hist-brewing: ancient ale

Daniel Butler-Ehle dwbutler at mtu.edu
Fri Mar 5 21:20:16 PST 2010

(oops. . .I meant to send this to the list the other day, 
but accidentally replied to sender)

John P. Looney <valen at tuatha.org> writes:
> There seems to be a few debates around finding some sort
> of 'organic' container to hold the beer.

Nah, containers to *hold* beer is easy (unless, of course,
you're talking about a *lot* of beer).  Containers to
*store* beer is far more difficult.  And vessels in which
to convert mash or boil wort are other matters altogether.
(Oops, that last point is non sequitor. Boiling wort is of
rather recent invention; you'll find that even hard-core
paleolithic beer theorists generally don't claim that
boiling wort was commonly practiced prior to the late
Middle Ages.)

> I think a fulacht fiadh<http://en.wikipedia.org/wiki/Fulacht_fiadh>
> does seem to be a decent option;

Ah! That's what it's called!  I've read about them before,
but couldn't remember the name.  It's apparent that the
constructions were likely for heating up liquid by dropping
in hot rocks from the fire.  (A conceivably liquid-tight
open wooden vessel with some large, charred stones in it.)

The article describes a few possible functions:

1) Bath or steam bath - My guess is more like a sauna
than a steam bath. (Yes, they can be heated by dropping
hot rocks into water--it is a traditional backwoods sauna
method in Finland, and I've done it a few times myself.
Much more pleasant than a smokey sweat lodge.)

2) Cooking - Poaching meats over boiling water or
braising/stewing them in it, or perhaps just burying the
food with hot rocks to allow it to slow-cook like a
luau-style pig roast. (Actually, burying it with hot rocks
seems unlikely to me, as one could achieve the same results
with much greater fuel efficiency and ease by just burying
the food with a bed of hot coals.)

The article mentions that opponents to the cooking theory
point out that no food residues have been found on the

3) Dying - Makes a lot of sense to me, as I believe that
most natural dyes work much better at higher temperatures.
I'm not surprised if dyes don't leave tell-tale residues,
but what about the mordants?  The article also mentions
the possibility of tanning leather.

4) Brewing - They mention an experiment using a trough
and hot rocks for mashing. After mashing, the experimenters
scooped it into fermenters (apparently husks and all).  
Now, I would think that someone looking for food residue on
the rocks would have also noticed whether there was any
beerstone present.

Of course, those are all speculative.  The actual
function may have been any one, several, or none of

> wooden trough, stone lined to keep the wood under pressure
> and stop any unwanted leaks.

That part I'm not so sure of. Do you have a reference?

> As I mentioned in my original mail when heating rocks to
> heat the water - go for volcanic rocks, rather than sedimentary,
> or they'll explode/turn to lime.

Volcanic in the sense of igneous; don't use porous "lava rock".
I've used chalcedony (I had some big chunks of smooth jasper).
I recall that the Rauchenfels brewery in the Franconia region
of Germany (which, a couple decade ago anyway, was the only
commercial producer of a traditional Steinbier, in which
white-hot stones are added to the kettle to boil the wort)
uses porphyry stone.

> I've a few concerns...how do you know you have the right
> temperature, in a prehistoric setting? At a guess, I'd say
> "When the water his too hot to put your hand in for more than
> 2 seconds",

For the mash, that's about right.  Brewsters each developed
their own rules of thumb, and being able to determine the
right temperature and time consistently was their special
talent.  For mash water (before "doughing in"), I've heard
that it's just hot enough when you can no longer drag your
finger across the surface of the water twice.  

Of course, there are a lot of variables that will affect that.
If you want to try it yourself, I suppose you could either do
it the old-fashioned way of making thousands of batches to
develop a feel for what works best, or you could just decide
on your target temperatures and use a thermometer to calibrate
your finger.

> If you'd an open pit of barley in a pit - would you likely
> get animals or insects investigating ?

Aren't you running the liquid off into something else
after the few hours it takes to do the mash?  Or are
you leaving it there to ferment on the husks?

> Could these pits
> originally have had a hazel+hide covering over them ?

Would make sense if they served as fermenters (which
I kinda doubt).  But, even for mashing, having a
cover (or hood of withee wicker and hides) to limit
evaporative cooling would indeed be helpful.

> Are there areas that these would have worked better ?

For mashing?  I guess you want it near your water
source and near your firewood (don't want to be
hauling any of that up a mountain).  And consider
how (or if) you're going to strain out the husks.
(I've made and used a primitive lauter tun that
is a wooden trough containing washed straw atop
crisscrossing layers of twigs above a drain hole
at one end--works okay, but I should really get
some more experience with it.)

For fermenting?  I have no suggestions other than to
avoid sites that are too damp, too dry, too windy,
too cool, too warm, sunny, or prone to temperature
swings. I'd say it's generally the case that primitive
beers were dispensed right from the fermenter (er, not
that it was the drinking vessel, but that it doubled
as the serving vessel).  Thus, the location of the
fermenter also affected where the beer would be

> Where do you get wild yeasts that will ferment beer better

In the small towns of the Flemish countryside, of course.

Using the fermenter regularly will generally encourage
beer-friendly yeasts (and, unfortunately, beer-unfriendly
bacteria) to develop in and around it.  Just takes time.

Alternatively, one could leave some of the dregs from
the previous batch behind when adding fresh wort to the
fermenter or set a portion of finished beer aside before
cleaning out the fermenter and then add it to the fresh

> Near fruit trees ?

If there's ripe fruit around, it might tend toward
vinegar as the fruit flies will love to taste your
malt and leave you acetobacter as payment.

> Would they have built a put, gotten a crappy yeast/bacteria
> mix, and decided "screw that, we aren't using that pit again!".

Surely.  You don't continue with a site that has been a
source of ill-luck.

> The reason I'm asking is that I'd love to try make a beer
> in this way.

I'm not entirely sure what you're suggesting doing:
*Mashing in a rock-heated trough (as suggested by the Wiki
article you referenced),
*Boiling the wort in a rock-heated trough (as with the
steinbier I mentioned above),
*Fermenting beer in a trough (you don't need heat rocks
for that).

> But I think the yeasts are the real stickler.

At first, yeah.

> Could I even prep an area in advance...by scattering malted
> barley in an area for a few weeks ?

I think that would rather efficiently encourage lactobacillus,
which you probably don't want.  You might try mixing up a batch
of wort (extract if you're in a hurry; all-grain if you're stingy)
and set it out to ferment openly there (cover it once it comes
to life).  Just see what you get.  Then maybe repeat it a few
times to build up the local bru-ju.

If the resultant beer is acceptable, maybe thinly spread some
of the dregs around to increase the local concentration before
starting your trough beer (that's just an idea, not a real
recommendation; I could see it backfiring by providing an
incubation medium for beer spoilage organisms).

Do some trials with each of the individual components of your
planned trough beer procedure before putting them all together
or you'll never be able to figure out what went wrong.

Dan Butler-Ehle

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