A day at the office…

My job as a cereal scientist sometimes affords me the joy of a full day of baking, product development, and promotion of our work and the farmers who are putting their money where their mouth is and growing food barley.

In all the products shown below, the flour has a minimum of 10% stone-ground whole barley. The long loaves and the pretzels have 50% wholegrain barley flour and the big sandwich loaves have 50% barley with 35% stone-ground whole-wheat. The remainder is plain baker’s flour.

This was for our successful  “Barley and Friends” field day. {link} held this May 9th.

And good practice for our event at the “Kneading Conference West” in September {link}.

The barley pretzels are, of course, the natural accompaniment to that other barley product, good beer!

Thanks to Jake Mattson of the Oregon State Food Science department for helping to divide, shape, and dip [in 1M NaOH] the 100 pretzels we made!

More whole grains at Oregon State

I’ve been having a work “vacation” – working with Craig Ponsford at the “Ponsford’s Place”  Innovation Center [link] to fine-tune our barley bread formulations.

We uncovered some interesting processing challenges that point to the particle size of the barley flour as being a suspect.

We played with the water because barley has so much great soluble fiber as mixed linkage beta 1-3, 1-4 glucans that it soaks up water like a sponge. These breads had 50% by flour weight whole-milled barley flour and respectively left to right 90% or 100% [flour basis] water. 100% water on this basis is equal weights of flour and water, and still it made bread.

Oregon State University’s “Streaker” hull-less barley going into the mill.

Teapots, fluid dynamics, and baked potatoes – but what are we to do with the buttery taste?

Beating the teapot effect

(Submitted on 17 Oct 2009)

Cyrill Duez’s team show that superhydrophobic surfaces stop the tea from wetting the inner surface of the spout and pretty much stop the dripping.

Richard Alleyne, science correspondent for the UK Telegraph newspaper, says this backs up the old adage that putting butter inside the spout stops the drip.

But no-one is saying what we should do with the buttery taste – maybe get used to it like the Tibetans have with tsampa (toasted barley flour, green tea, and yak butter) – see picture on the last page of the linked PDF file

Of course all this leads to some interesting side trips on the internet, this time to the web page of Lydéric Bocquet an the Liquids @ interfaces’ group at the Laboratoire de Physique de la Matière Condensée et Nanostructures, Université Lyon 1, and a link to a paper of his from The American Journal of Physics from 2007 called “Tasting edge effects“. The paper  backs a hypothesis that, to quote him, “the baking of potato wedges constitutes a crunchy example of edge effects” .  He goes on to say in the abstract- “A simple model of the diffusive transport of water vapor around the potato wedges shows that the water vapor flux diverges at the sharp edges… This increased evaporation at the edges leads to the crispy taste of these parts of the potatoes“.

All I can say is, thank goodness this happens and that baked potatoes have extra tasty edges, all a function of increased drying rates that speed Maillard browning.

FotoosVanRobin via Flickr

Coffee stains explained

And an hour later  – even more interesting things – like the paper 12 years ago in “Nature” that explained the nature [pardon the unintentional but awful pun]  of the rings in coffee stains via a flow from the interior of the liquid to the exterior, bringing suspended material with the flow and depositing it at the edge of the drying droplet. And coffee is a good example because oft he amount of dispersed but not dissolved material in the cup. It would be interesting to see if the effect is more pronounced with espresso than drip filter given the far higher level of suspended solids in an espresso cup.

Capillary flow as the cause of ring stains from dried liquid drops”  Robert D. Deegan et al

Nature 389, 827-829 (23 October 1997) | doi:10.1038/39827 – even folks without a full text subscription should be able to access the abstract via this link .

Who’da thought Nature would be interested in coffee stains – still,  the journos and editors, they probably live on coffee.

Why does my pita puff ?

Pita is made from one layer of dough, not as some think 2 layers that are joined at the edges.

So how does if puff?

The dough is often given a final proof that is drier than for risen breads. When the bread hits the hot oven the slightly dry skin seals. Really thin flat breads like pita can be baked at extreme temperatures. My lab in Sydney when I worked there used a pottery kiln for our routine test-baking of pita, and we baked them for 30 seconds at 550 degrees CELCIUS (about 1020 degrees F). Not unlike the conditions in a tandoori oven.

The sealed skin first constrains the existing gases in the small amount of dough that will turn to crumb. These expand and exert more pressure in line with the gas laws. There MAY be a VERY brief moment of additional carbon dioxide production from yeast but this will be really limited in the thinner types. But the greatest gas production and pressure comes from the water in the dough that turns to steam, lots of gas an pressure now. If you see the video in my last post you’ll see the outcome. The interior splits at the weakest point creating the taste sensation of fresh, high temperature baked pita bread. Good enough to eat on its own.

You can access a schematic of this on the google books preview of Jalal Qarooni’s Flatbread Technology book (page 71).

And why does my poolish lose weight ?

I commonly bake using a yeast poolish, a mixture of equal weights of flour and water, and a vanishingly small amount of instant yeast that is allowed to ferment overnight or longer. This long pre-ferment creates bread of outstanding flavor.

Anyway, I am, as many bakers are, in the habit of scaling out the exact amount of poolish I will need for a dough (I always bake using formulations that list ingredients by weight).In the morning i use the poolish assuming the same weight. Duh !! Some chemist I am.

Out of error the other day I had more poolish than I needed. When I weighed what I had I had 952 g. The evening before we had scaled out 500 g flour, 500 g water, and 1.5 g yeast (1001.5 g). It is clear that we’d lost in the order of 5% of the poolish weight. As I had covered the poolish I assumed this was not water loss, but loss of carbon dioxide (and maybe volatilized ethanol). Poolishes rise but at 100% hydration they are pretty weak and sloppy and gas loss would be expected.

If this was the case the weight loss would come from the conversion of starch to maltose , and the conversion of the maltose, via the fermentation pathway to CO2 and ethanol with the subsequent loss of volatiles. Anyway the result is a poolish that is more than 100% hydration (1.11 %) as the substrate comes mostly from the dry solids part of the poolish (although maltose requires the addition of 1 water molecule when hydrolysed to 2 glucose). This probably isn’t enough difference to cause dough handling problems and I can just go back to my weigh out the poolish the night before assumptions and not worry about it (until I do any poolish research, with the aim of eating the experimental outcomes of course.)


barbari bread got me thinking…

Been trying a new bread style this week, as well as using a non-traditional grain in a familiar type of bread.

The non-traditional grain was a pita bread made with 50% stone ground barley and 50% stone ground hard white wheat. These were astoundingly successful and the barley adds a unique and attractive character to the flavor. Real simple, the flours (100% – baker’s percents), plain yoghurt (50%), salt 2%, instant yeast 1%, water (62% – it was this high because of all the water-absorbing capability of the beta-glucan fiber in the barley). 1.5 hours bulk fermentation, round into 80 g balls, rest 20 minutes roll out to about 15 cm disks about 2 mm thick, “proof” 20 min at room temperature, they were baked at 275 deg C (about 525 F) as hot as my oven can go for about 2.5 min. Eaten fresh thet wer close to the best thing since… well much better than sliced bread.


This was the fun one…

Pictured is my second attempt at making an authentic version of an Iranian flat bread called “barbari”. I had heard that it could be formulated with soft wheat, hence our interest here with our soft wheat breeding program. But it had a few interesting twists that led me to some interesting food chemistry. An Iranian colleague that lives in the USA validated it as authentic – so here we go.


I used a formulation and process gleaned from a number of sources including books by former colleagues Ken Quail at BRI Australia in Sydney, and Jalal Qarooni.  The interesting twist is the use of baking soda (sodium bicarbonate NaHCO3)  in both the dough and the starch-based glaze. This is called according to Qarooni – roomal – a 10% paste of flour and water cooled to room temperature – we also added enough sodium bicarbonate to make a 0.5% w/v solution with a pH of 8.2 even with the buffering capacity of the flour.

The formulation was…

High extraction flour milled from soft white,  100%, water 65%, salt 1.5%, sodium bicarbonate 0.35%, instant yeast 1%. This was mixed to full development (“intensive mix”) and allowed to bulk ferment for 2 hours. The dough pH was 6.8 – even with the bicarb (a greater than 0.5% w/v solution in the dough’s aqueous phase – it’s not exact as we need to consider the absorption of the flour components) – the buffering capacity of the flour was more than enough to compenstate for the bicarb.

The very slack dough was divided into fairly substantial 800-900 g pieces and preshaped and rested 20 minutes and then stretched into the traditional oblong shape. This was rested on the oven peel and the roomal was applied along the docking with the fingers (the long channels in the bread that stop it puffing up like pita) and with some sesame seeds. The whole shebang was baked at 230 deg C (about 450 deg F) for 10 minutes.

Apart from the usual marvelous transformation from dough to bread, there was another at first puzzling transformation. We expected the crust with the alkaline roomal to become yellowish due to the alkaline de-glycosylation of the apigenin-C-glycosides allowing these flavone pigments to express their yellow color – we see this all the time when we make alkaline noodles, a.k.a. yellow alkaline noodles, a category of noodles familiar all through eastern Asia (Cantonese, Hokkien, Ramen [traditional, and even a little alkali (kansui) in the fried types], Bamee, Ja Ja Myung etc). The yellow color is additive to the creaminess imparted by the carotenoid pigments  (luteins) in the flour.


So we were surprised to see the interior bread crumb turn out yellow (the dough wasn’t yellow as it’s pH was still on the acidic side of neutral) and it tasted reminiscent of the type of Cantonese noodle favored in Kuala Lumpur that are made with sodium carbonate (Na2CO3). We measured to pH of the crumb – behold, it was 8.2 ? What was going on here. Turns out the bicarb is thermally converted to the carbonate with the release of water and some additional CO2 – hence the pH and color change of the dough/crumb during the baking process.

Finally some shameless self-promotion.

I got my author’s copy today of the new wheat book “Wheat Science and Trade” edited by my friend and colleague Dr Brett Carver at Oklahoma State U. My chapter, with Art Bettge of the USDA Western Wheat Quality Lab, is Chapter 20 – Passing the test on wheat end-use quality.