Case Study: Sourdough Crackers

Project summary

Regenerative agriculture utilizes techniques like conservation tillage, cover crops and crop rotation to build up and sequester carbon in the soil. If yields can be maintained similar to conventional agriculture, then this could be the future of food production. So when a startup snack food manufacturer asked us to quantify the carbon benefits of their crackers made with wheat and other ingredients produced using organic/regenerative methods, we quickly leveraged our tools and database to put together a  life cycle assessment (LCA) study comparing crackers made with conventional and organic inputs.

System modeled in this study

The diagram below illustrates the supply chain for a packaged box of sourdough crackers. 

The functional unit is a packaged box of crackers (net weight: 4 oz). The system boundary is cradle-to-gate from the perspective of the cracker manufacturer. We used the same supply chain to compare a box of crackers made with conventionally produced wheat and sunflower seed (these are the two primary agricultural inputs to the cracker production) vs. a box of crackers made with organically produced wheat and sunflower seeds. We had actual secondary data for the conventional production systems in our life cycle inventory (LCI) database. We modified these conventional systems to create hypothetical LCA models for organic production systems in order to quantify the benefit of switching to organics. 

Organic farming systems are generally characterized by the types of inputs used, such as fertilizers and pesticides that are not synthetically produced and are non-toxic. Based on information from the actual farms that produce the organic ingredients considered in this study, we know that these organic systems also use regenerative farming methods to build and preserve soil carbon. Therefore, we refer to these systems as “organic/regenerative” in this report (or just “organic” for short).

General assumptions

An initial LCA study often starts with a number of assumptions and placeholders that are later refined using higher-quality data. For the two cracker production systems modeled in this study, the data available initially included the list of ingredients (including the weights of ingredients), the production and processing locations of the ingredients, and the co-packer location where the final production and packaging take place. We used secondary data from our LCI database to model the production and processing of the conventionally produced ingredients.

In addition, we made several assumptions and used a number of placeholders as documented below in order to fill in the necessary preliminary data for organic production, waste disposal, processing, packaging, and various minor ingredients:

  • For the organic/regenerative farming systems, the on-farm energy use and yield are assumed to be the same as conventional systems for which we have data in our LCI database. Past LCA studies (including one of our own) have shown that organic farming systems often suffer from lower yields relative to a conventional system; however, farming techniques are improving and we expect our assumptions to be replaced with actual data from the specific farms in a future iteration of this LCA study.
  • For the organic/regenerative farming systems, the primary fertilizer is assumed to be manure-based compost supplying the same total nitrogen per acre annually as the synthetic fertilizers used in a comparable conventional system. We elaborate on this further in the “Farm-level LCAs” section below.
  • For the baking process at the co-packer facility, crackers are assumed to use comparable energy as bread rolls for which we have data in our LCI database.
  • Sunflower oil production is assumed to be located near the seed farm, and the waste is composted close to the production facility.
  • Although extensive, the LCI database has a finite number of entries, so substitution of products with similar profiles follow: we swapped malt for the yeast extract, acetic acid for lactic acid (since they have similar fermentation processes), and soda powder for baking powder.  Each of these substitutions are for an ingredient that comprises 1% or less of the formulation.  
  • Packaging material is assumed to consist of a 29.08g paperboard carton and a 5g polyethylene (HDPE) plastic liner.

LCA tools and LCI database

We used our new carbon modeling tool, CarbonScope, to conduct the two product LCAs in this project. FoodCarbonScope was used for the farm-level LCAs of the hypothetical organic/regenerative wheat and sunflower seed crop systems. The LCI database underlying the analysis is CarbonScopeData.

Farm-level LCAs

Since we did not have detailed production data for the two primary agricultural inputs used in the manufacture of the crackers — organic wheat and organic sunflower seeds — we created hypothetical organic/regenerative systems based on the conventional production systems for which we had data in CarbonScopeData. We assumed that the energy use and yield per acre would remain the same between conventional and organic systems, and the primary differences would be in the fertilizer application and soil carbon sequestration. The organic farms are assumed to use manure-based compost, based in part on information received from one of the farms, as the primary fertilizer (NPK percentages =  1.5:1:1.5). 

We made a few additional and reasonable assumptions about compost:

  • Compost mineralizes and releases 10% of the total compost nitrogen per year.
  • Compost has been applied long enough that sufficient amounts of total mineralized nitrogen,  phosphorus and potassium are available to the crops each year.
  • Compost added each year must supply the equivalent of 20% of the synthetic nitrogen through mineralization; the other 80% would come from previous years’ compost applications.

The table below summarizes the key parameters used in the farm-level LCAs of the two commodities. The wheat farming system is considered “transitional” because it is still within a 20-year period following a switch from conventional to organic production. The sunflower seed farming system is considered to be in “steady-state” because the organic production was established more than 20 years ago. The climate and moisture regimes were set based on the locations of the farms. The soil type was set based on information supplied by the farms. The last column in the table sets the carbon inputs to soil as one of four discrete levels (low, medium, high, high-organic), and we chose the “high” level based on our understanding of the farming systems. These parameters are based on IPCC tier 1 methodology, and are used in the farm-level LCAs by FoodCarbonScope to estimate changes in soil carbon during the transition from conventional to organic/regenerative farming.

Of the two crop systems, only the wheat gets credit for soil carbon sequestration as it transitions from a conventional system to an organic/regenerative system. Soil carbon generally increases during such a transition as illustrated below and is calculated using the parameters summarized above. The numbers in the diagram below are for illustration only and do not represent the actual systems modeled in this study. 

The table below summarizes the cradle-to-farmgate LCA results for the two agricultural commodities considered in this study:

Product LCA results

The table below compares the life-cycle impacts of a box of crackers made with organic ingredients produced using regenerative methods vs. crackers made with conventionally produced ingredients. Organic production results in 30% lower greenhouse gas emissions (quantified as Kg CO2e), and all of this is attributable to the difference in agricultural methods. This difference arises from the “Inflows” category which includes the purchased agricultural commodities. The LCA results clearly show the benefits of switching to organic/regenerative production, but with the caveat that credit for soil carbon accumulation can only be taken during the transition period.

The other interesting insight from the results is that packaging dominates the life-cycle impacts of the products. When the ingredients are plant-based with fairly low carbon emissions, transportation and packaging can sometimes take on an outsized role. The table below shows the top four contributors to carbon emissions in the life cycle of the organic cracker product. Two of these are the packaging materials. The paperboard used to make the carton contributes about half of the total carbon footprint of the finished product. 


This LCA study has demonstrated the significant potential for reducing the cradle-to-gate greenhouse gas emissions of the client’s cracker product by sourcing agricultural commodities from farms that are using organic/regenerative methods. It should be noted that the actual supply-chain data for the production was supplemented with several assumptions and placeholders, so these results should be treated as the first step in the process of quantifying and optimizing the climate impacts of the cracker products.

What to expect when working with CleanMetrics on an LCA project

Susan Cholette, VP of Consulting Services

So you’ve decided it’s time to see what sort of environmental changes your company can make,  and you’ve chosen us as consulting partners in this journey, congratulations!  But where to start?  And what should you do to avoid wasting your time or money?  

Do you want to perform a company-wide assessment or focus on a key product that you think may have some opportunities for improvement?   While we can help you perform a corporate greenhouse gas inventory analysis, let’s assume for now you have decided on the latter, which means doing a life-cycle assessment (LCA) to calculate the carbon footprint and other environmental impacts from the production, delivery, use and disposal of a product or product categoryWhile FoodCarbonScope is an option for a primarily agricultural product, it’s likely that CarbonScope will be the tool of choice.

The first phase of any LCA is to define the goal and scope. We would recommend a quick consultation at this point, since this prep work will ensure you are collecting the right data. During this phase we set the system boundary and the functional unit, and if you are not yet certain of these, here are some things to consider.   While our tools can model your product’s journey from cradle-to-grave, if your product is a single-use product, like a snack, or you have very little control or insight into its downstream distribution, cradle-to-gate may be sufficient.  Packaging often has large impacts.  We recommend making use of our system diagram template  to visualize your product and its associated supply chain.  

The next phase is the inventory analysis, which includes collecting all the information on your product:  the bill-of-materials and associated sourcing and delivery information, the energy purchased, waste management, and potentially some agricultural specific parameters for farmed ingredients.  If you outsource this phase of the analysis to consultants, it can quickly rack up billable hours, as the consultants have to learn about your product, get connected with your operations department or your vendors, and compile this information.  (And you still had to take the time and effort to make all these connections happen).  

We recommend using our spreadsheet template to collect as much of the information yourself as possible.  Building a model is an iterative process: you may not have detailed information on all the ingredients, parts or components, and so we advise using placeholder data in the interim before you delve deep into researching tertiary ingredients.  The template includes places where you can list assumptions and indicate the degree of confidence in your data.   While we are always available to consult with, you are undoubtedly the experts in how your product is sourced, manufactured, and delivered.

Phase three is the impact assessment. While some companies may purchase a subscription to CarbonScope and perform this next step themselves, we would generate results for the three impacts we track: embodied carbon (in Kg CO2e), embodied energy (in MJ), and embodied water (in liters). Through tabular and graphical data we can quickly show you where your hot spots are, and by doing some sensitivity analysis, determine where the model may need to be fine tuned and more data collection is called for. 

If, however, the results seem sufficiently robust, the final step would be to interpret the results and make recommendations for change.  We would generate comparisons if any alternate scenarios were defined.  We typically write up a short Word document presenting key results and recommendations, but we will not deluge you in or bill you for pages of boilerplate.   You will also receive a detailed Excel spreadsheet reporting all the impacts by stage, processes, and scope, so that you can slice and dice the data as desired. 

At this point, it’s likely that one of your employees who has worked with us has learned a lot about our tools and methodological approach.  Should you decide to do some further analysis on alternative sourcing or production methods or perhaps consider another product for analysis, we can of course help you with more of our consulting but you also have the option of buying a subscription to CarbonScope and relying on your in-house expertise.

CarbonScope available now

When we launched CleanMetrics 2.0 at the beginning of 2020, we started with a vision. It has been clear that businesses of all sizes can do a lot to address climate change. But before they can cut their emissions, they need to know where they stand without spending a ton of money and time. In the brave new world of low emissions, carbon modeling and emissions accounting should be fast, easy and inexpensive.

This was the motivation for kicking off an intense period of software development and road testing. We are finally at a point where our new flagship carbon modeling tool, CarbonScope, is ready for users.

As we architected this web app, we recognized that the same life-cycle framework would serve two common, but often distinct, carbon modeling applications equally well: corporate greenhouse gas inventory analyses and product life-cycle assessments. So CarbonScope does both, using a shared life-cycle inventory database and a shared modeling paradigm. The design is simple and minimalistic, and the functionality is easy to use and intuitive.

CarbonScope comes packaged with an hour of training videos designed to get new users off to a fast start. Annual subscriptions start at just $300 for commercial use. Check out our pricing page for consultant, teaching/research and student subscriptions.

As always, email us at with questions, comments or feedback.

Our new pricing structure

In a recent Medium post, we made this statement: “If we are going to bend the emissions curve, emissions accounting must become as commonplace as financial accounting.” This will be essential if we are going to have any chance of holding the warming to 1.5°C or even 2°C.  We also made the case that the two major obstacles to doing this on a large scale across the economy are cost and time.

We have been working since the beginning of this year on new carbon modeling and emissions accounting solutions designed to break through these two barriers. We are now getting ready to release our new carbon modeling tool, CarbonScope, on a subscription basis and our service offerings built around our software tools.

We are excited to announce our new pricing structure designed to make emissions accounting affordable for most companies and organizations. For companies that are interested in doing their own GHG inventories and product LCAs/product carbon footprints, an annual CarbonScope subscription starts at just $300. This should be sufficient for most companies, but heavier users can purchase additional credits as they go.

For companies that would rather have an expert do the analysis, our consulting prices start at just $1500 per project. We have tried to leverage our software and automation to keep our costs to a minimum. We are also prepared to help customers transition from consulting services to direct use of our tools, using the carbon models developed in consulting projects as a starting point.

We want to share and collaborate where we can. We have made our tools super affordable for professors, researchers and students — because we all depend on new ideas and cutting-edge research to push climate solutions forward. We also have very affordable pricing for consultants — because we ultimately want as many companies as possible to take on emissions accounting.

Email us at if you have any questions.