Biology in Practice: How to Stretch a Gallon of Milk


Christopher Carr

Christopher Carr does stuff and writes about stuff.

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20 Responses

  1. Avatar dragonfrog says:

    For a thicker tzatziki, I grate the cucumber into a colander, stir in salt, then squeeze the liquid out after an hour or so. I also add lemon juice, which I guess thins it back out some.Report

  2. Avatar zic says:

    The whey is a great liquid to use in bread; use it in place of water or milk. I’m a big fan of powdered buttermilk for baking, and frequently use whey for the liquid in muffins and pancakes with some powdered buttermilk.

    And I’ve seen several recipes for salt-preserved pickles that call for a bit of whey.

    Nice, Christopher, Thank you.

    (Currently working on a sourdough bread, though without whey, didn’t have any on hand.)

    And frozen yogurt, if you’ve an ice-cream maker. I like it with just about 1/2 cup of maple syrup and some toasted pecans mixed in at the end. But a bit of vanilla and some fresh fruit or frozen is also nice. Without the ice cream maker, you can simply put it in a zip lock bag and freeze, take it out and kneed it after about 10 minutes and then every 5 or so until it’s set up, usually about 1/2 hour or so.Report

    • Avatar Christopher Carr in reply to zic says:

      I might give frozen yogurt a try this week. Cheers for that.Report

      • Avatar zic in reply to Christopher Carr says:

        I’ve never tried the bag method, my mom told me about it. A Google search shows several recipes using a large (gallon bag) with ice/salt, and a smaller (pint sized bag) with the ice cream, shaken for five minutes.

        I’m not an appliance fan, but the ice cream freezer, with inserts that go in the regular freezer, are nice to have around; particularly in summer when the wild berries are plentiful and begging to be turned into sorbet.

        Younger son insists a shot of brandy/rum helps prevent large ice crystals forming and improves flavor.Report

  3. Avatar Will H. says:

    That’s cool stuff.Report

    • Avatar Christopher Carr in reply to Will H. says:

      Thanks Will!Report

      • Avatar Will H. in reply to Christopher Carr says:

        Really, I was intrigued by your protocol #1. It’s a lot like mead-making.
        I’m strictly of the no-boil type. Boil the water, dump the honey in, and it comes out to somewhere in the neighborhood of 180. A good 10 to 20 minutes sterilizes it without the deterioration that comes with boiling.

        The difference is the pitching temp.
        I use a red wine yeast for mead (results from feedback in taste-testing). That type of yeast will work well in the 80 – 85 range, but I tend to go lower due my experiences with ales.
        With ales, you have to cool below 80 to aerate or you get oxidation. That comes from the reaction with the hop oils from what I gather, but I still cool below 80 to aerate a mead.

        125 is likely way too high for the strains of yeast that I work with. I have some sours that I cultured from bottles of Orval and Flag Porter that have other strains that tolerate higher temps. But I would still be leery of anything over 90.

        My understanding here is that 125 ensures the survival of the appropriate bugs for yogurt.Report

        • Avatar Christopher Carr in reply to Will H. says:

          Mead is actually next on my list! I’m planning on having a 12th Night party this year (seriously). Do you have a recipe or a good website to check out?

          You’re right that 185 is more than enough to kill everything. Boiling is overkill. After that dropping to 125 degrees assures that S. thermophilus and its cohorts the Lactobacilli will be okay when they’re mixed in. This combined with the hermetic seal pre-incubation means that there will not be any colonization by unwanted bugs, and our yogurt will be clean. And therefore ridiculously delicious.

          The human taste bud is a complex and nuanced machine, one that I would like to study more and more.Report

          • Avatar Will H. in reply to Christopher Carr says:

            Most mead recipes deal with spices or varietal honeys more than anything.
            Varietal honeys are nice, and these days I’d rather add the spices into a finished product than have a whole batch like that.

            First, you have to figure out how strong to make it. I started with 3lbs./1 gal., but that was too strong. I couldn’t stay awake long enough to enjoy it. I went down to 2.5lbs./1 gal.
            Somewhere after 3.5lbs./1 gal but before 4 lbs./1 gal., you’ll reach a point where the yeast dies off from the alcohol rather than continuing to ferment.
            I step my mead up to keep the gravity low. Anything over 1.060 will smush the yeast, inhibiting growth; and 1.070 is definitely way too high.
            I start it with from 5 to 7 lbs./3 gal., and let that sit for 6 weeks. I take the total honey weight, divide by two, and add them for a total of 1 gal. additional volume six weeks apart. Total 18 weeks.
            Mead doesn’t benefit from aging due to the lack of tannins.

            Other than that, what you need to know:
            3 lbs. of honey = 1 quart. Figure your total volume with this.
            Honey is deficient in magnesium, which the yeast need for healthy reproduction. About 3 grains of epsom salt is plenty. I always use filtered water, because that’s one of my hangups. Adding a gallon of unfiltered water should do just as well.
            Boiling the water reduces temporary hardness, but you’ll still need some acidification. Lemon juice is the way to go. Get some litmus paper, and make sure your stuff is sitting around 4.8 to 5.4.
            A paint stirrer on an electric drill for 2 minutes works great for aeration.

            Other than that, find a good yeast you like, and stick with it.
            I took a look, and I’ve used the White Labs wlp718 Avize and the wlp735 French White. At least, that’s what I can find. I was pretty sure that I had a red wine yeast in there.

            Those are the basics.Report

            • Avatar Will H. in reply to Will H. says:

              Sorry, but I realize that was unclear.
              It’s an initial and two additions.
              Each addition adds 1 gal. volume, so I end up with 5 gal. with about 12.5 lbs. of honey.Report

            • Avatar Will H. in reply to Will H. says:

              One other word about yeast metabolism and temperature:
              For every +10F, the yeast metabolism doubles.
              For every -10F, the yeast metabolism decreases by half.

              Moderate temps will produce esters, which can be fine, as long as they’re not overpowering (esters are really the big difference between a lager & an ale, btw).
              At higher temps, phenols become more pronounced. Some phenols give a spicy flavor, while others give a harsh flavor.
              A higher temps than that, fusels form. Fusels area bad in any amount.

              Which is to say, that the best fermentation temps are at the low end of the ester spectrum, in most cases.

              And if you want your mead stronger than the yeast will take, try cold distilling.
              Just freeze the stuff in a bowl and pull out the large chunks of ice.Report

          • Avatar Mike Schilling in reply to Christopher Carr says:

            I’m planning on having a 12th Night party

            Is that where the men have to dress up as women pretending to be men?Report

  4. Avatar Turgid Jacobian says:

    (I prefer fake Tupperware for real neufchatel and real Tupperware for fake neufchatel.)


  5. Avatar Rtod says:

    Oh man, this is amazing. Can I use any kind of milk? Goat, or even non-fat?Report

  6. Avatar p mac says:

    Or you can get lucky. Just found the most delicious wild mushrooms I’ve ever had, short of morels. Its a field mushroom (agaricus elvensis) found in Europe that looks enough like ordinary field mushrooms (agaricus campestris) that I took a chance and picked them.
    Extensive research ended up with: Edible choice.
    Lightly sautéed in butter, it smells like theatre popcorn. Tastes like heaven.Report

  7. Avatar Jason Kuznicki says:

    This was a fun post, and I liked it a lot. But I do have a quick question or two on lactose intolerance:

    The whey fraction of milk contains nearly all of the lactose found in whole milk. Whey is one of those avoid-at-all-costs food ingredients for the lactose intolerant. Sadly, it’s used in a whole lot of packaged food products.

    However, yogurt bacilli will very efficiently eat all of the lactose in a sample of milk, so it’s not clear to me whether the “whey” extracted here will still be bad. Is it? Does anyone know?

    When I make homemade paneer, I start with Lactaid milk, whose lactose has already been digested by the application of lactase enzyme. Paneer doesn’t use a bacterial culture, just milk, vinegar, and cheesecloth, so you can’t expect all the lactose to be removed any other way. (Or can you?)

    Blue cheese cultures excel at digesting lactose; others are usually poor, and non-blue cheese usually retains considerable lactose unless it has aged for several months. And sometimes even then it can be a problem.Report

  8. Avatar wardsmith says:

    Dude! Great stuff, and I’ll have to try some of these. Only recently has the wife gotten into tzatziki et al (Chinese are notoriously lactose intolerant and dairy averse). Your post reminded me of my own comment on the much-traveled Jason Op Ed. Back in the days when I was dirt poor, I too made my own yoghurt and could really stretch it out. If you’re really desperate (and poor) you could start with milk that’s already going sour (since it will end up as yoghurt anyway). I made friends with the assistant mgr at a nearby store and he’d give me gallons that were past their expiration date for free. Nowadays there is probably a law against that.

    Speaking of laws, Costco makes a mean broiled chicken. Part of the reason it is so good is because they rotate the entire stock every two hours. They used to just throw away the unsold chickens. I went to the manager and said, “Why don’t you donate all those rotisserie chickens to the food banks?” He said, “Can’t, health regulations would kill us, we’ve already looked into it”. I said it was a crime to throw all that away, and we noodled on it for awhile and decided that they could use that chicken in Caesar salads and fettuccine. Even though he was a mgr, it worked better by their system for me (a customer) to put it in their suggestion box as in “Gee it sure would be nice if you guys put that great rotisserie chicken into Caesar salads and other stuff so I don’t have to”.Report

  9. I never made fresh yogurt before but I might try it now. Thanks to this detailed instruction and the delicious recipes that we may try after, hopefully, successfully making our own yogurt. This is one healthy way to satisfy your cravings.Report