Wood for food: a primer on pyrolysis

by Guillemette Barthouil  Overview Smoking is valued nowadays not only for preserving food, but also as a distinct set of flavours that can reflect the landscape of the region. Pyrolysis, the thermochemical decomposition of organic matter, breaks apart the three main components of wood: cellulose, hemicellulose and lignin. Each influences the colour, flavour, preservation and surface texture of the food – this information is summarized in Figure 4 below. Controlling pyrolysis is the key know-how involved in good smoking. Overall, for best results the wood moisture should be lower then 25% and its combustion temperature around 400°C. “Smokingis one of the oldest food preservation methods, probably havingarisen shortly after the development of cooking with fire.”(Encyclopedia Brittanica) Mostarticles I have read for this research have started with the samestatement. Humanity has used this technique for so long, it seemsrather strange to try to explain it – but that is our job. … Read more

Waxed Plums

trials by Sarah; post by Guillo, Avery, and Josh Is it possible that waxing fruits, a symbol of our large-scale food distributionsystem that values appearance and practicality over taste, could be usedinstead for deliciousness? In fact, many fruits when ripe produce a natural wax coating on theirsurface to reduce the water permeability of the skin. Pick an apple from atree, rub it on your shirt and it shines; the natural waxes on the apple’ssurface are polished. In addition to the wax, the surface of these fruits oftenhost different wild yeasts and other small ‘debris’. Large- scale producers, inorder to get rid of these yeasts and others microorganisms which can decrease afruit’s shelf life, wash their fruits then recoat them with approximately thesame amount of edible wax. But here at the Lab we love wild yeast and bacteria. At the end of September the plum season was nearing an end in … Read more

Vinegar Science pt. 5: Recipes

by Arielle Johnson Overview What follows in our last post in this 5-part miniseries on the hows and whys of vinegar making are some of the recipes we developed using the previously discussed techniques and methods. There are three recipes: one for celery vinegar using the ethanol addition method and single (acetic) fermentation; one for strawberry vinegar using a double (alcoholic and acetic) fermentation and aquarium bubbler; and one for roasted koji ale vinegar, using a triple fermentation (fungal saccharification, alcoholic, and acetic), and passive aeration. Young Celery Vinegar: 1. Juice celery in a juicer – you should get a yield in juice of approximately 50% of the initial weight. 2. Add high-proof alcohol to the celery juice until the mixture has an ethanol concentration of 6-8%. If you’re using 80 proof liquor to do this, only 40% of what you’re adding is ethyl alcohol so plan accordingly. 3. Add 20% … Read more

Vinegar Science pt. 4: Slow Malt Vinegars with Nordic Flavours

Vinegar Science pt. 4: Slow Malt Vinegars with Nordic Flavours Added on February 19, 2014 by Arielle Johnson. by Arielle Johnson Overview Traditional malt vinegar, most commonly doused on fish and chips, is not regarded with much culinary interest. In our quest for developing Nordic vinegar, we found this widely produced, commercial malt vinegar as a source of inspiration for developing beer-base vinegars that held the potential for more complex and interesting flavors. The experimentation consisted of two types of malt-beer bases. For one, we mashed and fermented pale ale barley malt in a style similar to home-brewed beer. For the other, we brewed a koji-beer by creating a mash as if koji were malt. This method of brewing and fermenting koji proved unsuccessful, so we tried using another type of grain-based alcohol as our base. We created barley koji sake, which yielded much better results. To these malt vinegar … Read more

Vinegar Science pt. 3: Sensory Analysis

by Arielle Johnson Overview With all of these techniques being put to the test, comparison is needed to to determine whether the different vinegars are interesting enough for future elaboration. In this third instalment of our 5-part miniseries on vinegar science, we detail the process of sensory analysis – including assembling a trained human panel, generating flavour descriptors, identifying reference standards, and conducting replicate sets of tests – that we used to qualify their specific characteristics and perhaps to reveal which processes had led to a tastier result. Overall, it seemed that the vinegars that had ended with some residual sugar and had undergone more stages of fermentation yielded tastier vinegars. While we taste all our experiments carefully and mindfully, we decided for this vinegar-investigating project to use descriptive analysis to profile the flavours of the vinegars. This meant that we could get some hard data to work with, and also explore … Read more

Vinegar Science pt. 2: Seasonal Summer Vinegars – A Rapid Approach

by Arielle Johnson Overview Alcoholic liquids are usually created by allowing yeast to ferment a sugar-rich solution (juice, syrup, etc.). By using distilled spirits, however, we are able to create dilute alcoholic solutions (usually between 5 and 9 percent ethanol by volume) using ingredients that are not usually rich enough in sugar to ferment into an alcoholic product. This post, part two of a five-part miniseries on vinegar science, details how this idea can be combined with a few simple pieces of readily available equipment that enable us to speed up the rate of aeration of the fermenting vinegar, to create interesting vinegars out of wines, juices, and teas much more quickly than traditional methods. As part of our investigation into new and delicious vinegars, we wanted to experiment with fresh and seasonal summer ingredients, but didn’t want to wait too long to evaluate the results. An aquarium bubbler with an airstone, we … Read more

Vinegar Science pt. 1: On Flavour & Vinegar as a Process

by Arielle Johnson OVERVIEW Acetic bacteria + Alcoholic liquid + Air = Vinegar Producing vinegar is an exploration of the ways in which raw ingredients and microbial populations interact to produce interesting, delicious, and complex flavours. In this first post of a five-post mini-series on vinegar, we give a brief overview of the fermentation process and the ways that acetic bacteria preserve, transform, and deepen flavours through manipulation on their environment. The essential components of a vinegar fermentation are a liquid that is somewhat acidic and contains ethyl alcohol (between 5 and 18% by volume), acetic bacteria, and oxygen. The mixture can be aerated passively or actively. The passive method is more traditional – all other things equal, the ratio of surface area to volume determines the rate of the fermentation. The active method involves aerating the mixture with a device like an aquarium pump, which can complete the fermentation in … Read more

Elder – a love story

by Justine de Valicourt Overview Investigating hydrogen cyanide was a gateway to full-fledged elder-obsession. This post explores the complexity of Sambucus nigra, the elderberry tree, in folklore and throughout its traditional and modern uses in woodcraft, horticulture, medicine, and cuisine. The plant is considered toxic, but the poisonous alkaloids and glycosides are contained mostly in the bark, leaves and stems. Most scientific literature considers the ripe berries safe when consumed in moderate quantities. However, we tested raw elderberry juice on the lab team and all of us except one felt very nauseous for the few minutes after ingestion. We still don’t fully understand the causal mechanism for this effect, so we recommend to gently heat or ferment the fruits/juice before consuming. The flavour is much improved with acidity, which fermentation (kombucha and vinegar, for example) seems to be a good way to achieve. Can someone fall in love with a plant? … Read more

Bog butter: a gastronomic perspective

by Ben Reade. This paper was first published in ‘Wrapped and Stuffed: Proceedings of the Oxford Symposium on Food and Cookery 2012′. The complete Proceedings is available from Prospect Books; a video recording of the presentation of this paper can be found here (starting at 33 minutes), and a podcast about it here. People dig for peat. Once dry, this peat burns hot and lets off an evocative smoke that brings to mind the cooking and heating methods of yesteryear. The peat-cutters harvest their quarry from dark brown, water-logged quagmires. Occasionally, these accidental archeologists discover artifacts left by people long gone. One such artifact, among the most commonly unearthed items from the watery, misty bogs of Ireland and Scotland, is known as ‘bog butter’. Due to the frequency of these findings and its mysterious nature, it has been fairly well studied from an archaeological perspective, perhaps the most thorough investigation being … Read more