Four things we learnt about high altitude meal preparation from our Mt Trishul (7120m) expedition

In my previous article on my personal website, I summarised our key considerations for high altitude meal planning into the BOLTS acronym:

Balanced Diet One Pot Meal Light with Minimal packaging Tasty to everyone's liking Special Treat

While the details of each of the consideration still hold, I would like to add a few handy tips that we learnt from our expedition.

1. Always test it out!!

Test it out!! Especially if it is a new food that you are trying out for the first time. That is common sense, you must be thinking. Well, in our defense, we figured out that there is not much risk if it’s just preserved vegetables or some random off the shelf seasoning. How wrong could these items turn out to be? Whatever the answer is, trust me, you do not want to be like us and find that out at a camp that is 5100m high. We had to diligently remove those preserved vegetables strands from our next few meals (we have prepped each meal by putting all the ingredients for one meal in a zip lock bag each)

Going for an adventure is fine but dinner time does not have to be an adventure.

2. Variety brings gaiety

In Singapore, there is this Chinese sausage known as Lap Cheong. It is a marinated, salted and smoked sausage that goes pretty well with fried rice. It adds a sweet flavour to the rice. I used to love it (Yes, USED to)!

Because the preserved sausage is light and can be kept for a long time, we thought that it could be a great source of meat that meets our 3rd key consideration – Light with minimal packaging. The first few meals we had in the mountains, I was fishing for all the sausages and wished I had more. They were delicious. But not when you have them for every single dinner afterwards.

It’s been 8 months since that expedition and I still do not dare to have Lap Cheong again. Whenever I pass by a hawker stall that sells that, I dash past. So, varying your source of meat, carbs and vitamins is critical on long expeditions. We found that luncheon meat was great, it was full of fats and even came in plastic container (lighter than metal cans). We still need to find more meat substitute that can lasts for weeks other than luncheon meat, bakwa, dry shrimps and dry ikan billis.

3. How to cook faster

The big challenge at high altitude is that the time to cook increases by quite a fair bit. Both due to the cold and the high altitude.

High altitude

At high altitude, air is less dense. Thus, liquid needs much less energy(heat) to match the vapour pressure and turn into gas, aka boiling. When boiling temperature is lower, it takes a longer time to cook meals.

Cold

The biggest challenge is not the lower boiling point though, but rather the cold. Liquid or multi fuel works better (comparing to cannister) at subzero temperatures but then you must deal with priming. Priming is when you must light a bit of the liquid fuel first for the stove to get warm enough so that when you open the stove again, the incoming liquid fuel vaporize into gaseous flame. You can imagine that this is a tricky bit and there might occasionally be burst of flames. That is not ideal for us as at high camp. We would be cooking within our tent vestibule because of the cold.

Additionally, it requires a bit more dexterity to operate compared to canister and in times of real bad weather, our cold fingers would be cursing at the system. To top it up, it is hard to find clean liquid fuel (methylated spirit) everywhere and we might end up using kerosene which produces headache inducing vapours. Worst thing to have at high altitude!

As for canisters, it is simpler to operate. However, as temperature drops, the vapour pressure inside the canister drops so much that no fuel gas comes out from the canister. So, we found a way to work around it.

How do we make it work for us?

Firstly, we always keep the canister somewhere ‘warm’ when not in use.

Secondly, we always use an integrated canister system (jetboil or MSR reactor) to boil the water first. Then we transfer to the less efficient pocket rocket to cook our meal. Yes, that requires us to have two stoves but the pocket rocket is very compact and light and having two stoves allow us to keep boiling water (to refill our water bottle) and prepare the meals at the same time.

Thirdly, we always use a DIY heat exchanger to keep our canister warm. This is the tricky bit. Heating back the canister too much has a risk of exploding. Some people choose to keep the canister between their thighs but that requires more effort and synchronization to prevent spillage.

Lastly, keeping to One Pot Meal helps us in reducing the cooking time if we had to cook a few dishes.

4. Know your stats

It is important to know how much fuel you consume. Else you will end up in the same situation as us and carry an extra 10 canisters to 5700m before bringing them back down to town. I mean, having extra is always good for emergency but ours was way too much.

We were operating the gas canisters between 5000m to 6200m. We used them to melt snow and boil water both for drinking and preparing our breakfast and dinner. Our dinner was always one pot meal. We always boiled water using the reactor and always had our DIY heat exchanger on. Based on those parameters, we were using three fifth of a 230g canister per person per day.

We hope that this information might be useful for you to plan for your next big expedition. Let us know if you have any other formula that worked for you.

Our go to items

We loved every aspect of the BOLTS system and would repeat them. I would also like to share with you the things that we tried and really enjoyed:

1. All our dried fruits (especially mangoes)

2. Self-made dehydrated vegetables (not the bad one that we bought)

3. Instant paste (such as nonya sambal, sweat and sour) that really added flavour to our meals and warmth to our heart.

If you do have other tips that work for you, please let us know. We would really love to hear about them