Black bean burger patties, egg + psyllium version

The results of my little experiment described in the previous post into the properties of psyllium mucilage didn't inspire confidence. At no time was a firm gel produced, only an elastic but very soft and easily deformed mass. That didn't seem to promise much use for psyllium in making a vegetarian burger patty that would hold together better than in the first two attempts (here and here). But my search for recipes online turned up this interesting vegan burger receipt (off the FatFree Vegan Kitchen blog), using lentils rather than beans and--crucially--a teaspoonful of chia seeds soaked in water and then added to the mixture.

The outer parts of the chia seed, as with psyllium and many other seeds, contains a polysaccharide that swells many times its volume in water to form a gel-like, mucilaginous dispersion. If chia seed mucilage worked in the recipe cited above, it seemed possible that psyllium mucilage would aid my recipe. Therefore I mixed up another half-sized batch of the black bean patty mixture according to its original  egg-containing recipe (1 cup black beans, ¼ sweated onion, and so forth) but with one addition: ½ tsp of psyllium powder. The resulting mixture was rather difficult to handle for it was very sticky and hard to work by hand. Nevertheless with some trouble I formed three patties from it and, after resting them in the refrigerator for ten or twenty minutes, I fried two of them up as before.

The results were quite pleasing. The burger held together well and there was almost no squeezing-out from between the bun during eating. Neither did the psyllium seem to contribute any "off" taste--or, at least, all the other seasonings succeeded in covering it up.

The next logical experiment is to attempt to use psyllium alone and exclude the egg for a truly vegan recipe. One change at a time...we must keep this as scientific as is possible for home cooking.

Psyllium powder experiment

A number of vegetarian and vegan recipes online call for the use of psyllium powder, the ground-up husk of the seed of Plantago ovata and related species. As I wrote in the previous post about vegan options for thickening and binding foods, psyllium contains a "mucilage" that swells to many times its volume in water, producing a fluid suspension with unusual properties. I had on hand a small quantity of psyllium powder and decided to play with it a little.

Half a teaspoon of the brown powder mixed well with half a cup of water and allowed to stand for 10 minutes produces a greyish, mobile fluid that seems to have low viscosity yet which holds the brownish particles of undissolved psyllium husk in what looks to be indefinite suspension with no evidence of settling.

Heating this suspension in a double-boiler arrangement causes a large increase in viscosity. Whether this is because the hot water dissolves more of the mucilage out of the psyllium powder or because there's some chemical change caused by heat (as happens with starch) is not clear to me. If the mucilaginous substance were isolated and purified it might be possible to determine the truth but that's getting rather far away from a cooking experiment. A fork dipped into the hot liquid and slowly raised draws out a long but weak strand, somewhat reminiscent of the "slimes" produced by cross-linking solutions of guar gum or polyvinyl alcohol with borax.

When the hot mixture is cooled to room temperature, its viscosity increases yet further and it begins to exhibit some gel-like properties. The mixture can still be poured very slowly and, when poked with a fork, the surface deforms without any resistance to pressure. Yet, even when the fork is poked in fairly deeply and then removed, the surface bounces back nearly to its original position. Refrigeration only amplifies this curious property. A finger poked into the refrigerated mixture comes away dry.

What use in cooking does this behavior suggest? The psyllium mucilage suspension, even before heating, is excellent at keeping floating particles dispersed. This suggests that the mucilage might be good at stabilizing colloids and perhaps foams. The great elasticity of the mixture after heating and cooling suggests that it might substitute to some extent for gluten in retaining the bubbles of CO₂ produced during baking bread, keeping the bread light; but since psyllium mucilage does not seem to "thermoset", at least at temperatures near to the boiling point of water, it seems possible that a bread held together with the mucilage would not have the desired resilience and would be easy to compress. The fact that, unlike starch or gelatine, psyllium powder leaves insoluble particles behind when it is dispersed in water might limit its utility--maybe trying to purify the mucilage is worth investigating.

Vegan thickeners, binders, and emulsifiers

As my experiments with homemade black bean burger patties (so far documented here and here) have helped to demonstrate, it can be difficult to come up with substitutes for the various substances of animal origin that give texture and consistency to foodstuffs. Collagen, gelatine, egg protein, egg lecithin, milkfat--all of these play roles in cooking that are hard to replace. The mouth feel and juiciness of a good beef hamburger patty, for instance, depend on the presence of collagen to keep the patty from falling apart and the presence of saturated fats that are solid at room temperature but melt upon cooking. Without some way of emulating the properties of these substances a black bean patty will tend to be dry and mushy.

In thinking about how to improve upon the recipe, it's worth examining what sort of options there are for the cook at home to imitate the properties of food constituents found only in animal products. Commercial food chemists have an easier time of it. They can freely use all manner of clever techniques and semi-synthetic derivatives of natural compounds (e.g. alkylated celluloses as thickeners, sucrose esters as fat substitutes) largely unavailable to the ordinary consumer, although a few of the substances long used in food chemistry are now to an extent available for home cooking thanks to the ludicrously-named fad of "molecular gastronomy". If all you've got to work from is what you can get at the local megamart, however, your options are limited. Still, some useful ingredients can be purchased over the counter, including...

Black bean burger patties, gluten version

In my previous post about homemade black bean burger patties, I speculated about ways of binding the ingredients together that might produce a firmer, less squishy patty. I also considered the possibility of doing away with the egg to make a truly vegan patty. There are a number of substances that might be good candidates for such a binder, but one of the easiest to get hold of--and, I thought, the most promising--was wheat gluten.

Gluten is best known as the protein that gives bread its tenacity, forming a tough network of elastic strands that traps the gases produced by fermentation. I thought it possible that this elastic network might serve to imitate the connective tissue that gives meat its firm consistency. I could have relied upon the gluten supplied by ordinary white flour but I thought I would have a better chance of success by using gluten flour, which consists far more gluten than plain flour; gluten flour is about 75% protein, compared to about 10% protein in all-purpose flour.

To test this, I mixed up a half-sized batch of black bean mixture according to the recipe given in the previous post except that, instead of adding half an egg as the original recipe called for, I added 1 tbsp of gluten flour and 3 tbsp of warm water. I honestly didn't know how much gluten would give the results I wanted so I settled on the 1 tbsp amount for the sake of simplicity. When mixed and mashed, this produced a very tenacious sort of paste, difficult to mash because of its strong tendency to form a single mass that clung to the masher. Strands of gluten were very easily seen during mashing. The resulting mixture, however, seemed to have approximately the same consistency as the mixture using egg as a binder. Possibly it could be handled with a bit less care and still hold together.

Frying up a patty with a little soybean oil as before, the result looked appetizing enough (see left), but the patty did not hold together better. In fact, it seemed to be even squishier. After just a few bites the patty is mushing out of the sides of the burger (see below left). It still tasted good, though.

It's possible that ten minutes in a frying pan isn't enough time to "set" the gluten. I have seen a recommendation in one meatless burger recipe to bake rather than fry or grill the patties. I can see how that might help but baking removes one of the great advantages of burgers, the fact that you can simply slap a disc of meat into a pan for a few minutes each side.

It seems that the answer to this problem lies elsewhere than with gluten. More on this question later.

Bread "starters", some preliminary successes and failures

After a few false starts (pun intended) I've had a little luck in using a so-called starter, rather than packaged yeast, to make bread from scratch. The starter is made by mixing flour or some other source of starch with water or milk and, depending on the variety of starter, other ingredients such as salt or sugar. The mixture is allowed to incubate for up to a week depending on the recipe, usually at somewhat elevated temperature (80° to 85° F is typical) although there are room-temperature starters. The idea is to provide a medium for naturally occurring yeasts or bacteria to grow and ferment. Some starter recipes do add yeast at the beginning to kickstart the process, but the idea is that you'll only have to do this once. For, once the starter is ready and fermentation established, you can use part of the starter and then propagate the rest of it with periodic additions of fresh liquid, flour, or whatever else is required. In essence a bread starter is like a stock culture in microbiology, kept continuously alive with periodic refreshment of the growth medium. Some bakers claim to have maintained a single batch of starter for decades, even centuries. Starters can also be refrigerated or even frozen, though before use the cold starter needs to be warmed and then allowed to stand for several hours or up to a day until it shows signs of life.

The most commonly used bread starter is the sourdough starter, which relies upon both yeast and Lactobacilli (and related bacteria). The yeast provides the lift as with ordinary bread; the Lactobacilli produce lactic acid, which gives sourdough its characteristic tang. So far I have failed to produce a working sourdough starter. Another rare and wonderful bread starter is used to make salt-rising bread, in which the leavening is thought to be provided by Clostridium perfringens, also the organism responsible for gas gangrene as it happens. C. perfringens produces a complicated mixture of fermentation products, including among other things propionic and butyric acids, which give salt-rising bread a unique cheesy smell and taste. After several failures I successfully baked a salt-rising bread and it was good, but the recipe is a tricky one--for one thing, the starter has to be maintained for a long time at a fairly high temperature to suppress yeast formation--and at least in all the recipes I've encountered the starter is not propagated.

Black bean burger patties, a first try

My mate and I have recently decided to go on a vegetarian diet for at least one month, for a variety of reasons. I've been rather looking forward to it actually because it will mean trying out new dishes and recipes. One constraint that we have placed upon ourselves is that we will not buy processed foods intended to imitate meat products; hence we'll be purchasing nothing like "Tofurkey" or soy sausage or Boca Burgers. We are, however, not excluding the possibility of making similar foodstuffs on our own, with the proviso that it must be done with ingredients that can be bought economically at an ordinary supermarket. (That excludes a number of things I wouldn't mind trying, e.g. using vegetable gums or specialty flours.) Since we're fond of hamburgers as a quick and satisfying meal, I figured that homemade vegetarian burger patties was a good first cooking project.

I read a number of recipes online but in the end didn't follow any particular one; I cobbled together my own recipe based on a couple ideas from the recipes I'd read, suggestions from my mate, and one brilliant little idea of my own that maybe made no difference.

The ingredient list is roughly as follows--roughly, because I didn't measure everything out precisely, particularly spices.

2 cups cooked black beans
½ of a medium-sized yellow onion
1 garlic clove
½ cup bread crumbs (I used panko because it was on hand)
1 tsp kosher salt
1 tsp black pepper
1 tbsp hot sauce
1 tsp cumin
½ tsp smoked paprika
1 small piece of dried porcini mushroom
1 large egg

Cooking blog test post

This is another test.