Here's the nub of the problem: we shop to restock the larder/freezer/fridge; we don't shop to fulfil a week's menu. We buy in bulk and have a well stocked larder and freezer. How do we account for that? Since most British households don't shop that way, how do you level the playing field?
After a lot of thought, I've come up with the following rules:-
1) Whatever is already in the fridge on 1st February is "free". After all, very few people start a month with a completely empty fridge.
2) Ditto the spices, tea, coffee, sugar and hot chocolate already "in the jar" in the larder. Top ups, however, do count.
3) I know the price of the meat, fish and cheese in the freezer - they will come off the tally as-and-when they are used.
4) Leftovers in the freezer are free. That means I don't have to work out how much a six-month old tub of Base or Sophie Dahl's Dhal costed when I made it months ago. The same goes for the lunch boxes stored in the freezer.
5) How to account for the dried beans, lentils and chickpeas we use, has occupied some considerable thought. We don't use everything all the time and I usually cook up dried pulses in batches, storing them in the freezer. I can't imagine going through more than 2kg dried weight of pulses in a month and, chances are, if I hadn't stocked up at Wing-Yip, we would buy a 2kg bag in rotation every month. We are almost out of Chana Dhal (split chickpeas) so a 2kg bag has been added to the shopping list and will represent the cost of all dried pulses used in February.
6) For rice, rather than buy some more (we have 12kg in stock), I will deduct the cost of 2kg of the cheapest rice from the tally.
7) Ditto flour but, in this case, it'll be the cost of either one or two of the standard sized bags of flour, depending on how large they are. (We use a couple of kilos a month baking our own bread, etc.)
8) In the pre-Costco days, we'd buy 6-8 cans of tomatoes each month. There are 7 in the cupboard right now, so I'll deduct the cost of 7 cans from the tally and limit us to 7 cans for the month.
9) What about other store cupboard items? Based on nothing more than the assumption that few people won't have something in stock, I'll tag 3 cans of tuna and two of pilchards/salmon as "free", together with one jar of sauce (either pasta bake or potato bake). Ditto a box of breakfast cereal and a tin of baked beans.
10) This is a grocery spend challenge, so it includes items such as cleaning products, washing powder, toiletries and tampons - anything that would normally be purchased at the supermarket.
Having set the rules, right now I'm contemplating how to spend the money. £50 isn't a lot of money - it's £12.50 a week or £1.78 a day which is a scary figure when you consider that's groceries for two people. The only way to make it work is to break it up into "shops": £20 for the main supermarket shop; £10 for two trips to the farm shop for vegetables and eggs (£5 a trip); £15 for meat and/or fish from the freezer; £5 for a second, top up supermarket visit.
Will we starve? No. Will we have a stand-up row in the middle of Tesco at some point? Probably. Will we get through February without breaking the £50 budget? I really don't know. Wish us luck.
(is anyone else up for the challenge?)