The Weston A. Price Foundation published my article So Much More Than Scottish Porridge: The Rich Culinary History of British Oats in the Winter 2023 edition of their journal Wise Traditions.
It is an exploratory dive into the wonderful legacy of cooking oats that the peoples of Scotland, Wales and Northern England (who survived on this grain) have passed to us and writing it fired me up: I’m currently working on a book highlighting this amazing legacy and bringing the recipes into a modern kitchen. Sign up to my newsletter here to receive insights from my research.
Hi Alison
A really interesting and informative article. Though I live in the UK, I’d never heard of Staffordshire oatcakes, sowans and swats. Fascinating!
I’ve a couple of comments from the perspective of reducing the phytic acid in oats. I realize that this isn’t a topic you specifically addressed in your article but it’s one that’s been discussed by WAPF on various occasions and one which came to mind when I read your article!
The first relates to “kilning”. As you’ll know, modern-day oats are kilned in order to denature the enzymes and, thus, “stabilize” the oats. Before entering the kiln, the oats are steamed, as the combination of steam and heat is effective in destroying the enzymes, including phytase – the enzyme which breaks down phytic acid. Thus, when modern-day oats are purchased by the consumer and soaked, there’s no phytase to activate and, thus, nothing within the oats that can break down their phytic acid.
I was fascinated to learn from your article that, traditionally, oats were “carefully kiln-dried”. (I’d be very interested in your source for this.) And I initially wondered whether the consequence of this traditional kilning was also to destroy enzymes. But my guess would be that folks in traditional societies wished not to destroy the vitality of the oats but simply to dry out the groats to aid storage and/or milling.
And, when I revisited a paper about modern kilning, I read that the oats are first steamed because dry heating isn’t a good way of reducing enzyme activity. So I’m guessing that your use of the word “careful” implies that, in traditional societies, the kilning was a form of dry heating that was vitality/enzyme-preserving. Would this be your view?
My second comment relates to fermenting oats. I appreciate that opinions vary as to how problematic an anti-nutrient phytic acid actually is. So some may not be concerned about getting rid of it. But the below are my thoughts assuming that one does wish to do so!
Given that store-bought oats will have been kilned, the only vehicle for reducing phytic acid is an additional ingredient. Rye is the grain with the highest level of phytase. But if a sourdough starter is made from store-bought rye flour, the flour won’t be freshly-milled. Indeed it may be weeks or months old. And so, as I understand it, the phytase in the flour will have been destroyed by its exposure to oxygen.
Thus, it seems to me that, if one wishes to reduce/eliminate the phytic acid in porridge and one’s using store-bought oats, the only option is to mix some freshly-milled flour such as rye with the oats and to leave the mixture to soak/ferment overnight or longer. (This is what I currently do. I purchased a cheap manual coffee grinder and grind up some rye groats to add to my oats.)
An alternative would be to try and get one’s hands on some non-heat-treated groats and to soak freshly-milled oatmeal. (I’m currently trying to hunt such groats down!) However, as oats are fairly low in phytase, it’s probably still necessary to add some freshly-milled rye flour to provide enough phytase to break down all the phytic acid in both the rye and the oats.
Hi Richard,
Thank you for this very interesting comment. I appreciate your words and will try to give you my thoughts…I’m currently researching for (hopefully) a book on oats, so this is very much on my mind!
Regarding traditional kilning, I can’t find any evidence for steaming, only dry heat. And yes, with the ‘carefully’, I meant with respect for the grain – trying to preserve its nutrients (rather than zap it for long-life and profit). My research points to dry-kilning being done for two reasons – to make it easier to hull the oats and to bring out their flavour.
Phytic acid has been somewhat of a puzzle for me. I wrote this article with some ideas of how the Scots could be so healthy when visited by Weston Price, and yet not appear to ferment their oats: https://ancestralkitchen.com/2023/04/12/why-didnt-the-scottish-routinely-ferment-their-oats/
I love the article by Ramiel Nagel on the WAPF blog about phytic acid and I wish he was still around so that I could chat with him about his amazing research!
I also agree that views on how harmful phytic acid is are mixed. It is an anti-oxident, it only potentially stops nutrient absorption during the meal that it is eaten with and only ‘some’ (who knows how many/few?) people have issues. I don’t eat oats three meals a day and it appears at least some (and a large some) of the Scots (who did) were OK…so the jury’s still out there.
I agree about the rye and I use rye sourdough starter with my oats. I didn’t know that air exposure destroyed phytase though (do you have a reference for that – I’d be interested!).
If you are in the UK you *can* get un-heat-treated oats. Hodmedods sell naked oats. The variety has a paper-like husk which doesn’t need removing with heavy machines and therefore the groats don’t need stabilising. I’ve also sourced these from a farmer here in Italy and I’ve been sprouting (which according to one source I have read completely eliminates phytic acid), roasting, brewing and generally loving them!
Hi again
Very interesting that one purpose of traditional kilning was to assist with dehulling of oats. By contrast, in modern-day processing, dehulling appears to be a purely mechanical process and kilning takes place after oats have been dehulled. The purpose of kilning is to prevent oats turning rancid.
Compared to most other grains, oats are high in both fat and enzymes that break down the fat. In a raw groat, the fat and the enzymes are kept away from each other but if a raw groat is processed by, for example, being put through a roller, the fat and the enzymes meet, resulting in the oat becoming rancid. Thus, kilning stabilizes oats by destroying the enzymes that break down fat, so preventing rancidity and ensuring a long shelf life. Raw naked oats will turn just as rancid as raw clothed oats when processed and so, as I understand it, they’ll be kilned in the same way.
This paper gives an excellent account of the various stages in the commercial processing of oats.
https://digitalcommons.unl.edu/cgi/viewcontent.cgi?article=1028&context=nutritionfacpub
And here are a couple of other docs relating to commercial processing that I stumbled across, parts of which might be of interest.
https://core.ac.uk/download/pdf/14916332.pdf
https://consult.environment-agency.gov.uk/psc/nn14-1fl-navara-oat-milling-ltd/supporting_documents/Application%20Bespoke%20%20Supporting%20%20Document%2010062022.pdf
Again thanks for sharing the papers. Most of what I looked at concurs with the detailed milling information I read in the great book ‘The Oat Crop’. There are some very detailed diagrams/explanations in this book – when I first read it, I was truly surprised by the level of processing involved in modern oats.
I’ve just got hold of an old copy of Findlay’s book ‘Oats: Their Cultivation and Use from Ancient Times to the Present Day’ and I’m excited to contrast the traditional kilning technique (hopefully) described in there to this modern processing.
I haven’t had the chance to read through your second and third documents fully yet, but they are of interest. I am planning to write a historically-inspired book on oats and knowing the environmental costs of an industrial plant will give me some perspective.
The raw naked oats I buy here in Italy (and the ones Hodmedods sell, plus ones I’ve researched in the US) are whole (i.e not rolled or cut) and untreated. They sprout fine, so I know they haven’t been subjected to the 100C heat of standard oats. I’ve never seen a rolled version of them – and I guess that’s because they’d need to be treated if they were rolled and one of the big advantages of them is that they have the paper husk so don’t need to go near big machines!
Hi Alison
Many thanks for your thoughts. What I’ll do is respond to various issues you raise in various posts to keep the length of each post down.
I’ll start with the issue of whether oxygen destroys phytase. You ask if I have a reference and the answer is that, whilst I have various references, they’re not quite as definitive as I’d like!
As general background, and according to this article
https://phys.org/news/2011-10-oxygen-inactivates-enzyme-function-phases.html#:~:text=A%20large%20number%20of%20enzymes,electrons%20into%20technically%20usable%20hydrogen.
it’s the case that “A large number of enzymes…are known to be irreversibly destroyed by oxygen”.
With regard to enzymes in grains, a starting point is this fascinating, delightful article by Dr Johann Schnitzer about how he reintroduced real bread to a village in the Black Forest.
https://www.dr-schnitzer.de/vkernb01.html
In the article, Schnitzer writes: “From Professor Kollath I knew how important it is to grind the cereals only shortly before using them for bread dough or other food preparations – to avoid loss of health values by oxidation and enzymatic decomposition.” Kollath was a German bacteriologist and food scientist considered a pioneer of whole foods. See his Wikipedia entry.
https://en.wikipedia.org/wiki/Werner_Kollath
What Kollath said is, I think, suggestive of the fact that phytase is destroyed by oxygen. And, in Ramiel Nagel’s article “Living with Phytic Acid”, he pretty much says this, writing that “Fresh flour has a higher content of phytase than does flour that has been stored [32]”. (Presumably, storage results in a reduction in phytase content as a result of exposure to air/oxygen.)
Howeer, Nagel’s statement isn’t definitive because when one looks at his Reference 32
http://www.eap.mcgill.ca/publications/EAP35.htm
nowhere do the authors explicitly say that the phytase content of flour reduces over time. (The word “phytase” appears only once in the entire paper!) However, it might be reasonable to infer it from what’s said in the paper, particularly the section “Advantages of fresh flour”. In that section, the authors quote a study by Bernasek which blew my mind! They write
“The nutritional importance of using fresh stone-ground grains for bread-making was revealed in the results of feeding studies in Germany (Bernasek, 1970). Rats were fed diets consisting of 50% flour or bread. Group 1 consumed fresh stone-ground flour. Group 2 was fed bread made with this flour. Group 3 consumed the same flour as group 1 but after 15 days of storage. Group 4 was fed bread made with the flour fed to group 3. A fifth group consumed white flour. After four generations, only the rats fed fresh stone-ground flour and those fed the bread made with it maintained their fertility. The rats in groups 3 to 5 had become infertile. Four generations for rats is believed to be equivalent to one hundred years in humans.”
Given all of the above, I’m pretty convinced that once grains are milled, the available phytase will reduce over time, probably quite rapidly. However, I’ve been unable to find an academic paper that states in black and white that phytase is destroyed by oxygen. It would be a straightforward study to mill some flour and then test the phytase content after, for example, 1, 2, 3, 6, 12, 24, 48 hrs etc. I’m somewhat surprised that it hasn’t been done!
But if, as I suspect, phytase is destroyed by oxygen, then store-bought rye flour is, regrettably, not a source of phytase!
Thank you for sharing your research! I read most of it and I would agree it’s feasible to assume phytase degrades with exposure to oxygen. I don’t yet have an easily-usable grain mill (I’ve wanted one and been hovering on it for a good two years) and more than anything this research makes me want one.
I extrapolate this to the conclusion that unfermented freshly-ground rye flour is better (from a phytate perspective) to put into soaking oats than using a sourdough starter that has been made with freshly-ground flour but is a few days old. Would you agree?
How did you end up diving into this yourself? You’ve done quite some research!
REPLY #4
Hi Alison
Many thanks for your replies. I’ll respond in multiple parts again!
Your planned book sounds great. I’d be fascinated to read about the history of oat cultivation and use. The Findlay book sounds like it will be helpful. And “The Oat Crop” book is certainly comprehensive!
I’ve been interested in traditional methods of preparing food for a good while. Some years ago, my auntie was living in the US and happened to meet Sally Fallon! I think it must have been around the time that the second edition of “Nourishing Traditions” was released because my auntie returned to the UK with several copies which I think she’d been given by Sally. Anyway, my auntie was kind enough to give me a copy and I found it unbelievably interesting. I think that must have been my route to discovering Weston Price and to learning about phytic acid!
Anyway, fast forward to a couple of months ago when I got back into eating porridge for breakfast. And for some reason became slightly obsessed with getting to the bottom of what it would take to remove phytic acid from oats. I’d previously read Ramiel Nagel’s article on phytic acid and I revisited it and started following up various references. (And, as I used to work as a university researcher – though not in the nutrition field – I’m happy reading and searching for academic papers.)
And it turns out that one has to get one’s head around quite a lot of stuff to understand how to remove phytic acid from porridge. For example, one has to understand that soaking commercial porridge oats is a fruitless activity because the oats have been heat treated and the phytase destroyed. And one has to understand that store-bought rye flour is not a source of phytase as phytase is destroyed by oxidation. It took me a long time to get clear on this. And not everyone is. For example, I was somewhat surprised to discover that Sally Fallon released a video not too long ago in which she suggests that soaking shop-bought oats with shop-bought rye flakes will get rid of the phytic acid.
One also has to understand that even if one can get hold of raw groats, removing phytic acid – at least in the absence of fresh rye flour – isn’t altogether straightforward. For example, I learned from Nagel’s article and following up his references that sprouting raw oats doesn’t reduce phytic acid by very much. For example Egli et al (2003) soaked groats for 16 hours at 25C and then germinated them for three days in the dark at the same temperature. There was no reduction in phytic acid content after the soaking. Or the sprouting!
https://ift.onlinelibrary.wiley.com/doi/abs/10.1111/j.1365-2621.2002.tb09609.x
And Larsson and Sandberg (1992) found that soaking oats for 7hrs at 23C and then sprouting them for 5 days at 11C reduced the phytic acid content by only 19%.
https://ift.onlinelibrary.wiley.com/doi/abs/10.1111/j.1365-2621.1992.tb14340.x
What about soaking raw oats? Well, as Egli et al’s paper shows, soaking whole groats won’t get you very far. You need to process the groat, for example by milling. Nagel references Frolich et al (1988) who milled raw oats into a flour, mixed it with water and incubated it at 37C (the optimal temperature for phytase). After 22 hours, the phytic acid content was reduced by 65%.
https://www.sciencedirect.com/science/article/abs/pii/S0733521088800481
Another paper I found by Fredlund et al (1997) – this one’s not referenced by Nagel – also experimented with incubating raw oat flour and water. They found that incubating flour made from dehulled oats with water at 20C for 17 hours reduced phytic acid content by 73%. And incubating flour made from naked oats with water at 20C for 17 hours reduced phytic acid content by a whopping 90%.
https://www.sciencedirect.com/science/article/abs/pii/S0733521096900703
Going back to the Larsson and Sandberg paper, they also experimented with a combination of sprouting and soaking. They took their sprouted oats, ground them into flour, mixed the flour with water and incubated for 17 hours at 20C. Phytic acid content was reduced by 94%. (They used hulled rather than naked oats.)
(The range of experiments conducted by Larson and Sandberg and by Fredlund et al are wider than I describe: I’ve just pulled out some relevant highlights. So it’s definitely worth reading the papers.)
I suspect Frolich et al and Fredlund et al will have ground their oats into a flour that was at least as fine as shop-bought fine oatmeal. But I suspect that most folks want to make their porridge with something coarser – jumbo oats, rolled oats or a coarser oatmeal. And I don’t know what reduction one would get in phytic acid if, at home, one put raw groats through a flaker or ground them coarsely in a flour mill and then soaked them for, say, 24 hours. And of course it may depend on the variety of oat used as well as the method of processing. But without adding fresh rye flour, I’d guess one could get a reduction of 50+%. (But it’s just a guess!)
Of course, adding sufficient rye flour should guarantee destroying all the phytic acid but some may prefer the flavour of just oats. And I don’t know what ratio of rye flour one has to add to commercial or raw oats to destroy all phytic acid. I make my porridge using 50g of commercial rolled oats and 10g of fresh rye flour. But, again, it’s just a guess!
It would be great if one could get some university researchers to elaborate on the experiments done by the likes of Frolich et al and Fredlund et al so as to bottom these issues out!!
Wow, Richard! I can tell you used to be a researcher 🙂
I couldn’t see the 20C details in the abstract of the Fredlund paper, so I’m guessing you pulled that lower temperature from the full text?
I’m convinced that it’s not feasible to completely and/or reliably neutralise phytic acid in (even raw) oats by plain water soaking/sprouting in a ‘normal’ kitchen. I also think you have convinced me to get a grain mill – I’d been on the fence for several years.
I think there’s room here for determining how much of an issue phytic acid actually is for humans who eat it once a day. I question this partially because of figures like that which I read here https://www.kitchenstewardship.com/whole-grains-phytic-acid-the-role-of-phytase-soaking-grains/ that potentially a large portion of phytic acid is degraded in our intestines (this figure is gut biome dependant, I think, because certain lactobacillus species produce phytase) but mainly because in all of the many oat dishes from traditional British cultures that I’m studying for my planned book, virtually none are soaked/sprouted/fermented – and these peoples in many cases subsisted on oats.
I wonder if this is something like what’s happened to wheat. We’ve abused it and now it is a large problem in our society. Perhaps, back then, with wise life choices, phytase wasn’t so much of a problem?
I agree that the WAPF video is misinformed. It is not the first time I’ve seen this and a few other people have picked it up too.
REPLY #5
Many thanks for alerting me to the fact that the naked oats sold by Hodmedods are raw.
Prior to you alerting me, I’d come across a UK retailer advertising its groats as non heat treated. The groats weren’t advertised as naked so I assumed they were covered. At this point I was aware of how covered groats are processed and so wondered whether non-kilned, covered oats might be too good to be true. So I asked if the seller would be kind enough to check with their supplier that the groats were indeed unkilned. The supplier replied that the groats were, in fact, kilned!
Exploring Hodmedod’s website, I discovered this interesting blog post about naked oats from 2021.
https://hodmedods.co.uk/blogs/news/naked-oats-are-a-disruptive-technology
It points out that because dehulling covered oats is a “tricky” process, it’s now done centrally at the large oat-processing plants. So while I can see how all covered oats end up at such plants, in theory there’s presumably no reason why dehulled groats couldn’t be sold unkilned (as rancidity seemingly becomes an issue only when groats are processed by rolling, cutting and milling). But, in practice – perhaps because there’s limited demand for raw groats! – it would seem that all the dehulled groats sold in the UK for human consumption are kilned.
I’d wrongly assumed that, along with covered groats, naked groats are also used by the big producers to make porridge oats and so forth and so would also be kilned. But, as the Hodmedods blog points out, these days naked oats are, in fact, grown as animal feed. (And I think it’s the case that oats used for animal feed, both covered and naked, aren’t kilned.)
The Hodmedods blog also notes that because naked oats don’t need to be hulled and so don’t need to be sent to large processing plants, they can, in theory, be purchased directly from a farmer for human consumption. However, in practice, that’s not been straightforward.
“Though not a new crop it’s proved very difficult to get naked oats onto plates and menus. This is because they’re grown almost exclusively for animal feed (because they’re so nutritious) and getting hold of seed and growing them (legally) is incredibly difficult; big grain trading companies control the supply of seed and generally only release it on buy-back contracts which ensure they maintain control over both seed and harvest. We’ve been working with naked oats for 5 or 6 years, but it’s only in the last couple, working with Turners of Bytham and with seed support from Cope Seeds that we’ve really made any progress. From this Autumn we’ll have plentiful supplies of organic naked oats.”
How fascinating! And, as you explain elsewhere on your website, naked oats are indeed not new, being grown in Cornwall in centuries past and being used to make gerty-milk!
Wikipedia tells me that the roasted “pillas” were said to have been “scroached”! And that the large pebble used to grind the scroached pillas was known as a “bowel”!
https://en.wikipedia.org/wiki/Avena_nuda#Pillas
Anyway, thanks again for the Hodmedods tip off. Very much appreciated. I shall be making a purchase very shortly!
Hi Richard,
I can’t be completely sure, but I think perhaps the oats are damaged too much to avoid kilning *before* they even get to the rolling/grinding/cutting stage. The milling chapter of ‘The Oat Crop’ explains that the groats are ‘clipped’ top and bottom prior to cleaning/sorting to facilitate the hulling. It then goes on to talk about the impact mills and their removal of husk by literal smashing of the oat against the side of a container. Later in the chapter, when talking about the reason for kilning, it says that ‘bruising’ can cause the rancidity reaction to begin. Taken as a whole I think even before the oats are milled they are damaged to the point where they need kilning.
I’m saddened to read the issue with the naked seeds Hodmedods had and am glad they have overcome them. Interestingly, the revivalists of black oats (they aren’t naked) in Wales have had issues with hulling because the large oat mills will not take anything less than very large industrial quantities of grain.
I’ve just written a blog post on gerty milk (which I found out two days ago was also made in Brittany where pillas was also grown) which will post on Tuesday. You could have a go with your naked oats if you wanted?!
REPLY #6
Like you, I’d guess that fresh rye flour has more phytase than a two-day old starter made from the same. My guess would be that, whilst the water in the starter would reduce the starter flour’s exposure to oxygen, it wouldn’t eliminate exposure completely and so, over the two days, there would be some breakdown of phytase. Don’t know if this makes sense?
One approach might be to add fresh rye flour to the oats along with a little of the starter. The starter would get the fermentation going more quickly, thus more quickly creating the acidic environment which aids phytase activity.
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A grain mill’s definitely on my wish list. I decided I needed to get one after reading this article on the Perfect Loaf website making the case that bread baked with freshly milled flour is both tastier and healthier.
With regard to taste, the author writes
“When I bake my typical sourdough bread with added freshly milled flour, it takes on added levels of flavor complexity, a taste that is hard to capture in words but brings a smile to my face. The crust becomes incredibly thin and crackly with a forward shine to it, a shine that almost looks as if I had smeared the bread with olive oil and then baked it. The interior of my loaves are tender, light, and with a vibrant flavor. I’ve read others describe this flavor as “nutty” or “grassy,” and I’d agree, it’s fresh and alive.”
And with regard to health, the article references the EAP paper I’ve linked to previously (http://www.eap.mcgill.ca/publications/EAP35.htm) that describes the Bernasek rat study. (I subsequently discovered that Rami Nagel references the same paper.)
The author also describes how he’d purchased a manual “GrainMaker” mill. Too big (and expensive) for my small kitchen but impressive…and very red! Apparently, the company sells a kit that allows their mills to be powered by a bicycle!
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Some oat trivia. Whilst searching the web for raw oats, I came across this product, on sale in Australia: rolled oats made from unkilned groats!
https://www.aussiehealthproducts.com.au/lotus-organic-raw-rolled-oats-750gm.php
The shelf life is three months. But, if oxygen is the enemy of phytase, then, sadly, I’m guessing these oats may quickly become phytase-free.
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What I find particularly odd about Sally Fallon’s video is that it fails to draw on the content of Rami Nagel’s article on the WAPF website!!
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My research has been mainly focused on how to remove phytic acid from oats. But, as we’ve discussed, there’s the (crucial) prior question of how big an anti-nutrient phytic acid actually is. Like you, I think that, if the food processing techniques of the Scots didn’t (much) reduce phytic acid, then perhaps phytic acid’s not such a big deal?
In a similar vein, I’m pretty sure that the traditional process of nixtamalization would have destroyed the phytase (and all the other enzymes) in corn. And yet the various native populations in the Americas seemed to do OK.
Your Kitchen Stewardship link is interesting. When I’ve had a chance to study it further, I’ll perhaps write something more.
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What you write about the clipping and bruising of covered oats necessitating kilning is really fascinating. Thanks for that. I’m presuming that, traditionally, there must have been a method for dehulling oats that didn’t damage the groats so that they could be stored for use in the months after harvest. And from what you’ve previously written, traditional kilning – prior to dehulling – was an important aspect of that method.
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I shall look foward to reading about gerty milk!
Hi Richard!
Without further developments/research sadly I don’t think we’ll answer the question of whether phytic acid is really a problem. But my (informed) hunch is it’s not as much of a big thing for most people as WAPF makes out. It’s an interesting parallel about nixtamalization.
I have ordered a grain mill! You totally convinced me 🙂 Yes, I’m looking forward to putting fresh rye in my oats (perhaps along with some starter), but I am also excited about milling oats into meal, rather than flaking them.
I love that grinder! I remember seeing something like that hooked up to a bicycle on on of the Instagram community grain projects last year.
The Auz oats are interesting – but yes, like you say, without phytase.
Did you see my blog post on gerty milk? I managed to get some naked oats from Hodmedods whilst I was in the UK and I’m going to have another go at the process with those.
One of the documents you sent (the Gates dissertation) had a sentence in it that made me stop. On page 28 there is an (unreferenced) sentence that says heat alone is not as effective as a method of destroying lipase as steam heat. I then found something in the Findlay oat book that explains that in past days oats were dried to 3-5% moisture and stored well, but that ‘now’ (i.e. 1956) they are dried to 6-8% moisture and that these oats, if kept for sometime develop a “somewhat bitter taste or ‘nip'”.
I found this interesting; moisture content affects storage quality – I knew that, but the fact that the oats weren’t being kilned enough to destroy lipase and hence at this moisture level went bitter perhaps indicates that the Scots didn’t destroy all their phytase in the kilning?
And a quickie about your paragraph on the clipping and bruising. I would extrapolate, from my reading, that after harvest the oats where stored on the stalk in the stook. When sent to the mill, they were processed all the way (i.e. hulled and ground); none were hulled and then left without grinding. There is much writing about how the harvest would come into the home and the huge supply of meal would be put into the wooden storage box and tramped down really tightly to exclude as much air as possible (sensible, right ;-)). I have yet to find anything about storing groats/going back to the mill.
How are you getting on with the Hodmedods oats?