Factors Affecting Water Chemistry Calculations

[Peebee]

I have been quietly crunching these water compositions. Time to start getting noisy again.

I'm finding the results (so far) very revealing. I have for years (since pre-Covid times) been mystified by low pH levels in my mashes (lower than pH 5.0) and getting nowhere trying to explain it ... or finding others on various forums to explain it for me. But these "tests" over the past couple of days have been turning up plenty of explanations and corrections.

They are tests, performed on a calculator (Bru'n Water), and will need confirmation from real brew trials. I'm only outlining what I'm up to here on the chance that someone has already done the work (so I won't have to!). There are no hundredths of a gram! Although I did use "hundredths of a gram of get the rounding going the right way.


I already brew "full-boil-length-mashes". Using "Grainfather" setups ("full metal jacket" BIAB ... with recirculation). My 70L 3V System has been out-of-commission for over a year. All these recent tests have been "full-boil-length-mashes". Mashing like that appears to have exacerbated my problems so I couldn't reach a swift resolution.

The following tables are rough, unfinished, and need a bit more smoothing out. Using what @Silver_Is_Money refers to as "quasi-empirical" techniques; I had to look that up:

quasi-
/ˈkweɪzʌɪ,ˈkweɪsʌɪ,ˈkwɑːzi/
combining form

1. apparently but not really

Oh wow! Got to have some of that (it's right up my street!).

I'll need to fill in some more scenarios too. Then crunch the whole lot down into a simple tool (Spreadsheet). Meanwhile, what I'm doing is stripping some, what I consider, are un-necessary variables, i.e. most of the salt additions in the mash, and the free-for-all mash-thicknesses to just two? Maybe an in-between third? Calcium additions to be fixed, I'm counting on 35ppm Ca being sufficient for the mash (as CaCl2). Alkalinity remains a variable, but its limited scope in these situations ought to make it easier to handle? All other additions for the boil where their influences, not being mash specific, wont impact the mash (like the effect of Ca and Mg on mash acidity, the source of many of my current issues.).

This is the table extracted (full boil length mash) so far:

Divided Yellow, Amber, Brown and Black. Goes to 50SRM black, which is the limit for Bru'n Water. Alternative for somewhat unpredictable Acidulated Malt is provided wits Phosphoric Acid (81%). The pH predictions are what I'm mainly stealing from Bru'n Water, but I do appreciate what a notoriously tricky task it is pairing pH with a handful of salts.

More than enough fo now ... I'm off to bed! The question is ... there will be those who've trodden this path before ... I hope to learn the pitfalls before embarking on this much further. I'll attempt to explain more (if neded) tomorrow?

Thanks.

 

[VikeMan]

If your goal is to fix your mash pH problem by developing a mash pH program that predicts pH using SRM as a factor, it's been done. Many years ago. John Palmer made a spreadsheet. You might even be able to download it from the Wayback Machine or somewhere. It sometimes worked well and sometimes didn't. The biggest problem (there was more than one) with the model was that Crystal Malts and Dark Roasted Malts have very different acid contributions "per SRM contributed." The models have moved well beyond the SRM model that John himself would today admit was primitive and sometimes wildly off. The model that you are working with, Bru'nWater, is far superior, as are several other modern models.

 

[Peebee]

If your goal is to fix your mash pH problem by developing a mash pH program ...

Thanks very much!

Yeap, it came to that (developing a mash program), but I've been on that for years and come nowhere near a solution until being forced to discuss it openly in this thread (slightly off-topic too ... fortunate that I'm the OP's author). I know of John Palmer's stuff and was being quite rude about it; I'm happy he would consider the old stuff was "primitive". But Bru'n Water is what I'm going with to model the tentative connection of "pH" with mash ingredients. (I will be asking him for permissions ... when I know what it is I'm trying to steal).

I do want to steal Mr Palmer's "Structure" stuff, because although he dismisses "Firm" as only describing two beers he knows of, he casually ignores virtually all of British traditional brewing (and I'm a Brit with traditional British beer tastes if you haven't noticed ... "traditional" means not 1960,70s+ British "keg" stuff which comes from, gawd knows where!). Including "Structure" ensures I'm not being "exclusive" in what I'm trying to do

But it's Chris Colby's work I want to model around ... dead simple; even suggests "teaspoons"! There's some evidence of that connection in the tiny table I created above ... the colour divisions are his. (Although I pushed it out to 50SRM which isn't fitting too well ... a bit of "cherry-picking" is in order, which brings me onto ...).

And @Silver_Is_Money; the person who put me on this track many moons ago by making me appreciate the difference between specific gravity and density (in grams per millilitre ... well, they look nearly the same). (SG? What's that got to do with it?). I'd like to use his work, but all that "DIpH" stuff does come with a painful amount of ongoing physical maintenance. But I take heart from his scribblings:

... Cherry picking, empirical method, quasi-empirical mishmashes of math modeling and made up stuff, and strict math modeling all seem to wind up within relatively the same ballpark as to prediction. ...

Could be worse! Your own (@VikeMan) spreadsheets haven't escaped my attention. But I haven't had time to mess with them, so they're safe. ... For now
Cheers.

 

[MaxStout]

I'm curious to see where you go with your new water program, @Peebee, though I'm not sure what improvements can be made beyond what Bru'n Water already does. Maybe you've got an angle that needs to be explored? Do you have the paid version of Bru'n Water? Well worth the modest cost.

 

[Peebee]

I'm curious to see where you go with your new water program

Good grief, no, no, no! I'm not attempting to better Martin's program. I can't even attempt what I'm doing without using Bru'n Water myself.

It's connected with what I started this thread with ... that some of us (which has included me) are losing their sense of scale: Confronted with a tools like Bru'n Water that is perfectly capable of handling "hundredths of a gram" there are those who believe they must work with "hundredths of a gram", etc., or else turn out naff home-brew. Instead of a time saving tool, the likes of Bru'n Water is being used to waste valuable time that could be used in more useful pursuits, like drinking home-brew. In my case it was lack of control of pH (sub-pH5.0 mashes) ... Bru'n Water could indicate the problem if I knew what I was looking for (instead, I used Bru'n Water to work with more and more ludicrous "precision" because that was the problem, lack of precision ... wasn't it? ).

The "new program" (actually just a spreadsheet and, sort of, a "philosophy") is just a hand to step back from the brink ... and its throwing up loads of snippets that's keeping me from getting on with "more useful pursuits" ... ironic that? A spreadsheet will take weeks (months), for now I just want a framework.

 

[MaxStout]

I get that. I've made a spreadsheet where I keep various calculations, set up in a way that reflects how I do things. It's snowballed into this multi-tabbed behemoth over the past dozen years or so.

 

[Peebee]

I'm having a little trouble with my "scheme"; and it all goes back to my original post in this thread:

We measure our water salts to what we think is one hundredth of a gram (two decimal places of a gram). If we do that accurately we must be getting the water additions as originally intended for the style of beer being brewed. Should we not?

Yes, you should ... If your mash to water ratio is identical to the original's. If, your sparge water (and any top-up water) is treated to be identical to the original's. If, you collect identical proportions of wort as the original. If, your "boil-off" is identical to the original. If, ... is there more?

Otherwise, your "accurate" weighing out water salts is meaningless? Even tenth of a gram, or within a gram, makes little sense.

I was widely criticised for sounding off about something I provided no example of. But this time I have! No end of it, because the thread evolved into one describing what I was doing before my earlier rant, so I'm banging my head on what I ranted about again ...


In drawing up my "scheme" I need to establish a "working arena" of lots of example beer recipes which the "scheme" will cover (they will provide the data that the scheme's solution will be able to replicate). I'm using Bru'n Water to generate the numbers to use. The following example is from one such recipe where the "alkalinity" is being provided by 0.03g/L of Baking Soda (NaHCO3) to create an "Estimated Mash pH" of 5.45 (the water it is added to is effectively distilled). 0.10g/L of Calcium Chloride (anhydrous) is to provide a minimum Calcium concentration of 35ppm in the mash (derived from Internet searches):

(At this point the "scheme" is only modelling the mash and is not a completed recipe). All is well with this, a snip from a little further right in the Bru'n Water spreadsheet is:

The "Batch Size" is 19L (5 USgallons), you are I hope remembering this is modelling and not an actual recipe. This is a "full-boil-length-mash" ("no sparge"). Although I do use "no sparge", I can't expect others to be convinced, so I model for three different mash thicknesses. One is a half boil volume mash, a mash:boil ratio of 1:2. This translates to:

Humm, that's shaken it up a bit. Firstly the Calcium Chloride is halved in the mash, well below the "recommended" amount (the calcium is to react with malt elements, and the amount of malt has not changed). Easy fix, change the first of those "No" boxes to "Yes" and the salts portioned for the sparge are added back to the mash.

The "alkalinity" (as bicarbonate) has also been cut in half so it's now saying pH5.23 ... and worse, having increased the mash calcium in the previous step, the mash is predicted as down to pH5.16. A bit of twiddling (increasing the bicarbonate from 0.03g/L to 0.24g/L) and I can get pH5.45 again.

Humm ... but that's a lot of bicarb: 2.3 grams. By the time the recipe "iterations" are for "brown" beers pHs are into 5.5+ numbers the sodium (from all that bicarb) is well over 100ppm. My plans to create a "simple" approach to water calculations will require a good bit of work from me to get it right. I'll sort something, meanwhile ...

CONCLUSIONS:

Measuring precise amounts based on a hodge-potch of different measuring scales (concentrations like grams/Litre and "absolute" measurements like just "pounds" or "kilograms") is a Fool's Game. Stop doing it! Unless your absolute measures are paired with another absolute measure (e.g. "USpounds" paired with "USgallons"). And in particular: Stop instructing others using a mish-mash of different scales!

I'll go further than just rant at weighing "hundredths of a gram" ... even tenths of a gram ... even whole numbers! ... doing it is insanity in these situations.

I've learnt the hard way and wasted eons of time trying to sort the implications ... I do not recommend treading that path.


Has me "strawman" got some backbone now?

 

[VikeMan]

No, it doesn't. You still haven't provided an example of anyone insisting that you or anyone measure salts to any specific degree of accuracy/precision. If you mean that the Brun'Water model itself is forcing you to do anything, that's silly.

Your conclusions don't follow from your modelling example. The Bru'nWater model reacts to changes in inputs just like it's supposed to. There is solid theory and observation behind it. Go ahead and round your input/output numbers to your heart's content. Love or ignore the result. Or don't use the model at all. Nobody is forcing you, or has "beaten (you) over the head about it."

(Edited to be nice(r))

 

[Peebee]

You still haven't provided an example of anyone insisting that you or anyone measure salts to any specific degree of accuracy/precision.

I haven't?

You've got me ... because I won't pick any one person out as an example. And any calculator should be worded to avoid such a slip, as you've said. But there is one bit of software illustrated above which does mention "Recommended Range" for Calcium is 50-150ppm.

Now some things are "flavour enhancers" and some things take an active role in the Chemistry. Flavour enhancers should be specified as a concentration, like "50ppm", or, if you specify no additions in the sparge and the sparge contributes half the fluid in the final wort, the wort contains only 25ppm. That may be the intention, or maybe an unknowing slip?

Another example. The 50ppm is for something that contributes to actual chemistry. You calculate for your full-boil-length-mash (BIAB say) and your water needs 5g of ... Calcium salt say. You decide to mash convensionally in half the water. You put 2.5g (5/2) of the calcium salt in the mash. But the mash constituants other than water hasn't changed. 5g of Calcium salt should have been used. But that would have pushed calcium salt up to provide 100ppm calcium. Works both ways: I was caught out when moving to full-boil-length-mash, I stuck with the ppm amount of Calcium without appreciating the actual amount of calcium in the mash was doubling ... the Mash pHs were dropping through the floor!

No fault of Bru'n Water or anyone. Except! Whoever mentions "ppm", "mg/L", or whatever, as a value to use without providing the context to use it in.


Examples abound in this forum particularily (water chemistry). It doesn't need me to find one, you can find your own in no time at all. This sort of error won't be high-lighted, but there'll be plenty of suggestions to measure quantities to two decimal places.

(Not edited to be nicer, I think I'm being nice enough).

 

[VikeMan]

Ok, I'm done. I'm not going to try to understand another rant.

 

[MaxStout]

In Excel you can go to "Format Cells" and "Number" and select the number of decimal places you want to display. Never tried to (or needed to) in Bru'n Water, and maybe those fields are locked, anyway. But worth a try if you want to truncate down to 1 place.

 

[Peebee]

In Excel you can ...

I've not played much with all these "locked" settings either (in Excel), I just accept the default of "locked": You can't select the protected cell at-all. I don't know if any of these options would allow what you are suggesting or whether Mr Brungard has messed about with them.

But I'll try and take this moment to try and better explain what I was ranting about. I appear to have given @VikeMan the wrong idea, so I guess I've given others the wrong idea too? That would be unfortunate, as it would mean people who are making the mistake will be ignoring something they do need to know.

Repeatative writing out the problem also ensures I'm getting it right! It's very difficult to write something out from multiple angles if it isn't correct.


This is what I was moaning about in my previous posts. I'd like to make it perfectly plain: I am not saying Bru'n Water is at fault, or that the research work is at fault! Only our (as homebrewers) interpretation of the information is at risk. Because of our habit of mixing measurements and not appreciating when we cross-the-line. And I mean, measurements of concentrations with "absolute" measurements (e.g. "ppm" and "grams"), not imperial and metric.

These are clips of some of the work I'm doing that alerted me to making such slips. They are not complete, they contain no data intended for others to use. They only illustrate how I was made aware of issues. The tables covered aciculated malt additions (and the equivalent in Phosphoric Acid) and "Alkalinity" additions (as Sodium Bicarbonate) And the pH that Bru'n Water interpreted for the recipes (and its colours) picked on. Other water additions were a fixed amount of CaCl2 to provide minimal Mashing needs (35ppm Ca, still under review). The change between the two tables are the Mash thickness: 1:1 for the first ( [mash water] : [batch size)] ). The batch size and mash ingredents stay the same. Mash water type stayed the same, distilled water, containing the CaCl2 mentioned above, plus (*SPOILER ALERT*, this was the issue) a calculated amount of Sodium Bicarbonate as g/L or mg/L (calculated by Bru'n Water).

Batch is 19L (5 USgallons), mashes 19L and 9.5L respectively.

.

.

Suggesting 4.2g looked awfully suspicious! But note: Bru'n Water has only calculated what it was asked to calculate!


Writing all this stuff out in a clinical "modelling " manner made such errors more obvious. Surrounded by the actual "this and that" of recipe building and dealing with different measurements, and things get overlooked (and not just by me!). You might be told you need 50ppm (50mg/L) of Calcium ions in your mash water, but do you know when it needs to be 50ppm? Are you sticking to that "when"? ...

 

[bwible]

Speaking for me, I have a tiny electronic jewelry scale I use that was bought for me as a Christmas gift by my late wife a few years before she passed away from cancer in 2013. The scale is probably near 20 years old, it’s probably not as accurate as something I could buy new today, and it was expensive back when she bought it. I keep it obviously for sentimental reasons, I even still store it in the extra gift box it was wrapped in. It weighs to .1 gram. I make 3 gallon batches and I originally wanted it for hop measurements, but now I use it for water additions too.

I’ll say that I am not trying to replicate any water “exactly”. First, we don’t care what the water profile is in London, Munich, or anywhere else. Because you’d be a fool to think brewers there aren’t adjusting their water too. Second, you can send a sample of any water to Ward several times throughout a year and your numbers will not come back exactly the same twice. Water constantly changes. So there are no exact numbers to hit. Its all ranges. Therefore, I agree - nobody needs to measure gypsum to .001 grams. We don’t, and we don’t care. But we measure - we don’t just say “yeah, that looks like half a gram.”

Now let's talk about recipes and exact hop measurements to try to get exact IBUs - .719 oz of anything for exactly 18.6 IBU. Thats assuming the AA% on your label is exactly right, it hasn't been affected by storage, your utilization is exactly what you think it is, and you boil for an exact time to an exact second. Let alone whether your tastebuds can even distinguish 18.6 IBU from 22.9 IBU

Alot of us who do this are technical people and we all have some degree of OCD. But you just don’t carry it to excess.

 

[bwible]

No fault of Bru'n Water or anyone. Except! Whoever mentions "ppm", "mg/L", or whatever, as a value to use without providing the context to use it in.

Here's your context. Again, there are no exact numbers. It's all ranges. I struggled with some of this too,

 

[Peebee]

Here's your context. ...

Okay. It's very late at night here and I shouldn't be attempting anything concerning numbers. And I've also drank one or two beers ... so, what the hell ...

Take the first line ... "Pale Ale". The numbers haven't got units, but these water ones are usually "parts-per-million" (ppm). This example says 50-100ppm of Calcium (Ca). I reckon I'm going to go with 100ppm and my mash will be half the batch size (water used). As it happens 100 parts-per-million is five grams of calcium salts (say of CaCl2) in that quantity of water (you need some imagination to come up with that figure as there's no other clues in the data).

Hold it! Last minute change ... the mash will be too thick. Let's say we use 3/4 of the batch size of water instead. Because the water is to have 100ppm calcium I'll need to increase the calcium salt from 5g to 7.5g. Eh? ... I'm adding all this extra calcium, but the recipe hasn't otherwise changed one bit. Which is right? 5g or 7.5g?

Confused? You should be! Why the heck did we allow this cobblers to invade our lives? And this is just a minor annoyance compared to what I'm trying to pull off in earlier posts. And I haven't even mentioned "hundredths of a gram" (until now). Someone suckered us into this nonsense ... wouldn't we like to know who?

Cheers, and Good Night!

 

[bwible]

I’m not confused at all - you are.

Its really not that bad. You start off with your water numbers. Then look what you need to correct.

You enter your grain bill and mash water and sparge water amounts. Thats for YOU to decide. Most of us use 1.5 qts per pound of grain. Not a mystery.

My water has borderline high sodium. So my water is not soft. Soft water = low magnesium + low sodium. If I want soft water I have to dilute mine with distilled water. There’s a place in your program to enter the % of distilled water you use. Ie 1 gallon out of 4 = 25%, 2 out of 4 = 50%. If I’m brewing hoppy beers I can use straight tap water and not worry about diluting.

From there you adjust your sulfate and chloride levels appropriate to what you are brewing by adding gypsum to adjust calcium and sulfate and calcium chloride to adjust calcium and chloride. Its all about the balance between these 2 - sulfate and chloride. Some worry about magnesium, not me. Once you have the balance, you then add acid malt or 88% lactic acid to get your mash ph right.

In your recipes, dark malts lower mash ph. If you have no dark malts or little dark malts then you need acid to adjust the high ph down.

The levels are for you to decide. Hoppier beers = more sulfate than chloride. Lager beers and less hoppy beers = more chloride than sulfate. Some beers you balance sulfate and chloride equally.

 

[bwible]

deleted

 

[Peebee]

Hi @bwible. Okay, we're both misinterpreting what the other is going on about. So, we'll leave it at that ... for now: I reckon we can still have a decent conversation about this, but much later into it (I've no intention of bringing sulphates and chlorides into this just yet, only "alkalinity" and calcium ions).

Hang-on to using that single decimal place scales, which is more than enough accuracy. I might be giving the impression of wanting ridiculous precision, but I'm currently only "modelling", what I hope will be, a simplistic solution. However, at the moment this thread is turning into an irreversibly controversial subject!

Thanks for the data I used in my last post. It provided a much clearer example of what I'm griping about than I'd used.

 

[mac_1103]

A hundreth of a gram is overkill.

If you mean that the Brun'Water model itself is forcing you to do anything, that's silly.

In Excel you can go to "Format Cells" and "Number" and select the number of decimal places you want to display. Never tried to (or needed to) in Bru'n Water, and maybe those fields are locked, anyway.

The version of Bru'nWater that I have reports the recommended salt additions to the nearest tenth of a gram and doesn't let me change the formatting of the output cells.

The ignore button is your friend, guys.

 

[Peebee]

I guess I shouldn't have "ranted": The situation I was ranting about, mixing "concentration measurements" with "absolute measurement" ("absolute" is probably the wrong word to use **), which probably only became a noticeable issue in the last ten years or so. Once we all stuck to a rough "standard" mash thickness (about 2.4 litres water to kilo of grain, or 1.1-1.2 quarts to a pound of grain), so our "absolute" measures (pounds, Kgs, etc.) were more or less "concentrations" too? Now it's complicated by using "full-boil-length-mashes" ("BIAB" and people using "AIOs" who refuse to accept they are "all-in-ones", but are "all-in-twos" instead, the second being a "sparge water heater" and they don't want one ... me neither!)

Minor corrections for clarity ( )


On the subject of "mash thickness" ...

... The change between the two tables are the Mash thickness: ...

What was I talking about! I wasn't concerned with "mash thickness" at that point. Just ratio of mash water to "Batch Size". However, I did run up some "Mash Thickness" figures for that table (measured in litres and kgs unless stated otherwise):
.

.
I'll get those tables updated and "normalized" at a later date.




** I think it's not really "absolute" 'cos the measurements are still relative to being on the planet "Earth", but I don't really know for sure. More , or should it be ? Well, I suppose it is the "Brew Science" section, so perhaps I can get away with being a bit geeky?

 

[jdauria]

Then there's the "close enough for government work" approach of just adding a teaspoon of this and that.

Hey as a government worker, I take umbrage...oh wait, I am reading HBT at work...forget you ever saw this.

 

[MaxStout]

Hey as a government worker, I take umbrage...oh wait, I am reading HBT at work...forget you ever saw this.

I could've used this one instead.

 

[Peebee]

... were a fixed amount of CaCl2 to provide minimal Mashing needs (35ppm Ca, still under review). ...

Still under "review". But already I've seen there's a huge blunder in this ... all the ranting I've been doing and I was making the same mistake I was ranting about: Using a "concentration" (35ppm) to specify a "fixed amount". Bad me!

But. This is what I was getting worked up about as there's lots of examples of brewers using "concentrations" to specify a specific amount. It makes sense to specify a concentration with water when you could be taking of river of water, a reservoir, the water in your (and your neighbours') tap, etc. But a "concentration" does not specify a specific amount, you must also specify an amount. Bru'n Water helpfully does this for you:

"Water Volume (L)" x "Addition (gram/L)" = "Total Mineral Addition (grams)". In the example above, remember to add both "mash" and "sparge" "water volumes" together (i.e. 2 x 0.95). Ignore the "Gypsum" in the above. The numbers are very slightly different to the numbers used in the sheet because the "Addition" was actually "0.097", not 0.10, and BW rounded it up to 0.10 to display it.

 

[Peebee]

First step of "Normalization":

I've chosen the ratio of 1 volume of mash water creating 2 volumes of Batch Volume. This is the most contraversial step, 1:2 ratio, because I've decided it's the ratio used to produce all those figures like "Ca required for mash = 50-150ppm". "Ppm" is about exactly "milligrams per Litre (mg/L)" when talking of very small amounts (a few tens of "milligrams) in water. But if we want the "specific" ("absolute" <sic>) amount we must have the number of "Litres" (I'm obviously using metric rather than US Imperial). If anyone knows the actual, original, working out of those brewing water figures, I can correct the assumption I've used above.

Now as it happens, the "scheme" I'm attempting to describe is restricting the ratio of mash water to Batch Size to only two or three values; and one of those will be 1:1, or "full-boil-volume-mash" (like BIABers use). The "specific" amounts of Calcium are required because it is intended to react with a "specific" amount of grain, not water. Calcium at this stage is to be a fixed amount, because its reacting with elements in grain will push down the mash pH, we want to keep that under control, and that's the reason the "specific" volume(s) of water (containing a "specific" quantity of Calcium) has already been decided above.

Crikey! It's painful stuff this, and most likely hard to believe the finished "scheme" is intended to be really, really, simple! But I have a picture of what I'm doing in me ("brain damaged"!) head and I'm trying to get it out! "Simple" also means "simple for me to use", yet with no compromises to accuracy (so anybody can weild this water chemistry stuff like a first-class clever dick).

All of this is because my first attempt (#42 above) introduced a run-away "alkalinity" tally. This'll fix it! Now I'll take a break before straightening them numbers up, then looking at "Second Step" which is to get some reliable "alkalinity" figures (using sodium bicarbonate for tweaking).

I've also been looking at Martin Brungard's recent "Irish Stout" video ... This scheme is going to work a treat with that! When it's working! (At least I have the key motivation to get it right .. it's to assist me!).

 

[Peebee]

I've also been looking at Martin Brungard's recent "Irish Stout" video ...

Found the link!



Dated early Feb 2025. Just be aware it does include a bit of ongoing "anti-European (... Brit!)" hostility. Here! I'm a Brit ... okay, counter-swipe time: There was no "Irish Dry Stout" before about 1920s. "Black Malt" wasn't invented until 1817 (before that they had accidental bonfires!). Roast Barley was illegal in British beer before late 19th Century (Ireland was still subject to English occupation and English law at that time). But I believe they had dropped using "Brown Malt" in their "Stouts" by then? "Stout" was considerably stronger than today's (OG probably at least 1.070), Guiness "Stout" was more likely "Porter" back then.

Don't get sucked into the (still ongoing) "Guinness mythology-building (marketing) machine" (which I don't think Guinness actively organise ... their drinking public just do it for them!). The rest of Martin's video is great though