What is memory foam made of?

Memory Foam is a chemically produced foam, not too dissimilar to other foams you may have around the house. The difference is that Memory Foam is viscoelastic, or reacts and softens when subjected to heat.

VASCO 60Memory foam comprises of a number of chemical compounds used in its manufacture. Each brand may use different suppliers from different countries. This means that Memory Foams wont all share the same exact chemical compositions, each manufacturer will have their own recipe or formula. Each country also has its own chemical standards and accepted rulings of the use of them. A cheaper mattress from China may have a completely different ‘accepted’ set of chemical ingredients to one manufactured in the UK or USA. This ingredient list is kept a close guarded secret.  The Fire Regulations set by each country differ so imported Memory Foams may not meet the requirements of the UK.

That said there is a set of some 61 ingredients that are likely to be found in Memory /Visco elastic Foam.

Memory Foam is manufactured as a polyurethane foam using water, isocyanates (common examples toluene diisocyanate and methylene diphenyl diisocyanate) and polyols (common examples glycerine, petroleum, plant based oil derivatives) which are usually sprayed onto each other on a conveyor belt and then combined with a reactant that acts as a catalyst to create an open cell structure.

This may all sound very complicated but we simplify it as follows:

  • Water and a number of chemicals are combined (isocyanates & polyols), with an agent (reactive)
  • This makes them then react a certain way aerating them (giving them the open cell structure) to create a foam.
  • These are either sprayed continuously onto a conveyor belt or then poured into moulds and allowed to dry.
  • Once dry you have the finished product of ‘Memory Foam’.

A small change in some of the chemicals then alters the density, hardness or response rate of the foam. The majority of foams are manufactured using a slabstock manufacture process, which is the process above of making large ‘slabs’ of Memory foam using the conveyor belt process rather than individual moulds which would be incredibly expensive.


The end result is a foam which reacts to heat, making it mould and conform to whatever shape and pressure that is placed upon it, usually a human! Memory foam is often described as a foam that allows you to sink slowly into it as it moulds to your body.  Interestingly people either love or hate this sensation, but fear not there are a variety of variations of these properties!  Hybrid Foams for example don’t need as much heat or mould as much. Latex on the other hand is vastly more responsive than memory Foam.


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  • Kerry says:

    Good morning,
    Just over 3 years ago we made a huge expensive decision to purchase adjustable Tempur beds and mattresses. Initially we found the sleeping experience wonderful but quite soon after the “wonder” wore off.
    I realised the mattress was making me feel hot and as I have entered into that “woman’s age” period of my life it has become increasingly worse.

    Height and weights? 1. 5ft 9 (hope you still work in old money!) 12 stone and 2. 5ft 8 11 stone

    I also suffer with muscle problems in my back and find the turning and getting off the mattress increasingly difficult and I’m only 55! I’ve actually strained my back just turning over in the night.
    Now every morning I wake with lower back ache and as it wears off during the day I can only assume it’s the mattress. I just get pain free and it’s almost time to go to bed again and so the circle continues. My husband does not have the pain problems I have but does not wake feeling rested. There are no signs of indentation on the mattresses so it would seem that Tempur are just not for us.

    I’ve spent a fortune on coolmax bedding, toppers and finally a duet bespoke made duvet which is 10.5 tog on my husbands side and 6 tog on mine (this has helped considerably)
    We love the adjustable capabilities of the frame so don’t really want to change that and as the mattresses are like 2 singles on a linked base we would have to have bespoke sizes.

    I wouldn’t expect you to recommend a particular mattress for us, as like buying a pair of shoes, it’s a very individual choice. But having looked at your website, you seem to have lots of impartial knowledge. Well done, it’s the best informative site I have ever come across.

    So, we are looking to change our mattresses, comfort and support are paramount together with finding something that will fit our current adjustable beds of medium firmness. I’ve been thinking of an organic natural latex to combat the heat problem but don’t know if I’d still have the turning getting out of bed problems and would appreciate your comments. Kerry.

    Thanks for getting in touch Kerry. You’re not the only one who has raised issue with tempur and memory foam getting too hot in the night, its one of the features of such foams that they retain heat. In fact its quite a common complaint for those that get too hot in the night. This is due to the fact memory foam is visco elastic and so requires heat to mould, this means in turn it is heat retentive. That is why you get the dip or hollow that you struggle to turn out of in the night because it has moulded. Typically memory or tempur style beds are slow to respond once you’ve moulded into them unlike Latex and Hybrid foams.

    I think that based on your issues a natural latex mattress would be more suitable. Latex is incredibly breathable and far more responsive than memory foam. That means it returns almost instantly to its original shape when you turn or move.

    Please have a look at our Fusion Range of natural latex mattresses. We craft them in either a medium or a firm tension Latex. They are fully turnable and can be used with adjustable beds. I think the medium would be ideal but I can advise on the best for you if you can provide me with your weights and heights.

    As for the coolmax bedding its very hard to use a sheet to completely reduce the heat, we find that changing the tog of your duvet is far more effective than spending a small fortune on heat removing covers! If you are that warm no amount of sheeting will remove it I’m afraid- Lee

  • Jodie C says:

    Hi, I’ve seen some really cheap memory foam mattresses on ebay by a company called Durest, can you tell me what you think of them? What’s worried me is there are a number of bad reviews about them online and I can’t find out any details about their beds! Thanks Jodie

    Hi Jodie, We had another comment on Durest the other day. I’ve not been able to find out much about them apart from they seem to be an ebay seller. I can’t find out anything about the components, details or specifications of their mattresses. We always advise you need this information to make an informed decision. So I’d get in touch directly with them to find out more.

    We always state that if you can’t find out anything about the mattress you would be wise to exercise caution. If a manufacturer is refusing to give this information what does this say about them? I may sound overly critical but this business model of hiding what’s in your beds or keeping it secret is a far cry from our business of transparency and honesty. Lee

  • Karen (Submitted by Email) says:

    Dear John,

    Many thanks for your informative website. It however has left me slightly at a loss as to what to do.

    I bought a Harrison MT 3000 impression medium mattress 4 years ago. It has been a wonderful mattress, solving low back problems. However, it is sinking where we lay. We feel like we are hammock cocoons now!

    Harrison have sent a rep to have a look. They have accepted the fillings have settled excessively.

    They have offered a replacement for a£780 charge.

    My thoughts on this are:-

    I have loved the memory foam comfort but don’t want to pay again, and in theory pay every 4 years, for this comfort.

    I don’t want to pay again if the mattress wasn’t up to scratch from the beginning, rather than it being bad luck.

    Is this to be expected with memory foam?

    I really do like your suggested honesty and would like to further investigate getting a product from you that will suit us. I am going to negotiate with Harrison regarding compensation rather than us having to pay for a replacement.

    I would very much appreciate your opinion, largely, am I expecting too much from the mattress and therefore how much should I fight Harrison for compensation or accept the replacement via the charge?

    Many thanks

    Hi Karen, The average lifespan of a bed is deemed to be 7 years which is what you should be expecting when buying a quality mattress. Obviously the cheaper you go the more you compromise the materials and quality if components. Memory foam in particular is a very tricky component because it has literally hundreds of variants varying in quality and lifespan. All memory foam is not the same. There are top notch foams and substandard import foams, some of which don;t even pass fire retardancy regulations!

    Memory foam over time will like over materials degrade and compress. Usually the most compression / softening happens in the first 6 months. If however you have been sold too light a density memory foam it may be that the foam was never intended for your body weight or tension preference. Its getting confusing I hear you say!

    I would expect after 4 years a memory foam bed to have some impressions on it and to be compressed but not to the point of a hammock effect you’re describing. Memory foam is fantastic at pressure reliving qualities but has been superseded by the likes of Hybrid foams and Latex in recent times which are more robust and have a longer lifespan.

    I can’t advise you directly on how to proceed with Harrisons but can give you some advice on what I would recommend for you if you were buying a new bed. I would need your height and weight firstly though so would advise you call in. If you like memory foam but are concerned about sagging or excessive dipping I’d ask you to have a look at the hybrid foam cool blue or even better, natural latex. If you can get in touch with some more specifics of tension, bodyweight etc I’ll happily tailor the advice further. Many thanks – Lee

  • Evelyn says:


    I am looking at your website and am impressed with the products and information on offer. Before I decide on my purchase, I have a few questions please.

    I am looking to purchase the below:
    1) Fusion Range: Fusion 4 100% Natural Latex Firm (Superking with base)

    2) Genesis Range: 2 x Memory Medium Firm (Single with base)

    My questions are:
    1) Does your bed comes with a headboard? (did not see headboard mentioned even though it’s shown on pics)

    2) I intend to use the 2 single beds as child’s bed /guest bed. I know that memory foam mattress would be suitable for my guests but I am not too sure with my child using the same. I’m worried that it might be too firm, would maybe adding a different topper helps? If not, what type of mattress in your range would be suitable for a child 3 year old up?

    3) How long does it take for my order to be ready for delivery?

    4) I will be moving to a mid-terrace house with half-landing staircase, would that pose a problem to delivery?

    5) How do we arrange for date and time of delivery? We have yet to move in to the new place, so ideally would like to be able to confirm nearer to the date (expected date at the moment is 5th Sept)

    Look forward to your reply.

    Many thanks,

    Hi Evelyn, Headboards are extra to the mattress and base price a super kingsize headboard is £250 and single headboards are £125 each.

    Please see our John Ryan Headboard designs here and you can view the fabric options available to have your divan bases and headboards covered in here.

    The Genesis mattress will be fine for small children to use as they will get all the support they need from the topper, and the heavier guests will then get the added support from the core mattress below.

    Orders are placed online via the website and we place the orders once a week every Wednesday with the manufacturers, from this date to delivery to yourself is usually within about 4 weeks.

    The products you are looking at all come vacuum packed and boxed so there will be no problem getting the products into your property.

    The couriers call you direct to arrange the delivery with you. Hope that helps – Gary

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