Pretzel logic

Final lab session of our Food Chemistry class this year.

20100311 AR pretzel ANNOT

An experience of the effects of pH on browning reactions.

We make a variant of traditional soft pretzels, using a rather leaner formula than often used [for us no milk or eggs]. The loss of lactose from the milk and glucose from the egg might have contributed to our failure to get the same level of color development we saw last year when we used a full rich formula with egg and milk.

20090312 pretzels

Still it is a great way to experience the effect of pH shift on the color and aroma generated by primarily Maillard browning, allthough at pH 14 in the 4% NaOH, other reactions are very likely.

2010 formulation


2009 formulation

untitled 2009

A poolish is a 50:50 mixture of flour and water BY WEIGHT with about 0.1% of the flour weight as dried [instant] yeast [NO SALT] that is allowed to ferment around 16 hours before being added to the final dough.

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.

Interesting post from Khymos – and some other things


Martin Lersch has a post (Dangerous names)  inspired by an article entitled  “If It’s Difficult to Pronounce, It Must Be Risky” by Hyunjin Song and Norbert Schwarz of the University of Michigan and published in Psychological Science


So… you think there’s nothin’ obviously dangerous sounding in the ciabatta pictured below ? – think again –

It has 80 baker’s % DHMO

and it has a fair splash of durum flour, which is enriched in 1,3,3-trimethyl-2-[(1E,3E,5E,7E,9E,11E, 13E,15E,17E)-3,7,12,16-tetramethyl-18-(2, 6,6-trimethyl-1-cyclohexenyl)-octadeca-1,3,5,7,9,11,13,15,17-nonaenyl]cyclohexene

This chemical gives the bread a nice yellow color and seems to carry more flavor as do some other non-polar triacylglycerol-soluble molecules.


(recipe adapted from “Bread Baking: An Artisan’s Perspective” by Daniel T. DiMuzio)

BUT – if you like your chemicals silly and have a open-minded sense of humor then this is the site for you: authored by Paul May of the Bristol University School of Chemistry