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Mar 21, 2014 08:17 AM

How accurate is too accurate and using laboratory glassware in the kitchen

With all of the controversy over soda-lime glass in Pyrex glassware, I am making the choice of searching for suitable borosilicate glass replacements. This includes liquid measuring cups. Rather than getting old, used pre-90s Pyrex, Im thinking laboratory glassware would be great and cool looking in my kitchen. Yes, they use mL but fortunately, 1/4 cup is approximately 60 mL, 1/3 cup is approximately 80 mL and so on and so forth so that is easily remedied. For baking applications, we all know about how significant accuracy is. Yet many baking books still do not include weights in their recipes so it can be hard to avoid measuring cups. Unfortunately, even in laboratory glassware, even beakers aren't completely accurate with Schott Duran (arguably the highest quality laboratory glassware) indicating an accuracy of +/-10%.

The ideal measuring tool would be a volumetric flask followed by a measuring cylinder. These two, however, would necessitate the use of a funnel due to their narrow openings. It seems that what you gain in accuracy, you lose in practicality. How accurate is too accurate? Would a volumetric flask/cylinder lead have a noticeable difference on the final product? Granted, most cookbook authors probably never wrote down their recipes to such a degree of accuracy but that still leaves the notion of replicating the same results consistently. I realize this is completely unnecessary but if im likely to be stuck with it for years and years, might as well put some thought into it.

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  1. I'm not particularly knowledgeable about this but it sounds like you want to use it for measuring not cooking in. Why wouldn't Pyrex or anything else for that matter work just fine?

    5 Replies
    1. re: c oliver

      Even plastic would work fine but the fact that they switched to a lower quality material is just disheartening. They dont make things like they used to. I've seen Julia Child use her Pyrex measuring cup in the oven and so has Jacques Pepin. Now you cant do that without the risk of the glass exploding. There are times when I would like to heat liquids directly in the measuring cup as well. I only like to buy quality products, even avoiding "Made in China at all costs".. God, I even made sure my pen was made of celluloid as opposed to precious resin or other plastics lol. If soda-lime glass means lower quality, I'll avoid it.

      Plus, im sure the accuracy of lab tools have been tested more rigorously. Even my All Clad dry measuring cups are off. Sure most cups would work fine but why settle for second best? Its a tiny investment regardless.

      1. re: ElPsyCongroo

        I think heating something in a measuring cup will decrease accuracy, esp. since you seem to want an extreme amount of it. You will get some evaporation. I heat an approx. amount and then measure. BTW there are many quality products that are made in China. I would throw out the baby with the bath water.

        As others here have said, the degree of accuracy, even when baking, isn't as great as you seem to think it is. What do you make the most?

        1. re: c oliver

          Less things to wash is always a good thing. :)I do take evaporation into account. Hard to say what I cook most as im always trying to seek new things to make. Variety is the spice of life.

          and true some things Made in China are good but im not one to take that gamble.

          As others have said, it is best to weigh but when I dont have luxury to access metric conversions online for different ingredients, its great to have this as a good standby.

          When I choose what to buy for my kitchen, I like to ask myself....How effective it is as a tool (in this case it would be its accuracy) And how is the quality of the material and construction? How easily will it break and will it last me? I guess thats why im being so anal and OCD about this. So forgive me for going a little crazy over this haha. :P

        2. re: ElPsyCongroo

          I dispense directly from my hot water pot set at 208 f into pyrex all the time without any problems.

          1. re: rasputina

            And I pour from my simmering pot through a sieve directly into my Pyrex measuring cups.

      2. Have a link that details said "controversy?" I googled and couldn't find anything especially controversial. Actually...

        "lime-soda glass is mechanically stronger and more temperature shock resistant . Also, it breaks into smaller, less dangerous shards"

        So what's the big deal?

        Too accurate? No such thing. Rather you should ask, "how much accuracy is NECESSARY?" And the answer is, "not much." IMO there are so many factors affecting the outcome in a home kitchen that a minor over or under on a liquid measurement is the least of your worries... Just get something you can work with and learn to adjust on the fly.

        2 Replies
        1. re: davis_sq_pro

          That was the same argument that Pyrex used. What you've quoted was by the manufacturer, Anchor Hocking, who has also switched to lime-glass and we all know how manufacturers love telling the truth. Lime glass is actually cheaper to use and is probably the main reason why they switched. There is a reason why borosilicate is used in laboratory glassware. Pyrex's lab glassware is still borosilicate which clearly shows which they feel is the superior material. That statement on thermal shock resistance is actually false. It is the other way around as the thermal expansion coefficient of borosilicate is actually one third that of soda-lime glass. The only advantage soda-lime glass really has is in the way it breaks. Soda-lime glass will break into large , dull edged pieces whereas borosilicate will break into smaller and sharper pieces. That being said, that doesn't help much as both are probably equally as likely to break when falling off the countertop and will have to be replaced.

          There is even a full thread that was last on here a few days ago on Pyrex exploding:

          1. re: ElPsyCongroo

            So why do you have this concern for things to measure with rather than cook?

        2. Unless you are cooking crack you aren't going to achieve temperatures that will discount the use of soda-lime glass.

          3 Replies
          1. re: GraydonCarter

            If you are measuring only it won't matter. Cooking will. With soda lime glass if you create a 100F degree difference in the temperature of the glass, it is subject to shattering. If you remove something from a 350F oven this can easily happen if some parts of the glass cool quicker than others, especially with some of the large open handles some newer pieces have. Borosilicate glass will tolerate about 300F degrees in difference.

              1. re: c oliver

                Right. I prefaced with that but when you bring up cooking this comes into play. Some people heat ingredients as well after measuring.

          2. You are best off when you weigh your ingredients in any case. GourmetSleuth provides good, convenient conversions.

            1 Reply
            1. re: bcc

              I rarely bake but I when I make pasta I always weigh rather than measure. When measuring I use glass (Pyrex), plastic and metal. Not sure why OP is concerned as s/he references only measuring.

            2. I would trust the markings on the labware over the markings on the Pyrex. None of them are really accurate unless the vessel is placed on a level surface at eye level. The thicker Pyrex refracts the light a greater distance to the inside level of the item being measured, and this can make quite a difference depending upon how steep of an angle your are viewing the measuring marks. If you need better accuracy, use a scale.

              1 Reply
              1. re: NVJims


                I have some of these angled ones (down to a quarter cup) and some Pyrex etc.