Sources of "recipe quality" hot water

Discussion in 'Pastries & Baking' started by Donut, Mar 22, 2019.

  1. Donut

    Donut

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    We are opening a small donut shop. We will need a source of "recipe quality" hot water for making the donut dough (raised donuts) and batter (cake donuts). A typical batch of raised donuts requires ~8.5 lbs of water (~1 gallon) that can range in temperature up to 90°F. (Water temperature for cake donuts can exceed 105°F.) We will be making multiple batches throughout the day.

    Some donut shops use an electric hot water dispenser (like used to heat water for coffee or tea) as a source of hot water for preparing the donut mix. However, this solution has several disadvantages:
    1. Requires counter space.
    2. No ability to use a water mixer/doser.
    3. Limited quantity of how water available at a time.
    4. Cost of the dispenser.
    Using a plumbed source of hot water would negate the first three disadvantages, and the overall costs would be reduced as well. Ideally, I would install a point-of-use (POU) tankless electric water heater just upstream of the mixer/doser. This would also allow us to install an activated carbon filtration system in the cold water supply just upstream of the POU heater. Unfortunately, the commercial space we'll be leasing only has 100A of electric service and a POU heater would draw at least 60A. Upgrading the electrical service to the shop is way outside our budget.

    The other option would be to use water from the tank-style water heater (which uses natural gas) already installed in the shop; this heater is like the typical water heater in most US homes. Normally, it's recommended to not consume hot water from a heated supply. This is mostly because of concerns of hot water causing more lead/chemicals to leach from pipes versus cold water. Certainly, this is a concern for plumbing installed prior to 1986, when copper pipes were joined with lead-based solder. Or for PEX pipe, which can leach more chemicals out of the plastic at high temperatures. But I would plumb the hot water pipe from the tank heater to the dough prep station using copper and lead-free solder. Also, the distance from the heater to the dough-prep station is very short and that pipe would also feed a nearby hand washing sink, so the hot water in the line would be constantly flushed throughout the workday. This would mean hot water flowing from the water heater to the dough-prep station would have very little dwell time in the pipes to leach anything.

    So the only real downside that I can see would be the inability to install an activated carbon filter on the hot water supply to the dough-prep station. However, the cold water supply to the dough-prep station will have carbon filtration so the final mixed-temp water for the dough will be partially carbon-filtered in proportion to the cold'/hot water ratio in use. And there will be a point-of-entry sediment filter for all the water coming into the shop, including the water supply to the tank water heater.

    Thoughts?
     
  2. Seoul Food

    Seoul Food

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    I think you are over thinking this. First off, I don't really understand what you are trying to say about plumbing a new copper line directly from the hot water tank. Doesn't you kitchen have any sinks already? It's all the same water, there is no need to plumb another line off of it. As for the copper, you don't need to solder anymore they have something called a shark bite that is just plug and play. If you already have a water filtration system in place on your main water line coming in from the street than the water going to your tank is already filtered and you wouldn't need one piped in after the water tank anyways. Unless you are in Ferguson I see no reason why you couldn't just use the water from the tap and heat it to the desired temperature or not. Plenty of people use tap water for baking and have no issues. Also getting lead poison from eating donuts is probably not the biggest health concern related to their ingestion. If you are still convinced the tap water will make that big of a difference buy some distilled water and make two batches and do a blind taste test. If no one can tell the difference then you have your answer.
     
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  3. Donut

    Donut

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    This is a new business in a new commercial space. We will be building the kitchen, installing sinks, etc.

    Shark Bite fittings are expensive. And given that they achieve their seal through the use of a rubber o-ring (which can harden and degrade over time), I don't entirely trust them to never leak compared to solder. Soldering copper pipe is a well-proven method of making permanent leak-free connections (provided the soldering was properly performed).

    Nothing is in place yet; this is all pre-planning. But the point-of-entry filtration is for particulate matter (sediment). Adding activated carbon filters on the water main (for removing things like chlorine) would be too restrictive on the flow rate. And quite expensive too.

    In my original post, I listed three reasons why I do not want to have to dispense cold water and then heat it. My goal is to use plumbed hot water, mainly so I can use a mixer/doser for dispensing the water for making the dough. Ideally, the plumbed water would be heated with an on-demand tankless POU heater. But I can't use that solution because it would put too great an ampacity demand on the limited electric service installed in the space we are leasing.

    Yes. But the conventional wisdom is to only use the cold water supply on the tap (as discussed above).

    I'm not concerned about "lead poisoning." But my goal is to offer donuts made from natural ingredients that do not have any chemical contamination. This is about quality, not simply taste.
     
  4. dueh

    dueh

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    Most water meters I have used generally have a temperature adjustment on them. They do however waste quite a bit of water adjusting to the desired temp prior to dosing.

    Tankless water heater maybe?
    I know this route is a bit more on the expensive side. So is the water meter.

    Instahot dispenser?
    plumb it right into your counter space and weigh water as you dispense? In line filter installed before it hits the heater?

    Maybe a large stock pot with a spigot?

    the batch size you are doing doesn't seem to be in need of most of these options though. I was thankful for having a water meter when mixing large batches of dough in the spiral mixer. Easily 10-15 kilo+ in water
     
  5. Seoul Food

    Seoul Food

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    I guess I'm just not understanding what you want entirely. Adding your carbon filter plumbed after the water tank but before the faucet would be possible. Also I'm not a professional baker so I'm not sure what you mean with the conventional wisdom with only using cold tap water. A on demand water heater is using the same tap water regardless of if you are heating it, or if you are using the water heated in a tank. All the water is the same coming from the main from the street and it isn't going to change the fact that using cold water from the tap or hot water from a tank or tankless system that is piped to a dispatching area is the same exact water. If you are only looking for a 90 - 105 F temperature range you can just set the thermostat on the tank. Most household water will exceed that temperature already. As for the shark bites, you didn't state originally that it was a complete build from the ground up which in that case it would obviously be much more economical to weld all the plumbing instead of using shark bites. Even so I do not imagine they will wear out in the time you are in the space. As for the lead factor you had brought that up yourself and that is the only reason I mentioned it. On another point I'm not sure what you are referring to about it not being recommended consuming water from a heated supply. This is how a lot of liquid coffee and drink machines work. Also, why would it be bad to drink water from a heated supply but okay to use it to make donuts? Finally if you are going to go through all of the trouble running plumbing to a dispenser and use one or more filtration systems it seems like it would be less economical to tie it into your hand washing sink.
     
  6. Donut

    Donut

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    Yes, the purpose of the mixer/doser is to mix cold and hot water to the set desired temperature (tempering), and then to dose out the correct volume of tempered water. It takes time for the water coming into the mixer/doser to reach steady temperatures, so some water will be bypassed to the drain until the set temperature is achieved and stable.

    I stated that the tankless water heater was my ideal solution for providing hot water at the dough prep station. However, electric tankless heaters require a considerable amount of electricity (we would need at least an 18kW heater). The commercial space we are leasing does not have enough electric amps available for us to add an electric tankless heater of that size. A gas-fired tankless heater would be impractical for this application.

    These types of heaters are designed for low flow and low volume: they dispense cups, not gallons. It is essentially a very small electric tank heater mounted under the sink deck. It would be insufficient for the amount of hot water we would need for making the dough.

    In my original post, I mentioned hot water dispensers and the disadvantages of using them for this purpose.
     
  7. Donut

    Donut

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    Two problems with this idea:
    1. Activated charcoal works like a chemical magnet: the chemical molecules stick to the surface of the carbon as the water flows past. But it works best with cold water. If you pass hot water over activated charcoal, the energetic hot water molecules can "knock" the chemical molecules off the surface of the carbon. If the charcoal is already "loaded" with chemicals (from earlier water passing over it), then hot water can cause the water to become more contaminated leaving the filter than what was in the water entering the filter.
    2. Water filters are typically made to withstand temperatures only up to 100°F.

    This has nothing to do with the baking profession. It's actually a warning to the general public to only use cold water from the faucet for drinking and cooking. This is because hot water sitting in your home's pipes can potentially leach harmful chemicals out of those pipes (because hot water is more corrosive than cold water).

    Yes, it's the same water supply. The difference is that cold water sitting in pipes is much less likely to leach out chemicals than hot water. So if you have an old house with copper pipes joined with lead-bearing solder, then hot water sitting in those pipes will leach out lead at a much greater rate than cold water. Likewise, if you have PEX piping then hot water sitting in the PEX is more likely to leach chemicals out of the plastic compared to cold water.

    The advantage of a POU tankless heater is that the hot water is not sitting in the pipes for extended periods of time. Instead, the water is heated only as it is being drawn from the faucet. And because POU tankless heaters are installed very close to the faucet (POU = Point-of-Use), the piping between the heater and the faucet is very short (e.g, a couple of feet, compared to possibly over 50 feet of piping between a tank hot water heater and a faucet).

    The point is to minimize the amount of time that hot water is in contact with your plumbing's pipes.

    Heating the water AFTER it leaves your plumbing is fine. That's because hot beverage machines are made with food-safe parts that will not leach lead/chemicals into the hot water. Same with heating water in a kettle or cooking pot. That's why it's recommended to start with cold water from the tap.

    The handwashing sink is downstream of the dough prep station (but not part of any filtration at the dough prep station). The advantage of having the handwashing station on the same piping is twofold:
    1. Each time someone washes their hands, it draws water out of those pipes. As mentioned earlier, the main problem with leaching is when water dwells in the piping for some period of time. The longer the water sits in the pipes, the more time it has to accumulate chemicals leaching out of the pipes. (this is true for both cold and hot water, but because hot water is much more corrosive than cold water, the hot water leaching is what we're concerned about). Each time water is used from a branch of piping, the "contaminated" water is flushed out and replaced with new "uncontaminated" water.
    2. Because we need hot water at the dough prep station, each time water is used at the handwashing sink, it draws newly heated water from the tank into the piping. So we will waste less water waiting for the hot water to come up to full temperature at the dough prep station.
     
  8. dueh

    dueh

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    So it sounds like you already know exactly what you want...
     
  9. Donut

    Donut

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    I was seeking feedback from other professionals, particularly those in the bakery business who have had to deal with sources of hot water for dough preparation.

    I assume (but don't know) that most regular restaurant kitchens that need hot water for cooking or meal preparation simply draw cold water from a faucet and heat it on the stove or use a hot water dispenser.
     
  10. halb

    halb

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    That would be correct. I don't think anybody is as "over the top" as you are about hot water.
     
  11. Vjan

    Vjan

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    Out of curiosity, how is this to warn the general public? How do you plan to let customers know?
    Will your counter staff explain this to all first time customers? Your customers will be going to your business to have delicious donuts, not to be told their water at home could harm them.
     
  12. halb

    halb

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    Instead of plying the internet (where I'm sure all this nonsense came from) he could have his water tested which would tell him exactly what the levels of lead and anything else are present. Lead has been banned from plumbing since the 80's and all solder used by plumbers (even on drain lines) by law must be lead free. Since this is a new build I just don't see the concern.

    Shark Bite fittings are crap, I will agree. They are really aimed at DIYers. If you really want to do away with sweat fittings find a plumber that will do Viega Pro Press crimp fittings. Yeah, they have a buna-N "O" ring, but they will never fail.
     
  13. Donut

    Donut

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    If you carefully read my original post (or my second post), you would understand why I want a source of plumbed hot water (as opposed to heating the water on a stove like regular restaurant kitchens). It is not uncommon for bakeries to use mixer/dosers, and I was curious to learn what other bakeries use as a source of plumbed hot water for their mixer/dosers.

    As for your "nonsense" comment, try searching for "cooking with hot water" and you'll find numerous warnings about it, including this 2017 article published by "Denver Water" which is Colorado's oldest and largest water utility, and which supplies water to the 1.4 million people in the city of Denver and many surrounding suburbs:


    That's right from the horse's mouth, not just from a bunch of internet basement fear-mongers.

    For the record, the shopping center where I will be leasing our space was built in 1984. The kitchen construction within our leased space will be new, but not the entire building. That said, I don't see this as a big concern either, especially since I will be putting in new piping from the hot water heater to the dough prep station.

    Furthermore, I've recently discovered that 3M makes a "whole house" cartridge filter that contains both a media filter for removing sediment and an activated charcoal block filter for removing chemicals; it has a 100,000 gallon filtering capacity and is rated to flow 20 gpm. I can install this at our water supply's point-of-entry and completely filter all the water, including the water entering our water heater.
     
  14. Donut

    Donut

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    Where did I state that I was trying or planning to warn the general public? I'm simply doing my best to provide the highest quality product to my customers.
     
  15. Vjan

    Vjan

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    Post #7. 2nd reply.
     
  16. halb

    halb

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    That can be true, particularly with water heaters that have been in service for awhile and are starting to corrode. But how is hot water from the tap any different than what you are trying to do? Aren't you heating water (albeit filtered) with a water heater and providing it to your mixer/doser? That water heater is going to corrode after awhile too unless there is some laboratory stainless steel heater out there that I never looked for.

    As to concerns about lead, it's rare today to find lead plumbing. In the event that it is found, it would have to be replaced. Lead service lines are another matter, and some backward municipalities still maintain not only lead service lines but lead distribution. If you are faced with that problem, it's not your fault but you have to look into installing filtration where it enters your premises.

    If any old copper plumbing was soldered with solder containing lead, given that lead containing solder has been banned since the 80's, nearly all of the lead would have been leached out by now. So I consider that a non issue.

    The simplest way to alleviate your concerns is to have water samples tested. Take samples from where it enters your premises, the point of use after the water heater and after the hot water has been sitting in the plumbing for several hours. This is much more scientific than going off on some tangent over what might be based on internet articles.
     
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  17. Seoul Food

    Seoul Food

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    I just can't imagine the amount of lead that may or may not be present in the water for making donuts would be enough, or that someone would continually eat enough of said donuts to warrant a serious health concern. There are plenty of foods that have contaminates in them but a lot of times it will take a considerable amount over a period of time to have any ill effects.

    Also, if you are planning on going this route: municipal water line --> new copper --> filter --> hot water tank --> new copper I don't see why you couldn't use the hot tap water as it has been taken from a cold state and filtered as you said it should, heated and transferred through new plumbing which will not have any lead, right?
     
  18. brianshaw

    brianshaw

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    One reason I’ve heard for not using hot tap water is because it can get to unsafe bacteria-breeding temps when standing in the pipes. Plus, there is generally a lot of crud that builds up in hot water heaters.
     
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  19. halb

    halb

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    That would be Legionnaires' disease. It's a respiratory infection that you can get it by breathing in a mist of the infected water, not by ingesting it. Common sources are the wind blowing water mists off air conditioning cooling towers and fountains that haven't been treated. But more alarming is that you can get it by taking a shower if the shower hasn't been used for a length of time, like a vacation house. So always let the water run to replace the water in the water heater and plumbing before you jump in the shower if it hasn't been used recently. It's also a good idea to keep the water temperature at least 140F- and I hear now that the new advisory is 160F to kill off any bacteria.
     
  20. Seoul Food

    Seoul Food

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    That may be true but when putting it into the context of the OP I don't think it is as relevant. If the OP is putting in all new plumbing/hot water tank added to the fact that he will be using the water on a pretty consist basis with either the water for donuts or the water for hand washing I don't really see a massive threat for contamination. Our water tank is already holding at above 160 degrees so if he had to turn the hot water down to get around 100 degrees where he wanted for donuts I do not seriously believe bacteria would grow in that small window of time to the point of making people sick.