusses implementation of a hydrothermal treatment of "millet" by Agrofirma Pole LLC (Ukraine). Based on the latter's location, I'm
assuming
this is proso millet.
"Hydrothermal treatment is an advanced processing technology that uses steam and precisely controlled temperature to treat the grain (hulled millet) before further processing (e.g., milling into flour). This method is applied immediately after the initial cleaning stages – specifically after dehulling (removal of the flower hull), calibration, impurity removal, sorting and metal detection."
I don't know how this method differs from what may already is done to treat various millets for shelf longevity. In any event, the article gives a thorough description of processing that incorporates hydrothermal treatment.
Don Osborn, PhD (East Lansing, MI, US) North American Millets Alliance
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