Pottery Making at the Bradford Kaims – Videos

This blog presents the video interviews from our open archaeology day which focused on prehistoric pottery.

The first shows Rachel Brewer, Assistant Supervisor, discussing the process she went through – first to prepare the clay and then to produce fired ceramics. The second presents some thoughts about the day from two of our students, Ewan and Ian.

 

Thank you for watching!

Stay tuned for more of our experimental sessions – coming soon!

Experimental Prehistoric Pottery

This week’s experimental blog is courtesy of Rachel Brewer, Bradford Kaims Assistant Supervisor.

 

Following on the heels of the beer brewing experiment, our Week 5 experimental archaeology project was an effort to make a variety of pottery vessels using only raw clay sourced from our prehistoric site here at the Bradford Kaims. We knew from previous seasons that the trenches and test pits often turn up natural clay deposits of varying colours and quality. We’ve also had a few examples of possible Neolithic and Bronze Age potsherds surface during excavation; so this summer’s experimental archaeology program seemed like a perfect opportunity to test out our prehistoric potting skills! Altogether, processing the clay, forming the pots, and the subsequent firing turned out to be a messy, fun and educational experiment for all involved.

 

Step 1: Gathering the clay

While digging a series of shovel test pits earlier in the season, we hit upon a substantial deposit of clay about 50cm below topsoil. Seeing a source of raw material for our pottery experiment, I dug out a bucket’s worth to begin processing. Though the clay was mostly light orangey-brown, there was a thin layer of grey overlaying that; it also gathered a good amount of silt and peat on its way out of our 20cmX20cm shovel test pit. Through processing, these colours and textures blended together as shown in the later photos.

 

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The raw clay.

 

Step 2: Processing the clay

This was the longest part of the process, due in part to my own inexperience and also to the wet conditions on site. I knew from research that the best way to process raw clay is often to dry it out completely, grind to a powder, sieve, and slowly reintroduce water until the clay reaches a workable consistency. I also knew how unlikely it would be that we could completely dry out that amount of clay in a timely manner, particularly when it was raining almost daily. So I opted instead for wet processing, which involved the help of several pairs of hands pulling all of the clay into small lumps and mixing/mashing it up with added water in a large plastic box. This part worked better than expected, and after a couple of days of minimal stirring, nearly all of the clay was liquefied.

 

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Slaking the clay on site.

 

At this point we poured the slip (liquid clay) through a sieve to remove the largest inclusions, mostly small stones and twigs. We could have used smaller screens and sieved multiple times for greater purity, but I chose not to since examples of prehistoric pottery found at this and other sites indicate that prehistoric people were not processing their clay to a high degree.

 

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Sieving the slip.

 

For about a week I attempted to do a daily pouring-off of the water that would accumulate on the surface, hoping that between evaporation and pouring off that the clay would thicken a bit every day. The couple of days I was able to let the boxes sit out in the sun did help, but it wasn’t working quickly.

 

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The slowly thickening slip.

 

On one sunny day I cut open a bin liner and laid it out on the grass like a small tarp, then I poured the thickened slip out on the plastic. This increased the surface area the sun could reach and it was noticeably thicker by the end of the work day, but it still wasn’t drying out fast enough. We had to rearrange the experimental schedule and move pottery back a week – I had only a week to get some workable clay and I was running out of ideas!

 

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Spreading out the clay to increase the surface area for evaporation.

 

My final effort involved pouring the clay into an old pillowcase, tying it closed with string and hanging it from a tree to allow the water to drain out with gravity and air. The better part of the week passed before I noticed much of a change, but much to my relief, the night before we were scheduled to make the pots we had somewhat sticky but relatively workable clay!

 

 

Step 3: Forming the pots

Before beginning our pot making, the students used rocks to crush up a few soft pieces of sandstone sourced from Trench 6; we used this sand as temper.

 

 

Since wheels were not used by prehistoric potters, the students learned to use the two most common methods of building pottery without a wheel: the pinch method (formed by pinching a solid ball of clay into the desired shape) and the coiling method (rolling out rings of clay, stacking the rings, and smoothing them together). A small amount of temper was added by each individual to their own allotment of clay. Of course we had some creative minds in the mix who ventured beyond the utilitarian forms like bowls and jars, and by the end of the day we had quite a collection of unique creations! We set everything we made on two log disks that would be easily moveable and would absorb moisture. After that we just had to let everything dry out completely to prepare them for firing.

 

 

Step 4: Firing

When it was time for firing, we began by building a small fire in our fire pit on site. Pottery has to be heated very slowly, so we began by placing the dried pots around the edge of the pit and then slowly moving them in close to the fire. Once the pieces were against the central fire, we began placing larger branches over and around the pots, completely covering them and creating a kiln effect. We kept a large fire burning for about an hour and a half, then allowed it to die down to coals. Since our time on site was limited to 5 hours and the pots needed to be cooling before we left site, we weren’t able to keep the pots firing for the ideal amount of time, which for our purposes would have been around 4 hours.

 

The final step of firing is allowing the pots to completely cool before removing them from the pit. Before we left site for the day, we dug the pots (none of which had broken!) out of the coals, stacking them against one wall of the fire pit and shoveling the coals to the opposite wall. We then covered the pots with a layer of grasses and sedge, placed a couple of metal sheets over the pit to protect the pots from rain, then left for the night.

 

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The fired ceramics hot from the fire.

 

Upon examining the cooled pottery the next day, I was pleased to see that none of the vessels had cracked or exploded during firing. Additionally, the pieces had fired, if not completely through, then most of the way through despite the shortened firing time. The fired pots are noticeably brittle and not completely water tight, but with a little more practice we could probably produce vessels that would be more serviceable. Since we accomplished our goal of using only raw materials from site and a fire to create prehistory-inspired pottery – and we had fun doing it – I’m calling this experiment a success!

 

Experimental Brewing Summary and Student Reflections

In a follow-up to our earlier blog on prehistoric brewing, these videos record a summary of the process from Becky Brummet, Experimental Programme Director:

As well as comments and reactions from two of our students who were there on the day:

Experimental Beer Brewing

We began last week’s experimental day by gathering ingredients, trying to use as many prehistoric resources as possible. Though some tools were still modern (the trough, matches to start the fire, chainsaw to cut firewood, a mesh sieve, and a pot) we used a variety of other resources during the day including:

-Un-malted Barley (already acquired from a local source)

-Rocks for the fire (from the T6 spoil heap)

 

Julie collecting stones

Student Julie gathering stones for firing,

 

-Water & a trough (modern trough, sourced from local farmer, James Brown)

-Elderflowers (gathered from site), and

 

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Assistant Supervisor Charlie, gathering elderflowers.

 

-Firewood (fallen deadwood gathered on site)

 

And after talking through the process, we began the beer brewing!

 

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Super visor Becky, teaching students and volunteers.

 

We started the fire, and heated the rocks for about one hour.

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Fire Starting

 

During that time, we broke the husks of the barley to release the yeast. There was an added level of experimentation in that our barley was un-malted. We’ve had some success with this in the past, and were attempting to replicate those successes in order to test several hypotheses we had developed.

Julie and Ian grinding barley

Students Ian and Julie breaking the barley husks.

 

Grinding barley action shot

Close-up of the grinding process.

 

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The barley after the husks were broken.

 

When the rocks were hot enough (we didn’t verify an exact temperature, just made sure they sat in the fire for an hour), we added water to the trough, added the barley to the water, then added the rocks to the water to heat it up.

 

 

We needed about 7-8 rocks to get a warm temperature. We did not measure the exact temperature, rather we made sure it didn’t get too hot to the touch.

We stirred the mash, and rotated hot rocks in and out of the trough to keep the temperature up.

 

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Supervisor Becky stirring the mash tun.

 

We had lots of down time while we kept the fire going, kept the rocks hot and the mash tun up to temperature, so we gathered local sedge (tusset grass) & began weaving platters & baskets – a skill we recently learned from a local community member, Paula Constantine who teaches basket weaving.

 

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Assistant Supervisors Rachel, Sophie and Charlie weaving sedge.

 

We also took some malted barley (leftover on site from previous beer brewing attempts) and sedge oil (created from pounding sedge root into a pulp and adding water), and created a paste which we then put on the fire to bake. We experimented with an different cooking technique than our earth oven from last year.

 

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Unleavened bread baking above a fire.

 

After the mash tun brewed for two hours, we began to sieve the mixture into our pot:

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Students Julie and Zac sieving the mash into a pot.

 

And then we added the elderflowers to the mixture.

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Students Zach, Ian and Julie adding elderflowers to the mix.

 

We’ll let the mixture brew while we continually monitor the progress throughout the week.

Next Sunday, we’ll check the ABV level with a hydrometer & let it brew for longer if need be (two weeks or so should be sufficient).

We usually can get an ABV level of 5%, so that’s our goal. If we’ve reached it by next Sunday, we’ll sample it, if not, it’ll brew longer.

Stay tuned for next week’s experimental instalment!

 

Bradford Kaims Experimental Archaeology Schedule

Come and see experimental archaeology in action!

Hot rocks

Hot rocks used to heat water and malted barley as part of the brewing process.

 

19th June – Prehistoric Beer Brewing

Learn the process of prehistoric beer brewing!

26th June – Prehistoric Pottery

Using local materials procured from ongoing excavations, we will attempt to make small pottery pieces!

3rd July – Beer Decanting/TBA

If the beer has fermented sufficiently, we’ll be decanting our brew and testing the ABV (and sampling it!)! If the beer isn’t ready there may be a day of flint knapping.

10th July – Flint Knapping

Learn the basics of creating stone tools (like those discovered on-site) using flint and obsidian.

17th July – Woodworking

Learn the basics of rudimentary woodworking.

24th July – Resin Production/Hafting

We hope to create resin and use it to haft tools that we’ve made during the season.

**Activities are subject to change depending on weather conditions & ability to procure materials and/or resources**

We welcome local volunteers and community members, but for logistic purposes, please let us know ahead of time if you wish to drop by!

 

Becky Brummet

Experimental Programme Director

Email: ruthefordr22@yahoo.com

BRP Office Phone: 01668214897

SAMSUNG

Flint blade found in Trench 6.

 

Experimental Archaeology – TIMBER!

At the Bradford Kaims we have been branching (sorry…) out into woodworking as a part of our Experimental Archaeology Programme. Similar to our brewing experiments where we have used hot-rocks due to evidence from the burnt mounds, we decided to try some woodworking due to the exceptional preservation of wooden material at the site. To assist us we had the help of local woodcarver Dave Robson, who kindly supplied us with several sycamore logs and rowan branches and to offer guidance in woodcraft. As well as utilising local specialists, we had community volunteers Barbara and Tim partaking in the experiments along with our students.

For our initial investigations, we have been looking into splitting wood (inspired by our potential Neolithic plank in T10!) to see how easy/difficult the process would have been only utilising resources available before metal working. To split a modern log a woodcarver might begin by creating a notch along the diameter of a log with a steel axe or froe before driving wooden or even steel wedges into this notch to prize the wood apart. Rather than using an axe however, we attempted to use bone “chisels” which we had created ourselves (by smashing the bones and subsequently grinding them on a piece of sandstone to create an edge.)

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Our prehistoric bone “chisels” ready for action!

With the bone chisels ready, we used them in place of the axe, creating a groove across the diameter (through the central “pith” – the weakest part of the log) by holding the chisel in place and subsequently hitting it with a wooden mallet. Once our groove was created, we hammered oak wedges into the groove and proceeded to drive them into the wood with the mallet, trying to keep the wedges at an equal depth by hitting them alternately. Within minutes, the logs would make audible groans and cracks, before splitting apart down their length! We found that for the sycamore logs which we were using (admittedly not present in Britain until the middle ages so not found in our trenches) the bone chisels worked incredibly well for initialising the splitting, from there the wedge process was the same as it would be for modern log splitting. We were able to demonstrate that log splitting can certainly be achieved with little difficulty with prehistoric resources – though of course whether this was the manner for splitting logs prior to metal tools we are unable to know for certain.

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Student Tom and community volunteer Barabara planking a split log

With logs split down the diameter, we moved onto further splitting in an attempt to plank our now halved logs. This came with mixed success, while splitting would go well initially on several occasions the split would shear off due to knots lower down the log. One of our best efforts came from students Tom and Sammi, who managed to split off a plank with minor shearing from the mid-way point. To flatten the plank, we used a flint axe provided by Dave Robson which allowed us to gradually create a flatter surface. Rather than cutting into the wood like a modern steel axe, the flint axe tended to shear off and tear the wood creating a rough surface. In order to smooth this, we used our polished bone chisels and knives like a modern plane to take off smaller chips of wood which made a surprisingly smooth surface!

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One plank ready for further working

An enjoyable day was had by all of our participants, with students and volunteers alike surprised at how easily we were able to split the logs using little more than bone and wood! With our planks of sycamore we are hoping to continue our experiments further this week by trying to replicate artefacts found in our wooden platform again only using prehistoric tools!

Experimental Archaeology – Good food and good drink.

Over the last few weeks at the Bradford Kaims we have been continuing our brewing experiments. Our first two batches, from week 2, were left in the hedge line following the removal of the barley and the addition of hawthorn flowers. Initially very little activity took place after a week in the hedgerow, but once placed in a warmer environment (one of our caravan awnings) fermentation began! Within a few days our first batch reached an alcohol percentage of 5% and our secondary batch reached 3%!

“Successful batch – didn't taste bad either!”

“Successful batch – didn’t taste bad either!”

Since then we have attempted another batch, which following the mashing stage we sieved out the barley and separated it into two containers, one with heather and one with elderflower. The two different flower types were selected as different sources of natural yeast to see if that had an impact on the fermentation process but also to see the difference in taste! Unfortunately, following the mashing with our hydrometer we found a very low potential alcohol content. This could be due to a series of reasons such as the barley husks not being crushed enough or our barley to water ratio being too low. Despite this our students and community volunteers were able to engage themselves in the mashing process by making the fire, breaking barley husks and heating water with hot stones – which can be quite the spectacle when submerged in the water. As a result learning has still taken place (and plenty of enjoyment) through the production process. We can also take our observations forward to inform our future brewing ventures, which we will be continuing in future blog updates!

“Elderflower and heather being used as natural yeast.”

“Elderflower and heather being used as natural yeast.”

Following on from last week’s brewing, we have been cooking in addition to brewing using hot-rocks. We set our fire lined with rocks, as we have done for brewing. We built the fire up to heat the hot rocks but then let the fire down to ash. While still hot we laid down a lattice of reeds over half the fire pit with a variety of root vegetables laid on top (carrots, sweet potatoes, garlic cloves and onions), while we left the other half open to place our vegetables to be wrapped in reeds directly and placed in the pit. With the food in place we covered it all in another lattice work of reeds and subsequently buried the food to retain the heat of the hot rocks. Now to wait!

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“The earthen oven under construction.”

After two hours we carefully opened up the earthen oven to reveal our cooked food. Due to a delay in burying the food (we did some brewing beforehand which allowed the fire to cool) most of the vegetables were partially cooked. However, one onion in particular was cooked right through after being placed in a particularly hot area of the pit – evident from the burnt reeds it rested on. Staff, students and community volunteers alike gathered around for the unveiling at the end of busy day at the site. We all tucked in for the warm food to taste how easy it was to make an oven which required no maintenance when in use.

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“Opening up the earthen oven!”

For the cooking, we decided to have a fire burning with other processes taking place nearby (such as flint knapping) as in prehistory it seems unlikely that a day would have been dedicated to a single activity like we have been doing. Various activities would have taken place side by side with different members of the group undertaking different processes (potentially). To that end we will strive to have several activities taking place during our “Experimental Days” to more accurately represent how activities and processes may have taken place in the past.

“Hungry archaeologists!”

“Hungry archaeologists!”

Experimental Brewing at the Kaims

This week at the Bradford Kaims we have begun our new Experimental Archaeology Programme! Experimental archaeology is the process of recreating past technologies utilising resources which would have been available to societies in the past. Through this process we can gain possible insights into the mind-set of people in the past as well as insights into the processes they underwent in the creation of the archaeological record.

Our initial investigations have been in brewing our own beer. Due to the wealth of fire-cracked stones within our burnt mounds, it is likely that the occupants of the site were heating water. Similar to how we use hot water today, there is a large variety of possible uses; cooking, cleaning and sweat lodges. Due to the heating process required in the production of beer, brewing could have been a possible activity taking place at the Bradford Kaims.

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Becky and Miranda grinding barley with a variety of tools

Our methods were simple:
· Mashing/grinding malted barley
· Creating a firepit to heat the stones
· Add the ground barley to water
· Add hot stones to get water up to temperature for two hours
· Sieve the heated mixture
· Add flowers for flavour (in this case hawthorn) and a small piece of bread for yeast
· Sit covered for 4-5 days for fermentation to take place

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Hot rocks being added to the barley and water

Currently what we did has not necessarily been experimental archaeology as there was no true “experiment” taking place – there were no variables being tested or research questions being investigated. The value in this initial process is that we are learning about the process and gathering potential areas for further investigation.  We will be doing more brewing over the season, along with some more experimental archaeology focussing on flint knapping and prehistoric wood working (to create tools to tie onto our brewing experiments). Hopefully by the end of the season we can link our experiments together to add to our interpretations of the use of the Bradford Kaims site… plus – experimental archaeology is pretty fun!

Experimental composite tool making

Director Paul Gething did a bit of experimental archaeology this past weekend. Here’s what he has to report.

I did a little experiment to see how quick and easy it would be to make a composite tool. The idea was to make something that could be used to harvest sedge at the Kaims in the summer. I attempted to make something between a saw and a sickle.

I took a few flint flakes that I had as debitage and just general surplus from my patio floor.

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I found a length of willow from my woodpile and a larger flint to work with.

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I used the retouched saw edge to cut the wood to size. I scored a deep groove all the way around and then snapped the wood cleanly. The wood is 25mm diameter and was harvested in the autumn of 2014. Sawing a 3mm groove all the way around took under 2 minutes.

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I used a hooked flake to cut a groove in the willow. Once it was started it was very quick, only taking ten minutes to cut a groove 5 mm deep. (The actual flint used was the hooked flint in the top of the glued final piece photo).

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The final step was to glue in the flint debitage I had scrounged up earlier.

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The glue was some I had lying around from my other projects. It was made a while ago using wood ash, warm milk and vinegar.

The entire build took 35 minutes. If I had used resin or similar and therefore needed to heat it up, I imagine that would have stretched to 45 minutes.

I will take the finished tool to the Kaims in the summer and see how it performs. I will report back in June.

PAG