Zapping my way to the top.
Over the past few weeks, it feels like I have spent more time talking to Gemini than to any single person in real life. AI is helping more people in the workplace but what about easing things round the home?
I wondered if Gemini can help me lower my carbon footprint?
Of course, not being human, Gemini needs a question to get started. Mine was “can you help me convert this recipe so I can cook it in the microwave?”
I’ll bit, what recipe is that?
Soup. I know I have a induction hob but putting on a big ring for soup cooking over 40 minutes seems a bit wasteful, somehow.
There are several things I use a microwave for: roux sauces are done in second rather than minutes, fish is incrediable, chocolate fudge sauce is a guaranteed outcome. I know how much time is saved and great food I have enjoyed in cookware that goes straight into the dishwasher. What’s not to love, from that point of view?
Of course, for the “Driving off the grid” section of this blog, microwave ovens are incredible. There is no waste heat, it outperforms induction hobs for the sorts of food you would normally cook there.
My real winners at the moment are my home made yogurt, and the chicken stock.
So after zapping my fish dish this lunch time, I got tapping, exploring what I could do next with making the most of my microwave.
There are three winners, I think. A vegetable stock for my soups, some fish stock made from some fish I’ve cooked (definitely one for the freezer, my partner does not like fish!), and some conversions for my favourite soups.
A vegetable stock to be less wasteful.
Before I got in to cooking from scratch to such an extent, stock seemed like a waste of energy, when you could buy a cube or pod full of tasty stock. Hours bubbling away on the hob, boiling out bones did not sound like my idea of fun, not to mention the washing up.
Finding my chicken stock recipe was a wow moment. But finding a sensible looking vegetable stock seemed rarer than a unicorn, hen’s teeth, and flying pigs. Such things did not seem possible.
In comes a session with Gemini talking about home cooking, so I ask: “I’d love to make my own vegetable stock. Could you suggest how I could do that in the microwave?”
An initial suggestion was refined, working out alternatives to things I knew we were cooking the next day – I wanted to do a vegetable stock for our traditional Sunday evening soup. Well, the stock wasn’t bad, taste wise. 250ml of tasty stock out of things I would normally bin!
For the soup, I put far too much water in with it. When I cook the soup in a pan, covering with water is absolutely necessary. So I did the same with the microwave version – tasty but incrediably wet! Next time, I’ll just add the 275ml of stock.
But the speed, the hands off nature, the lack of piles of hard washing up. I may be a convert!
What about the verdict, beyond the taste, isn’t tradtional soup on a hob better than using the microwave?
It’s really marginal, energy-wise, not least because the microwave is running at 660W for the whole 15 minutes, where as once the soup is simmering, the induction hob is using very little power.
We’re losing some energy with the induction hob to the pan and its lid (85% efficient compared to the 90% of a microwave), but it’s really, really close.
Where the microwave does probably win hands down is the cleaning up process. Using the microwave, I used five pieces of equipment – a knife, litre jug, a silcon lid, a small measuring jug, and a stick blender to cook and serve. All but the small measuring jug goes straight into the dishwasher.
The traditional method uses a knife, a wooden spoon, a pan and lid, a blender goblet, and a ladle to spoon the mixture from the pan into the blender. Six pieces and that’s before we start to break apart the blender goblet and its lid – another five items.
Many of these cannot go in the dishwasher, hello wooden spoon and engine part of the blender goblet, but the pan and blender goblet are huge. Both take space that means the dishwasher would have fewer items for a full run, so often wash them by hand.
Gemini suggested that the induction hob might edge ahead, but I pointed out that for the total cost of ownership, the prize goes to the dishwasher, and that’s forgetting the time I’d be standing on my feet stirring the pot as the dry vegetables get cooked in the butter before the stock is added.
- Microwave = 15 minutes * 660W = 165Wh = 0.165 kWh.
- Stick blender = 3 mintues * 1.2 kW = 60Wh = 0.06 kWh.
- Dishwasher = 50 things in the dishwasher, of which this meal uses 4 of them, which runs at 0.54 kWh, so 0.0432 kWh.
Total power used to cook the soup in the microwave = 0.2574 kWh.
At £0.2656 per unit = £0.07, as a total charge, plus the standing charge.
A cheap evening meal on a Sunday evening, partly made with left over peelings from lunch. Next time, which much less water in it, check out the revised recipe at Microwave Stilton and Celery Soup!
Compared to the induction hob?
Ah, so there are more steps making up our 40 or so minutes of cooking time, but the induction hob probably used around 0.5767 kWh. If we keep the stick blender and everything else the same (though there is significantly more manual washing):
- Induction hob = 40 minutes * various power levels = 0.5767 kWh.
- Stick blender = 3 mintues * 1.2 kW = 60Wh = 0.06 kWh.
- Dishwasher = 50 things in the dishwasher, of which this meal uses 4 of them, which runs at 0.54 kWh, so 0.0432 kWh.
Total power used to cook the soup on the induction hob = 0.6799 kWh.
At £0.2656 per unit = £0.18 total cost, plus the standing charge.
Wait, isn’t that more than 2.5 times the cost, plus the washing up, and the time!
Yes, yes it is. Working out how to do things in the microwave (if possible) really does pay off.
Posted: February 7th, 2026 under Driving off the grid.