Warning and Disclaimer: This post is about cooking and stuff whilst backpacking. Like any meal it should be taken with a pinch of salt. Fellbound does not accept any liability for any loss, injury or damage that results from this blog post, howsoever caused. He also wishes to remind readers that he is supported by a crack legal team (Messrs Cosh, Basher and Hardcase) who will deal with you as deemed appropriate by Fellbound if you so much as suggest that this blog post proves that Fellbound is an anally retentive cretin who needs to count grams less and get out on the hills more. Finally, he needs to point out that any gear referred to in this blog post was purchased by Fellbound using his “gold plated public sector pension” (© Daily Mail, Daily Express, Daily Telegraph, The Sun, The Times etc., in fact all national newspapers except The Grauniad, The Daily Mirror and The Socialist Worker). Fellbound is still willing to accept any offer of free gear (which remains remarkably absent in the Fellbound household) from any reputable manufacturer or retailer and promises to review any free gear if he can get round to it.
An interesting post on Alan Rayner's blog recently about the TGO Challenge resulted in a few comments about the respective efficiency of gas and alcohol (meths) stoves in relation to the weight that you have to carry using these systems. The perceived wisdom is that on longer trips gas is lighter than meths. Whilst I have always tended to believe this, I think that the position is rather less straightforward. This is not least because the comments on Alan’s post related to the weight of the fuel and did not refer to the weight of the cooking system itself, nor to the frequency of resupply stops. So whilst walking Hyperdog along the lanes this morning I pondered on the issue. When I got home I got the kitchen scales out, set up several spreadsheets and developed what will, I am sure, become known in mathematical and backpacking circles as “The Fellbound Theorem”. In short this can be summarised as follows:
“When counting the grams for cooking your calories there is no clear answer as to whether gas or alcohol is lightest so your best bet is to eat your dinner and enjoy the view”.
This earth shattering conclusion is underpinned by a set of assumptions based on my own equipment and my particular way of cooking and frequency of brewing up. The outcomes might be completely different for others. It does not take account of factors such as the speed and cleanliness of gas, the reliability of meths stoves, or whether you like the odd slug of meths as an aperitif. My findings now need to be the subject of peer review to test their robustness. You, dear reader, are the peers.
Assumptions based on my own way of doing things (aka “the right way”):
- There is a minimum amount of weight you have to carry for the stove set up even before you add fuel. I will refer to this as the “stove base weight”.
- My gas stove base weight: A little Optimus thingy (94gr), with an Optimus windshield (64gr) and canister feet (24gr) for stability, gas cartridge. Depending on length of trip and resupply possibilities the cartridge will likely be either 100gr (weighs 200gr when full) or 150 gr (weighs 380 gr when full). So gas stove base weight = 282 or 332 gr., dependent on size of cartridge carried.
- My meths stove base weight: Traildesigns Sidewinder cone in Tyvek sleeve (37gr), aluminium support pegs (14gr), Trail Designs stove (16gr), 500ml meths bottle (10gr). So meths stove base weight = 77 gr.
- So the base weight for the two set ups is either 77gr for meths or 282/332 gr for gas. At my rate of fuel use (see below) meths is definitely lighter for a 2 or 3 day trip.
- Amount of cooking: 4 brews per day, plus one boil for instant porridge, one for an instant soup and one for a dehydrated meal.
- Rate of fuel use: On the TGO Challenge I ran out of gas using a 230 gr cartridge on the 9th day of cooking ie 25gr. of gas used per day. Meths use is a generous100 gr per day.
Right let’s put all this together. I will not try to embed my fancy spreadsheets because I don’t know how to, so here are some charts created from these and based on the above:
The first chart is based on a two week trip in the wilderness entirely unsupported, with no resupply of fuel. You therefore need two gas cartridges, a small one and a large one (that situation is 'Gas 1' in the chart). 'Gas 2' is where in that wilderness you come across a conveniently located waste bin on the very day (Day 5) a gas cartridge empties so you can chuck it away.
The second chart shows a more likely situation on the TGO Challenge. This assumes you can buy extra fuel every 4 days. Note that resupply every 4 days is the optimum for gas if using 25 gr of gas per day as it allows the small 100 gr cartridge to be carried, although you would be running on empty when you got to the shops.
What both of these charts show is that on certain sections of the trip you carry less weight if using gas; at other times on the trip you would be carrying less meths.
Of course all this is very crude and needs refining. For example, the charts show that for a TGO Challenger meths is heavier in the earlier days. However, Challengers tend to walk shorter days initially, and longer days later on. So what I need to do next is set up some spreadsheets to examine weight carried against the numbers of hours on the trail on each day of the trip. This information could then be examined against the numbers of calories that would need to be consumed to have the energy to carry these weights for these periods, which in turn would have implications for the weight of food to be taken on your trip. All of this is clearly a suitable topic for a PhD so I must start to put together my research proposal……