This guy just really, really wants to use his slide rule. A cheap gram-accurate scale and an electronic calculator are a more...scalable kitchen solution.
Also, not all ingredients in a recipe scale linearly--most notably spices, tinctures, and any fermentation components.
The point of the article is that he can set the C and D scales to the proportion he needs, one time, and then just move the slider around for each ingredient, rather than doing a different calculation for each ingredient. Knowing when to vary the proportion is just basic cooking knowledge which would have to be applied either way.
>The point of the article is that he can set the C and D scales to the proportion he needs, one time, and then just move the slider around for each ingredient, rather than doing a different calculation for each ingredient.
Is punching a number into a calculator and then multiplying by M (memory function, for the scale factor) really that much work than carefully sliding tithe slider into position and reading/eyeballing the output?
Interesting. Could you give an example? The only example I could think of is when one is making a big ball of something and needs to cover the surface with another ingredient or preparation then it would scale as ^2/3.
One everyday example is how when cooking rice in a pot, you don't scale water with the rice directly.
You know how people stick their finger in the pot, touching the rice, and add water up to some reference point like a knuckle?
Evaporation is more about the water surface area and not the total volume, so a fixed depth above the rice is used for estimation. HN discussion on the physics: https://news.ycombinator.com/item?id=24021195
People should just be into slide-rules period. Particularly in the West. We are always so amazed when people in Asia beat people with calculators using their abacuses, but the West had its mechanical computing device too, and like the abacus it can beat a calculator if used well.
Last year I picked up a bamboo Hemi and worked through the (70yo!) workbook. The trigonometric scales are cool. Making a single slide to find all the sides of a triangle is surprisingly satisfying. It got me to realize that, sliderules with the right scales can solve the roots of any 3-variable equation. I guess this is why there was a proliferation of industry-specific sliderules back in the day.
More generally, aren't simple, well-engineered analog tools so satisfying?
That's so cool. Like mathematical primitive archeology. The history of these sorts of analog computing devices that physically encode non-linear mathematical relations is fascinating.
With much tutoring, I learned to use a sextant and doing that gives one some sense of the "sorcery" and power achievable with blue-water navigation.
Boyer and Merzbach cover some of the development of these tools in their "History of Mathematics". Highly recommended.
i'm just not a serious enough cook, my kitchen's temperature varies humidity too the water coming out of the tap is random too so I just gave up at the end. Nowadays I read couple of recipes to get the gist of it, define the theme in my head and just go to town... I almost never have all the ingredients, so I substitute at will. I guess one instrument that I still use regularly is my Thermapen, food safety calls for one; and family feels more reassured when they see chicken breast that is ever so slightly pink but the temp reading suggests it's safe lol
This is great! I actually just bought a slide rule a few weeks ago (a Pickett N902-ES), and I've been working through the original booklet. One reason I bought it was to get a different perspective on calculation, since I never used a slide rule in school. Case in point: I do a lot of cooking, and this use case never occurred to me.
I don't see how a slide rule would substantially improve anything in my kitchen, honestly.
> Bakers understand the importance of proportions in cooking; they even write their recipes normalised to the weight of flour, meaning all other ingredients are given in proportion to the amount of flour.
I do more baking than cooking. Baker's math is an incredibly useful concept. But that math is trivial to do in my head, and that's much more convenient than a slide rule or other calculating device.
I have created a python program for exactly that purpose. Its nothing fancy. A yaml file of ingredients, another yamk fole of recipes and a yaml file for nutrient target and then some optimizers and some constaimt enforcers. I can now decide what I want to eat that day and the program tells me what quantity I should eat, what ingredients I need, what ingredient I need to buy, how much time it will take for cooking and how much meal prep boxes etc
Extremely helpful for weight loss
Only in Imperial/United States customary units. They start with a few unconvincing metric examples, then throw away the pretence and jump right into cups, tbsp, etc.
If you'd stop using Imperial, and started using metric + scales, the entire problem domain no longer exists.
Bases for cases. One of the advantages of Imperial measurements is that they are divisible by more factors than 2 and 5. This is where metric falls down for cooking. NB: I know the metric system and use it daily, but it's not perfect for every use case.
Yes but the packing density of flour varies cup to cup, within the same measuring cup, resulting in different amounts of flour.
> J. Kenji Lopez-Alt, the managing editor of the blog Serious Eats, once asked 10 people to measure a cup of all-purpose flour into a bowl. When the cooks were done, Mr. Lopez-Alt weighed each bowl. “Depending on how strong you are or your scooping method, I found that a 'cup of flour’ could be anywhere from 4 to 6 ounces,” he said. That’s a significant difference: one cook might be making a cake with one-and-a-half times as much flour as another.
So you have to carefully scoop precisely the same way every time to even be close to accurate??
One of the major problems with this theory is that "cup" doesn't have any standard definition - and measuring scoops marked as "1 cup" - can be anywhere (ignoring outliers) from 240, 236.6 or 227 ml. So - ignoring the fact that when you scoop flour - the same scooped "cup" can vary by as much as 10-15%, the cup itself may be off by 6%. And you are never quite sure which cup the original recipe maker was using.
This is why any half-ways sane baker works off a scale.
I think the argument is that commercial recipes in the US are written in proportional notation, e.g. 1:2:3 sourdough, but recipes in countries which use metric give units, e.g. 1kg:2L:3kg. I also note that if you add small proportions of an ingredient, e.g. salt, it might be easier to change units in metric (5g salt) while it would be easier to write proportionally in imperial (0.005 parts salt) if you were then going to scale to to a tonne/ton of dough.
I have no idea if this is true but it sounds like a coherent argument that isn't just volumetric vs mass units.
Very cool, I've never used a slide ruler but I can see how in logarithmic space, that 3.3/2 scaling factor simply becomes a distance you add.
Makes me want to get one now, because I like the concept of memorizing ratios rather than recipes (thanks to the popular eponymous book), and this seems more convenient (and satisfying) for non-trivial computations than getting my screen dirty or dictating it to an assistant.
Professional chefs recipes are all in proportions to begin with. For example for a baker everything else in a recipe is in proportion to the weight of the flour.
> I just found myself in someone else’s kitchen and they didn’t have a slide rule.
What? No way that happened! In all seriousness though I almost never find myself in the need to multiply anything in the recipe by the amount different than some multiple of 0.5 and these are pretty easy to do in my head.
As a hobbyist cook, this article starts with a false (or at least misleading) premise:
maybe the recipe calls for 80 g of butter but you only have 57 g
The amount of fat is rarely critical, pie crusts and puff pastry the exceptions. Unless the situation is puff pastry, make the full recipe. There are also recipes, like Better Homes and Gardens cookbook "baked rice pudding", that you can fudge ingredients to an extent, but can't double. The heat transfer of a double sized batch of custard prevents the whole thing from cooking.
The point being that food is more and less than chemistry. It's more and less than thermodynamics or heat transfer. It's art.
PS
I own 2 slide rules. I don't use either one in the kitchen.
Truth. To be blunt, while some aspects of some recipes can be scaled linearly, others can not.
Bakers percentages (measuring by-weight as a percentage of the largest mass ingredient (usually flour or water)) only work for lean dough and only for the non-fermenting components of that dough.
Put more concretely, one does not linearly scale the yeast in a lean dough. It results in far too rapid a fermentation, over-proofed dough, and less flavor complexity.
I think I own three. My grandfathers, my father's, and a cheap one I picked up at a garage sale as a kid.
I'd never put them near my kitchen - too precious. Also, not necessary? Today I readjusted the measurements for a chemistry experiment by 50% without a calculation aid and it's really not that hard.
i believe i threw a slide ruler in the trash recently. i stopped reading as soon as they said something about a c position. i’d rather have a digital scale- so many fewer measuring cups/spoons used, just do the addition in your head or tare as you add additional ingredients.
Also, not all ingredients in a recipe scale linearly--most notably spices, tinctures, and any fermentation components.
Is punching a number into a calculator and then multiplying by M (memory function, for the scale factor) really that much work than carefully sliding tithe slider into position and reading/eyeballing the output?
Evaporation is more about the water surface area and not the total volume, so a fixed depth above the rice is used for estimation. HN discussion on the physics: https://news.ycombinator.com/item?id=24021195
People had to be taught not to go wild with the extra precision.
https://sliderulemuseum.com/
Last year I picked up a bamboo Hemi and worked through the (70yo!) workbook. The trigonometric scales are cool. Making a single slide to find all the sides of a triangle is surprisingly satisfying. It got me to realize that, sliderules with the right scales can solve the roots of any 3-variable equation. I guess this is why there was a proliferation of industry-specific sliderules back in the day.
More generally, aren't simple, well-engineered analog tools so satisfying?
With much tutoring, I learned to use a sextant and doing that gives one some sense of the "sorcery" and power achievable with blue-water navigation.
Boyer and Merzbach cover some of the development of these tools in their "History of Mathematics". Highly recommended.
> Bakers understand the importance of proportions in cooking; they even write their recipes normalised to the weight of flour, meaning all other ingredients are given in proportion to the amount of flour.
I do more baking than cooking. Baker's math is an incredibly useful concept. But that math is trivial to do in my head, and that's much more convenient than a slide rule or other calculating device.
Only in Imperial/United States customary units. They start with a few unconvincing metric examples, then throw away the pretence and jump right into cups, tbsp, etc.
If you'd stop using Imperial, and started using metric + scales, the entire problem domain no longer exists.
In metric countries, a small kitchen scale is very common. The US seems to run on volume, rather than weight.
Baking is based on proportions. As long as you use the same measuring tool, the details don’t matter.
2 cups of flour works regardless of the size of your cup
> J. Kenji Lopez-Alt, the managing editor of the blog Serious Eats, once asked 10 people to measure a cup of all-purpose flour into a bowl. When the cooks were done, Mr. Lopez-Alt weighed each bowl. “Depending on how strong you are or your scooping method, I found that a 'cup of flour’ could be anywhere from 4 to 6 ounces,” he said. That’s a significant difference: one cook might be making a cake with one-and-a-half times as much flour as another.
So you have to carefully scoop precisely the same way every time to even be close to accurate??
This is why any half-ways sane baker works off a scale.
Anyway, it's not really an issue.
I have no idea if this is true but it sounds like a coherent argument that isn't just volumetric vs mass units.
Makes me want to get one now, because I like the concept of memorizing ratios rather than recipes (thanks to the popular eponymous book), and this seems more convenient (and satisfying) for non-trivial computations than getting my screen dirty or dictating it to an assistant.
What? No way that happened! In all seriousness though I almost never find myself in the need to multiply anything in the recipe by the amount different than some multiple of 0.5 and these are pretty easy to do in my head.
https://www.sliderule.tokyo/products/list.php
Circular rules are superior to slide rules.
maybe the recipe calls for 80 g of butter but you only have 57 g
The amount of fat is rarely critical, pie crusts and puff pastry the exceptions. Unless the situation is puff pastry, make the full recipe. There are also recipes, like Better Homes and Gardens cookbook "baked rice pudding", that you can fudge ingredients to an extent, but can't double. The heat transfer of a double sized batch of custard prevents the whole thing from cooking.
The point being that food is more and less than chemistry. It's more and less than thermodynamics or heat transfer. It's art.
PS
I own 2 slide rules. I don't use either one in the kitchen.
Bakers percentages (measuring by-weight as a percentage of the largest mass ingredient (usually flour or water)) only work for lean dough and only for the non-fermenting components of that dough.
Put more concretely, one does not linearly scale the yeast in a lean dough. It results in far too rapid a fermentation, over-proofed dough, and less flavor complexity.
I'd never put them near my kitchen - too precious. Also, not necessary? Today I readjusted the measurements for a chemistry experiment by 50% without a calculation aid and it's really not that hard.