Hi Vincent,

I don’t know why it was done, but I know it was. My specific information comes from a book by Findlay: https://www.amazon.co.uk/Oats-Their-cultivation-ancient-present/dp/0902604058 If you could get hold of a copy it might help.

I’m coming at this from an historical and culinary perspective so haven’t looked into the details. I can see how your differing angle would want to investigate more!

Re fermentation, the original Scottish oat ferment, sowans, was created to use up milling ‘waste’. The process made food out of otherwise unusable goods and I guess people worked out that it was also particularly digestible.

Hi Alison,
Thanks for the link.
I have never tasted fermented oats and your article indicates it improves digestibility. I presume this was discovered by accident, it certainly could not have been scientifically discovered. Other than digestibility was there any other driver for fermentation?

From my research into kilning there is evidence going back over a thousand years in Ireland but I guess these were communal kilns. I never heard of small farms having their own kiln but I have not investigated this.

You mentioned drying oats down to between 3% & 5%.
Why was this necessary (12.5% is sufficient for storage) ?
How did they measure that 200 years ago?
Does that not damage the nutrient content of the grain (Oats contains oil which will evaporate at high temperatures)?
Or are you referring to modern kiln driers?

As back ground here, I have experimented with hemp seed and built my own drier because hemp seed needs to have its moisture content reduced to 8% within 24 hours of harvesting in order to prevent it going mouldy. If one reduces it too low one loses the oil content of the seed rendering it partially useless. Here is a link to my google drive with the design details and some operational videos which I will leave up for a few days and you can download for informational purposes:
https://drive.google.com/drive/folders/17Q1vKJN10iDb43g8oWTI7fhZsS7eEmBT?usp=sharing
Since then I have switched my attention to oats!

Hi Vincent, it’s Alison here. I’m currently researching traditional harvesting, kilning and milling of oats for my forthcoming book, so I’ve got this at the forefront of my mind right now.

You’re right that it was much easier to mill and store oats if they were kilned. I’ve read that in the past, they were often dried to between 3 and 5% moisture.

How wonderful that you have your grandfather’s memories of oats. My research into the transition from home-kilning/quern-grinding to large mills with kilns attached shows that very often the oats were kilned at the farm then sent to the large mill. For the mill your grandfather used I would think that before the kiln was attached to it, farmers dried their own oats at their farm before sending to the mill.

Regarding the phytic acid question, this article of mine might help: https://ancestralkitchen.com/2023/04/12/why-didnt-the-scottish-routinely-ferment-their-oats/

Hi Richard,
I realise I am interjecting here in your conversation which I find very interesting as I am currently trying to understand how oats was processed and what really happened in the old mills going back centuries.
Kilns were used to dry the incoming grain for storage purposes because of the wet climates in northern Europe, moisture content had to be reduced below 14% (ideally 10%-13%) for storage purposes to prevent mould, even animals will not eat mouldy oats.

In the job lot mills, grain was often stored for farmers until they need it, hence the kiln. Also high moisture grain would have a tendency to stick to grinding stones. The kiln may have had other unknown side effects in the period which reduced Phytic acid but I doubt it because steam cleaning is at a much higher temperature than kiln drying. Most mills were job lot mills because tenant farmers were forced to use the mill of the local land owner and distance also meant people had to use local mills.

According to google, Phytic acid was discovered in 1903, and the first enzyme was discovered in 1833, so these were not a consideration in the process pre dating 1833. The old mills did not steam clean anything as far as I can determine as there was no reason to. Steam cleaning also extends shelf life which was not a problem in the past.

I remember my grandfather telling me he took a sack of oats (probably 112lbs) to the local mill and collected oaten meal a few days later. This mill is 200 years old (now disused) and had no kiln for the first 100 years of its existence, it had a kiln only for the last 100 years of its life which overlapped with my grandfather’s life. This oaten meal lasted a considerable period of time (probably 2 months) without going rancid, but I don’t know this for a fact.

According to this article https://www.webmd.com/diet/foods-high-in-phytic-acid phytic acid does not affect healthy humans but can large amounts can block the uptake of Calcium, Magnesium, Iron, Zinc, etc. If people have been eating oats for thousands of years isn’t it reasonable to conclude that neither Phytic acid nor the related enzymes affect them?

Hi Tania,

This is a good question.

I know rye is high in phytase. I don’t, however, know about its phytic acid levels or about phytase’s interaction with phytic acid and how much is needed to neutralise it. As far as I know, there haven’t been any studies on this.

I agree that nature provides us with solutions but I’m also aware that nothing evolves in isolation and that other plant and animal food would have been eaten with rye and other grains.

I don’t have a precise answer to the phytic acid question. This is why I suggest other strategies to potentially combat phytic acid – adding a live starter which produces phytase and eating your oats with vitamins C which mitigates iron problems. Neither do I do all of these things all the time, because I think that phytic acid has some positive benefits to.

I am hoping you can clarify something for me… Rye is used because it contains high quantities of phytase. How do you know that rye contains sufficient phytase to neutralize the phytic acid in the rye itself AND in the oats?

I feel like nature provides everything in balance… Such that the rye would contain sufficient phytase to neutralize the phytic acid already contained in the rye itself. But doesn’t it contain phytase in excess that could neutralize more phytic acid beyond what is contained in the rye itself?

This is what is puzzling me… Do you or Richard have any studies on this that would suggest there is “leftover phytase” once a portion of it is used to neutralize the phytic acid in the rye itself?

Both of you are so lucky to have access to the Hodmedods Naked Oats. Unfortunately they don’t export to Australia. I too would like to know the results of the Naked Oats please. If I find naked oats in Australia, does it matter the type? Apparently the Hodmedods are Turners of Bytham Cope Seeds. Here in Australia I can only find Simpson’s Malt Naked Oats and according to Hodmedods, they tried the Simpson oat and said they were too lightly malted for their taste. However, I would assume theyre talking on the subject of brewing beer. Do you think it would make any difference for porridge?

You mention bacteria thrive at temperature between 20-24C and that 22C seems to work well for you when it comes to Fermentation of grains (using live culture, e.g. sourdough starter), and although this temperature seems to work well for bacteria, how is this helping with enzymatic degradation of phytic acid since the temperature optimum for phytases range between 25-80C and active within pH range 4.5 – 6.

Is it because you’re relying on the Rye in the sourdough starter to degrade the phytic acid rather than relying on the temperature itself? Also, if Sourdough starter pH is 3.5-4.5 how can we be sure it’s reaching the higher optimum pH of 4.5?

Do you know if whey pH is 4.2 – 4.6? As for Apple Cider Vinegar, pH is 2.5 – 3, this doesn’t seem at a high optimum range to be considered. What are your thoughts on this? Have you used whey before? Can you describe the taste difference between whey and sourdough discard?

So far I’ve only been using the ACV and whey methods and adding rye flour to the oat but I would like to try the rye sourdough discard but I’m a little nervous as I haven’t worked with sourdough starter before. I’m still researching before delving into this.

Also, do you know what might be giving a bitter after-taste of the cooked oats (experienced after soaking with apple cider vinegar)? Please note, I have been soaking overnight using a temperature controlled water bath (sous vide) with the contents enclosed in a plastic bag. Do you think it might be because the contents isn’t breathing? How important is it that the oats ferment with a lose fitting top?

I apologise for so many questions and I really hope you can help me.

Hi Mina,

Naked oats are a different genus and grow without a thick hull.

Your question about the hulled oats needs further investigation. The abstract for the paper does not talk about this particular result (only the results at 37C). Richard was able to read the whole papers, but I am not affiliated to any university/company so can’t get access easily hence I haven’t seen it.

Thanks,
Alison

Hi Richard/Ali,

Why would the 73% reduction in phytic acid be higher in the dehulled raw oats if removing the hull damages the grain, hence exposes to air, then going rancid?

If Naked Oats reduces PA by 90%, would this be the better choice? And, why don’t naked oats have the hull? I’m new to all this and still researching so please excuse my lack of knowledge.