9 ms·

You need a kitchen slide rule

67 points by aebtebeten 9mo ago

JohnFen 9mo ago
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.
- giraffe_lady 9mo ago
  Also nearly all western baking involves whole eggs, which you must treat as a unit unless you're doing just terrible volume. You can figure out the "base" (one egg) proportion and then just scale by integers of that.
  - orbital-decay 9mo ago
    Eggs are very different in weight, so you also need to specify the size grade
bediger4000 9mo ago
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.
- calmbonsai 9mo ago
  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.
  - D-Machine 9mo ago
    This. Belief in linear scaling of recipes is such a quick tell for someone who hasn't done even the most basic home cooking (or someone who has no sense of taste / texture at all).
    - TeMPOraL 9mo ago
      FWIW, in theory this makes slide rules even better for this, as they've been specifically designed to allow you to lock in non-linear relationships. Cooking is stacking exponents with whole range of parameters, so linear scaling indeed happens only sometimes, if you squint hard :). Unfortunately, the error bars on everything are huge - purity and quantity of ingredients, accuracy of measuring devices, accuracy and reliability of equipment, and people's care about the process - they're all so bad that cooking simply cannot be anything better than an art. (The non-art variant is called process engineering.)
      - D-Machine 9mo ago
        Heh, true, good point. But yeah, it is the messiness and art of it that keeps it fun for me (especially after a day of math and coding)!
- rngfnby 9mo ago
  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.
gorpy7 9mo ago
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.
efskap 9mo ago
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.
anArbitraryOne 9mo ago
I improved everything by converting to metric first if the recipe happens to be otherwise, and using metric measuring tools
zahlman 9mo ago
I've done quite a bit of math in my head in the kitchen....
Animats 9mo ago
And metric containers and recipes. In metric countries, a small kitchen scale is very common. The US seems to run on volume, rather than weight.
- Swizec 9mo ago
  > 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
  - eutropia 9mo ago
    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??
    - s5300 9mo ago
      [dead]
    - t-3 9mo ago
      You'll know if you need to add more flour when it comes time to knead. There's no such thing as accuracy in cooking, and especially not baking.
      - D-Machine 9mo ago
        Baking--along with fermentation, curing, and certain brines or other solutions--is the subset of cooking where accuracy of the masses of ingredients matters more than most others. And yet still you are right you must often adjust significantly in baking for other factors (temperature + yeast activity, humidity, flour grind and composition, and general feel on kneading).
calmbonsai 9mo ago
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.
- mynegation 9mo ago
  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.
  - deleted 9mo ago
    [deleted]
  - D-Machine 9mo ago
    In general seasoning (or saucing) anything solid is more about exposed surface area than mass, and this depends on things like cut sizes, evaporation shrinking, and god knows what other factors. It doesn't scale with simple math, because there are all sorts of other factors involved that complicate this (surface texture just being one). It is also all moot because ingredients (especially spices) have massive variance in potency, sweetness, bitterness, sourness, etc., so recipes are only ever a guideline. I.e. if you double a spice that is twice / half as potent as expected, you can get an unpalatable / bland dish, and IMO factors between 0.25 to 4.00 are extremely common for plenty of ingredients. So you always just need to taste and adjust accordingly. This is also ignoring that certain ingredients can vary in multiple dimensions (e.g. a lemon that is a lot sweeter than expected but less sour, and so simple scaling of the lemon alone can't get you want want: you need to reach for white sugar and/or citric acid to get your desired pH and sweetness). It is also a fantasy that all flavour concentrations are perceived linearly anyway (and this is especially the case for acidity / sour / pH generally, but also spiciness in e.g. ginger, pepper, capsaicin).
- paulmooreparks 9mo ago
  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.
alliao 9mo ago
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
- deleted 9mo ago
  [deleted]
Someone1234 9mo ago
> Kitchen work is all about proportions 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.
- aidenn0 9mo ago
  TIL that you never double a recipe when using metric units...
- paulmooreparks 9mo ago
  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.
- t-3 9mo ago
  Scales are fine, but you're going to need scoops anyway. However, once you've made a recipe before, you probably won't need the scale to make it a second time. Volume measuring equipment is useful for more than measurement, can be easily multiplied or halved, never needs calibration, charging or changing of batteries, and you're going to be estimating anyway once you've gotten familiar with a recipe. It's also very easy to estimate without any standard measuring equipment at all.
  - D-Machine 9mo ago
    > you're going to be estimating anyway once you've gotten familiar with a recipe I would disagree slightly for this when it comes to making precise doughs or other things like brines, syrups, candy, and etc. Or at least I would change "estimating" to "adjusting" in your statement above. When it comes to trying something new (whether in baking from a proper source, like e.g. Modernist Bread or Modernist Pizza, or otherwise), a scale is invaluable. But yeah, once you have some something a few times and have the feel, you can convert to volumes and go based on your senses. There's a baseline science / formula to some cooking, but the rest really is art. This feels like a nit, because really I am just glad to see someone else pointing out the obvious realities here. While I would be hesitant to try Mr. Slide Rule's cooking, I'd try your cooking without fear!
xelxebar 9mo ago
The Slide Rule Museum tickles hard some 2000's web nostalgia: https://sliderulemuseum.com/ 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?
- calmbonsai 9mo ago
  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.
jhbadger 9mo ago
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.
mynegation 9mo ago
> 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.
paulmooreparks 9mo ago
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.
- kqr 9mo ago
  If your goal is a different perspective on calculation, I warmly recommend learning mental maths with logarithms too. Not only does it complement slide rule practise, but it also gives you a linear/additive understanding of multiplication/powers which is useful. I don't understand complex numbers and time--frequency domain translations but I suspect a log understanding feels similar to those. https://entropicthoughts.com/learning-some-logarithms https://entropicthoughts.com/learning-some-logarithms
SoftTalker 9mo ago
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.
trueismywork 9mo ago
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
waynesonfire 9mo ago
I picked up a couple Concise circular rules made in japan a while ago. They're wonderful. I'll toss one in the kitchen. https://www.sliderule.tokyo/products/list.php https://www.sliderule.tokyo/products/list.php Circular rules are superior to slide rules.
Isamu 9mo ago
Yeah I remember my class was the last in our high school to learn the slide rule, the next year we transitioned to (expensive!) calculators. People had to be taught not to go wild with the extra precision.
anon84873628 9mo ago
Please, if you want good pesto, worry less about the ratios, and use real Parmiggiano Reggiano instead of "parmesan".
- kqr 9mo ago
  I live in Europe. When we say "parmesan" we almost always mean real Parmigiano Reggiano, and sometimes, in emergencies, Grana Padano.
deleted 9mo ago
[deleted]
D-Machine 9mo ago
As another commenter noted, few things in cooking actually scale linearly, and, in general, if you are following recipes mechanically like this, you produce sub-par results. You always have to adjust quantities for ingredient freshness, humidity, ingredient variance, and other variables, so recipes are only ever guidelines at best. And seasoning is always to taste (your own, and whomever you are cooking for) anyway. But, sure, I guess this helps you scale up those guidelines in some rare cases where that math isn't trivial to do in your head...
zdc1 9mo ago
What I would actually like in every kitchen is a scale and a lookup table for the weight of a cup of flour, cup of rice, mL of oil, etc. No more volume based measurements.
- D-Machine 9mo ago
  This is impossible for most ingredients because many ingredients (flour, oil, or almost all such ingredients) vary considerably depending on packing, composition, and a whole host of other factors, and, also, not all recipes need to be scaled by mass. If you see a recipe involving flour and it uses volume, it is trash, will not be reproducible. All serious baking is done by mass and mass only, except for glazes / coatings and/or if a very specific product / brand is specified. EDIT: as another commenter here noted, yeast also does not scale linearly (obviously) except in special cases. Also, oils in general should be measured neither by volume nor by mass, but relative to what they need to coat / submerge (be that an ingredient, a cooking surface, or some combination of the two), or, for deep-frying, based on the amount needed to not drop temperature too significantly for whatever batch you are frying. That is, much cooking is about surface areas of your ingredients.
culebron21 9mo ago
I think such scaling as the author suggests, can be done in the head. 57g is roughy 3/4 of 80g. It's trivial to take 3/4 of almost anything. 250g -> ~180..185g, 40 -> 30, 50 -> 37g. Unless you do bakery, where proportions are very important, there's no need for 3 digit precision. And yes, in general a slide ruler is a great tool. I should try it again.
deleted 9mo ago
[deleted]
saaaaaam 9mo ago
How can you measure basil leaves in cups? Is that “put the leaves in the cup” or “put the leaves in the cup and press them down” or “roughly chop the basil leaves and put them into the cup” or “finely chop the basil leaves and put them into a cup”? Using a slide rule is all very well, but you only really need it if you’re using daft measurements like cups and spoons. If you just use grams and millilitres you don’t need one.
- randerson 9mo ago
  Even 1 teaspoon of salt can be twice as salty as the recipe's writer intended. e.g. Morton's has denser flakes which are 1.8x as salty by volume compared to Diamond Crystal. For baking where its almost an exact science, it baffles me why recipes still use cups and spoons. I specifically search for recipes where the measurements are in grams. SeriousEats is often where I end up.
  - D-Machine 9mo ago
    SeriousEats is great most of the time, and if you can "acquire" copies of any of the Modernist series (Modernist Cuisine, Modernist Cuisine at Home, Modernist Bread, Modernist Pizza), those are all done by mass with baker's percentages.
- rekabis 9mo ago
  And then there is flour, which when measured by volume can exhibit massive differences in actual amounts depending on how packed said flour is. Which is why you can easily tell the difference between an expert baker and an idiot by whether they - respectively - measure flour by weight or by volume.
  - saaaaaam 9mo ago
    “expert baker and an idiot” Not pulling your punches there! :)
zkmon 9mo ago
When I was in college, a friend gifted me with a old slide rule (German make), but it was missing the slider scale. I created that slider by cutting a stripe out of my plastic shoe box. Worked like a charm. I think Slide rule is an amazing invention, for it's simplicity and vastness of calculations that can be done.
Xmd5a 9mo ago
But then he ruins everything by using volumetric units (don't even get me started on these units, let's just focus on volume). Indicating proportions with respect to weight is much simpler. Just put a scale under your mixing bowl and weight stuff as you add them. Less stuff to clean, less waste, easier to dose.

67 points by aebtebeten 9mo ago

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.

giraffe_lady 9mo ago
Also nearly all western baking involves whole eggs, which you must treat as a unit unless you're doing just terrible volume. You can figure out the "base" (one egg) proportion and then just scale by integers of that.
- orbital-decay 9mo ago
  Eggs are very different in weight, so you also need to specify the size grade

bediger4000 9mo ago

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.

calmbonsai 9mo ago
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.
- D-Machine 9mo ago
  This. Belief in linear scaling of recipes is such a quick tell for someone who hasn't done even the most basic home cooking (or someone who has no sense of taste / texture at all).
  - TeMPOraL 9mo ago
    FWIW, in theory this makes slide rules even better for this, as they've been specifically designed to allow you to lock in non-linear relationships. Cooking is stacking exponents with whole range of parameters, so linear scaling indeed happens only sometimes, if you squint hard :). Unfortunately, the error bars on everything are huge - purity and quantity of ingredients, accuracy of measuring devices, accuracy and reliability of equipment, and people's care about the process - they're all so bad that cooking simply cannot be anything better than an art. (The non-art variant is called process engineering.)
    - D-Machine 9mo ago
      Heh, true, good point. But yeah, it is the messiness and art of it that keeps it fun for me (especially after a day of math and coding)!
rngfnby 9mo ago
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.

gorpy7 9mo ago

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.

efskap 9mo ago

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.

anArbitraryOne 9mo ago

I improved everything by converting to metric first if the recipe happens to be otherwise, and using metric measuring tools

zahlman 9mo ago

I've done quite a bit of math in my head in the kitchen....

Animats 9mo ago

And metric containers and recipes. In metric countries, a small kitchen scale is very common. The US seems to run on volume, rather than weight.

Swizec 9mo ago
> 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
- eutropia 9mo ago
  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??
  - s5300 9mo ago
    [dead]
  - t-3 9mo ago
    You'll know if you need to add more flour when it comes time to knead. There's no such thing as accuracy in cooking, and especially not baking.
    - D-Machine 9mo ago
      Baking--along with fermentation, curing, and certain brines or other solutions--is the subset of cooking where accuracy of the masses of ingredients matters more than most others. And yet still you are right you must often adjust significantly in baking for other factors (temperature + yeast activity, humidity, flour grind and composition, and general feel on kneading).

calmbonsai 9mo ago

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.

mynegation 9mo ago
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.
- deleted 9mo ago
  [deleted]
- D-Machine 9mo ago
  In general seasoning (or saucing) anything solid is more about exposed surface area than mass, and this depends on things like cut sizes, evaporation shrinking, and god knows what other factors. It doesn't scale with simple math, because there are all sorts of other factors involved that complicate this (surface texture just being one). It is also all moot because ingredients (especially spices) have massive variance in potency, sweetness, bitterness, sourness, etc., so recipes are only ever a guideline. I.e. if you double a spice that is twice / half as potent as expected, you can get an unpalatable / bland dish, and IMO factors between 0.25 to 4.00 are extremely common for plenty of ingredients. So you always just need to taste and adjust accordingly. This is also ignoring that certain ingredients can vary in multiple dimensions (e.g. a lemon that is a lot sweeter than expected but less sour, and so simple scaling of the lemon alone can't get you want want: you need to reach for white sugar and/or citric acid to get your desired pH and sweetness). It is also a fantasy that all flavour concentrations are perceived linearly anyway (and this is especially the case for acidity / sour / pH generally, but also spiciness in e.g. ginger, pepper, capsaicin).
paulmooreparks 9mo ago
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.

alliao 9mo ago

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

deleted 9mo ago
[deleted]

Someone1234 9mo ago

> Kitchen work is all about proportions 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.

aidenn0 9mo ago
TIL that you never double a recipe when using metric units...
paulmooreparks 9mo ago
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.
t-3 9mo ago
Scales are fine, but you're going to need scoops anyway. However, once you've made a recipe before, you probably won't need the scale to make it a second time. Volume measuring equipment is useful for more than measurement, can be easily multiplied or halved, never needs calibration, charging or changing of batteries, and you're going to be estimating anyway once you've gotten familiar with a recipe. It's also very easy to estimate without any standard measuring equipment at all.
- D-Machine 9mo ago
  > you're going to be estimating anyway once you've gotten familiar with a recipe I would disagree slightly for this when it comes to making precise doughs or other things like brines, syrups, candy, and etc. Or at least I would change "estimating" to "adjusting" in your statement above. When it comes to trying something new (whether in baking from a proper source, like e.g. Modernist Bread or Modernist Pizza, or otherwise), a scale is invaluable. But yeah, once you have some something a few times and have the feel, you can convert to volumes and go based on your senses. There's a baseline science / formula to some cooking, but the rest really is art. This feels like a nit, because really I am just glad to see someone else pointing out the obvious realities here. While I would be hesitant to try Mr. Slide Rule's cooking, I'd try your cooking without fear!

xelxebar 9mo ago

The Slide Rule Museum tickles hard some 2000's web nostalgia: https://sliderulemuseum.com/ 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?

calmbonsai 9mo ago
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.

jhbadger 9mo ago

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.

mynegation 9mo ago

> 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.

paulmooreparks 9mo ago

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.

kqr 9mo ago
If your goal is a different perspective on calculation, I warmly recommend learning mental maths with logarithms too. Not only does it complement slide rule practise, but it also gives you a linear/additive understanding of multiplication/powers which is useful. I don't understand complex numbers and time--frequency domain translations but I suspect a log understanding feels similar to those. https://entropicthoughts.com/learning-some-logarithms https://entropicthoughts.com/learning-some-logarithms

SoftTalker 9mo ago

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.

trueismywork 9mo ago

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

waynesonfire 9mo ago

I picked up a couple Concise circular rules made in japan a while ago. They're wonderful. I'll toss one in the kitchen. https://www.sliderule.tokyo/products/list.php https://www.sliderule.tokyo/products/list.php Circular rules are superior to slide rules.

Isamu 9mo ago

Yeah I remember my class was the last in our high school to learn the slide rule, the next year we transitioned to (expensive!) calculators. People had to be taught not to go wild with the extra precision.

anon84873628 9mo ago

Please, if you want good pesto, worry less about the ratios, and use real Parmiggiano Reggiano instead of "parmesan".

kqr 9mo ago
I live in Europe. When we say "parmesan" we almost always mean real Parmigiano Reggiano, and sometimes, in emergencies, Grana Padano.

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D-Machine 9mo ago

As another commenter noted, few things in cooking actually scale linearly, and, in general, if you are following recipes mechanically like this, you produce sub-par results. You always have to adjust quantities for ingredient freshness, humidity, ingredient variance, and other variables, so recipes are only ever guidelines at best. And seasoning is always to taste (your own, and whomever you are cooking for) anyway. But, sure, I guess this helps you scale up those guidelines in some rare cases where that math isn't trivial to do in your head...

zdc1 9mo ago

What I would actually like in every kitchen is a scale and a lookup table for the weight of a cup of flour, cup of rice, mL of oil, etc. No more volume based measurements.

D-Machine 9mo ago
This is impossible for most ingredients because many ingredients (flour, oil, or almost all such ingredients) vary considerably depending on packing, composition, and a whole host of other factors, and, also, not all recipes need to be scaled by mass. If you see a recipe involving flour and it uses volume, it is trash, will not be reproducible. All serious baking is done by mass and mass only, except for glazes / coatings and/or if a very specific product / brand is specified. EDIT: as another commenter here noted, yeast also does not scale linearly (obviously) except in special cases. Also, oils in general should be measured neither by volume nor by mass, but relative to what they need to coat / submerge (be that an ingredient, a cooking surface, or some combination of the two), or, for deep-frying, based on the amount needed to not drop temperature too significantly for whatever batch you are frying. That is, much cooking is about surface areas of your ingredients.

culebron21 9mo ago

I think such scaling as the author suggests, can be done in the head. 57g is roughy 3/4 of 80g. It's trivial to take 3/4 of almost anything. 250g -> ~180..185g, 40 -> 30, 50 -> 37g. Unless you do bakery, where proportions are very important, there's no need for 3 digit precision. And yes, in general a slide ruler is a great tool. I should try it again.

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saaaaaam 9mo ago

How can you measure basil leaves in cups? Is that “put the leaves in the cup” or “put the leaves in the cup and press them down” or “roughly chop the basil leaves and put them into the cup” or “finely chop the basil leaves and put them into a cup”? Using a slide rule is all very well, but you only really need it if you’re using daft measurements like cups and spoons. If you just use grams and millilitres you don’t need one.

randerson 9mo ago
Even 1 teaspoon of salt can be twice as salty as the recipe's writer intended. e.g. Morton's has denser flakes which are 1.8x as salty by volume compared to Diamond Crystal. For baking where its almost an exact science, it baffles me why recipes still use cups and spoons. I specifically search for recipes where the measurements are in grams. SeriousEats is often where I end up.
- D-Machine 9mo ago
  SeriousEats is great most of the time, and if you can "acquire" copies of any of the Modernist series (Modernist Cuisine, Modernist Cuisine at Home, Modernist Bread, Modernist Pizza), those are all done by mass with baker's percentages.
rekabis 9mo ago
And then there is flour, which when measured by volume can exhibit massive differences in actual amounts depending on how packed said flour is. Which is why you can easily tell the difference between an expert baker and an idiot by whether they - respectively - measure flour by weight or by volume.
- saaaaaam 9mo ago
  “expert baker and an idiot” Not pulling your punches there! :)

zkmon 9mo ago

When I was in college, a friend gifted me with a old slide rule (German make), but it was missing the slider scale. I created that slider by cutting a stripe out of my plastic shoe box. Worked like a charm. I think Slide rule is an amazing invention, for it's simplicity and vastness of calculations that can be done.

Xmd5a 9mo ago

But then he ruins everything by using volumetric units (don't even get me started on these units, let's just focus on volume). Indicating proportions with respect to weight is much simpler. Just put a scale under your mixing bowl and weight stuff as you add them. Less stuff to clean, less waste, easier to dose.