This roasted hazelnut ice cream has an extremely smooth and creamy texture with a sweet roasted hazelnut flavour. I highly recommend using a fine hazelnut paste. This recipe will be split into three sections: SECTION 1 will cover the science of ice cream making and preparation tips, SECTION 2 the ingredients and a detailed recipe, and SECTION 3 a quick recipe. I strongly recommend starting with section 1.
THIS RECIPE WAS UPDATED ON 13TH FEBRUARY 2016
SECTION 1: THE SCIENCE OF ICE CREAM MAKING AND PREPARATION TIPS
1. FREEZING THE BOWL AND EQUIPMENT
For this recipe, I use the Cuisinart ICE 30BC (click here for my review), which comes with a removable bowl that needs to be frozen overnight before it can be used. The following is a list of domestic ice cream machines with in-built compressors that I’ve tried and would recommend:
- Lello Musso Pola 5030 (click here for my review),
- Lello 4080 Musso Lussino (click here for my review)
- Cuisinart ICE-100 (click here for my review)
- Breville BCI600XL (click here for my review),
To view the top selling ice cream makers on amazon, please click here
TIP#1 – Cling film
For the Cuisinart ICE-30, the day before you start making your ice cream, take the bowl and cover the top with cling film; use an elastic band to help keep it in place. The cling film will help prevent water vapour in your freezer, as well as any ice that may fall in, from freezing to the inside of the bowl. Any water that freezes at the bowl wall will likely be incorporated into the mix during the churning process, with possible implications for texture if a sufficient amount is incorporated.
It’s also important to freeze enough water in some ice trays to make an ice bath. We’ll be using an ice bath to quickly cool the ice cream mix once it’s been heated, minimising the time the mix spends in the ‘danger zone’, between 5 (41) and 65°C (149°F), where bacteria likes to multiply.
TIP#2 – Freezing the container
Take a 1 litre plastic container and the freezer bowl and put them in your freezer overnight. Freezing the plastic container will remove any stored heat. Heat stored in the container causes the ice cream that contacts the side and bottom to melt, resulting in an increase in ice crystal size.
1.1. Ice crystals in ice cream
Ice crystal size is a critical factor in the development of smooth and creamy ice cream (Donhowe et al. 1991). Smooth and creamy ice cream requires the majority of ice crystals to be small, around 10 to 20 µm in size. If many crystals are larger than this, the ice cream will be perceived as being coarse or icy (Drewett & Hartel 2007; Goff & Hartel 2013).
Ice crystal size is determined by the mix composition and by the freezing process, of which there are two stages: 1. the dynamic freezing stage, where the ice cream mix is frozen in an ice cream machine while being agitated to incorporate air, and 2. the static freezing stage, where the partially frozen ice cream is hardened without agitation in a freezer. Ice crystals form only during the dynamic freezing stage and grow during the static freezing stage.
In this recipe, we will be looking at what we can do to promote the development of small ice crystals during the dynamic freezing stage and then preserve these small crystals during the static freezing stage.
2. Setting the freezer temperature
Your freezer’s temperature has a significant effect on residence time and on ice crystal growth.
2.1. Residence time
If you’re using the Cuisinart ICE 30BC, or any other machine that requires you to freeze the bowl before it can be used, your freezer’s temperature will have a considerable effect on residence time. Residence time is the length of time the ice cream mix spends in your ice cream machine during the dynamic freezing stage and has a significant effect on ice crystal size (Russell et al. 1999; Goff & Hartel 2013; Drewett & Hartel 2007; Cook and Hartel 2010). Russell et al. (1999) found that ice creams made with shorter residence times had smaller ice crystals.
Your freezer’s temperature determines the temperature of the freezer bowl when you leave it to freeze overnight. Lower freezer bowl temperatures can lower the bulk temperature of the ice cream faster, reducing residence time and improving the ice crystal size distribution (Russell et al. 1999; Drewett & Hartel 2007).
TIP#3 – Lower your freezer’s temperature
Set your freezer’s temperature as low as it will go, ideally between -23 to -29°C(-9.4 to -20.2°F), to get your freezer bowl as cold as possible. The colder you can get your freezer, the colder it will get the freezer bowl and the shorter the residence time is likely to be. The shorter the residence time, the smaller the ice crystals and the smoother the texture is likely to be.
I’ve found that my freezer’s temperature has a noticeable effect on residence time when I use my Cuisinart ICE 30BC. When I set my freezer to ‘super freeze’, which gets the temperature down to about -27°C (-16.6°F), it takes about 18 minutes to churn an 800g batch of ice cream. When I set it to -18°C (-0.4°F), it takes about 30 minutes to churn the same amount.
2.2. Ice crystal growth
No new ice crystals are formed during the static freezing stage but the existing small crystals grow in size until the temperature decreases to -18°C (-0.4°F), or ideally -25 to -30°C (-13 to -22°F), to halt this growth. If the ice crystals grow too large during the static freezing stage, a corse or icy texture will develop (Arbuckle 1986).
Quick hardening during the static freezing stage limits ice crystal growth (Goff & Hartel 2013). Similarly, Donhowe (1993) showed that faster cooling of ice cream during hardening resulted in smaller mean ice crystal size.
TIP#4 – Promote quick hardening
To promote quick hardening during the static freezing stage, make sure your freezer is as cold as it will go, ideally -25 to -30°C (-13 to -22°F). Place your ice cream at the back of your freezer where it’s coldest. Try and clear some space in your freezer when chilling your ice cream. Putting ice cream in a densely packed freezer will reduce heat transfer, resulting in an increase in freezing time.
3. Setting your fridge temperature
It’s also important that you set your fridge to between 0 and 2°C (32 and 35.6°F) to increase the rate of crystallisation of the fat globules when you age your mix overnight. Crystallisation of fat during the ageing process helps maintain the shape of ice cream when it is served and also helps minimise the rate at which the ice cream melts (Goff & Hartel 2013). If you don’t allow the fat globules sufficient time to crystallise, it is likely that your ice cream will suffer from relatively fast meltdown and less retention of shape.
4. The size of your pan
The size of the pan you use will affect the rate of evaporation and heating time. I use a large pan with a 23cm diameter to achieve a 15% reduction after 25 minutes heating at 72°C (162°F). If your pan is smaller than 23cm, you will likely need to continue heating your mix for a further 5 minutes or so to reach the desired 15% reduction. Let’s have a look at why it’s important that you heat your mix for the full 25 minutes at 72°C (162°F) and achieve at least a 15% reduction. .
5. The importance of heating time and temperature
There are three principal reasons why we will be heating our mix to 72°C (162°F) and holding it there for at least 25 minutes: 1. to pasteurise the mix, 2. to improve foaming and emulsification, and 3. to improve body and texture.
5.1. Pasteurisation
If you’re running a business and making ice cream to sell, you need to ensure that you are in compliance with food safety legislation. Here in the U.K, the Dairy Products (Hygiene) Regulations 1995, Schedule 6, part v 1 (a) states:
1. Pasteurised ice-cream shall be obtained by the mixture being heated—
to a temperature of not less than 65.6°C (150.1°F) and retained at that temperature for not less than 30 minutes;
to a temperature of not less than 71.1°C (160°F) and retained at that temperature for not less than 10 minutes; or
to a temperature of not less than 79.4°C (174.9°F) and retained at that temperature for not less than 15 seconds.
Ice cream needs to be pasteurised in order to destroy all pathogens and the enzyme phosphatase that may be harmful to health. This is just as important for those of us making ice cream to sell as it is for the home cook.
5.2. To improve foaming and emulsification
The second reason we’ll be heating our mix to 72°C and holding it there for 25 minutes is to improve whey protein foaming and emulsification. Foam formation and its stability is important for texture and for the retention of air that is incorporated into the ice cream during the dynamic freezing stage. Heating milk so that the whey proteins undergo partial protein unfolding yields a more voluminous and more stable foam and improves the emulsifying characteristics of milk protein (Philips et al., 1990). At high temperatures, however, foaming and emulsifying characteristics may be impaired due to protein aggregation (Phillips et al., 1990).
At what temperatures, then, do the whey proteins found in milk start to undergo beneficial partial protein unfolding and at what temperatures do they start to aggregate? Sava et al. (2005) held that thermal denaturation of whey protein involves 2 steps: an unfolding step at 70 to 75°C (158 to 167°F), and an aggregation step at 78 to 82.5°C (172.4 to 180.5°F), that mostly follows unfolding.
TIP#5 – 72°C (162°F) for 25 minutes
I’ve found that when I hold my mix at temperatures above 72°C (162°F) for a prolonged period of time, the unpleasant ‘eggy’ hydrogen sulphide taste begins to form and becomes noticeable on eating. I would therefore recommend heating your ice cream mix to 72°C (162°F) and holding it at this temperature for 25 minutes as this significantly improves ice cream body and texture. I’ve run several tests where I have kept the temperature constant at 72°C (162°F), as well as the composition, but have varied the heating times. I’ve found that a mix heated for 25 minutes produces smoother and creamier ice cream than compared to mix heated for 5, 10, and 15 minutes at the same temperature.
5.2.1. Surface hydrophobicity
Surface hydrophobicity is also important in determining emulsifying activity (Monahan et al., 1993). Damodaran (1996) held that denatured proteins have better foaming properties, attributed to increased hydrophobicity, and greater interfacial contact. Sava et al (2005) found that surface hydrophobicity increased considerably at temperatures between 70 and 77.5°C (171.5°F) when whey protein was heated for 45 minutes, with greater increases noted after longer heating times.
Functionality of whey protein also depends on its solubility. Heating at a temperature between 70 (158) and 75°C (167°F) results in a minimal loss of solubility. Sava et al. (2005) noted a decrease in solubility of only 10 to 20% compared with the native protein after 45 minutes.
The literature points to an optimal heating temperature for whey protein at somewhere between 70 (158) and 75°C (167°F). In this temperature range, whey proteins undergo reversible unfolding, which improves foaming and emulsification. Holding whey protein at between 70 (158) and 75°C (167°F) for an extended period of time significantly increases surface hydrophobicity with only a minimal loss of solubility, which improves foaming.
5.3. To improve body and texture
The third reason we are going to heat our ice cream mix to 72°C (162°F) and hold it there for 25 minutes is that heating milk also improves body and texture because of the denaturation of proteins and the consequent increase in their water-holding capacity (Goff & Hartel 2013), which contributes to smooth and creamy texture by helping to minimise ice crystal growth.
6. Weigh your pan
Before you start preparing your mix, it’s important to first weigh your pan and record its weight. This is necessary so that you can check the level of reduction after 25 minutes heating.
The starting weight of our mix will be 1000g. After 25 minutes of heating and a 15% reduction, you should have a mix weight of 850g plus the weight of your pan. If your mix weighs more than 850g plus the weight of your pan, put it back on the heat and continue heating.
Here is how to check the level of reduction after heating for 25 minutes:
My 23cm diameter pan weighs 1606g.
1606g pan + 1000g starting mix = 2606g starting weight.
After 25 minutes of heating, my total weight (1606g pan + 850g 15% reduced mix) should be 2456g.
If my total weight after 25 minutes heating is greater than 2456g, I will continue heating until the weight falls to 2456g or less.
7. Why is skimmed milk powder added to ice cream?
The use of skimmed milk powder in commercial ice cream making is usually associated with economy-style ice cream as it is a cost effective way of reducing the more expensive cream whilst maintaining total solids. In homemade ice cream, however, I’ve found that it is essential for the promotion of smooth and creamy texture.
Skimmed milk powder’s primary role in homemade ice cream is to increase the non-fat milk solids (NMS), namely the whey protein. Flores & Goff (1999) demonstrated that milk proteins had a large impact on texture by limiting ice crystal size and enhancing their stability. I’ve not been able to achieve the same smooth and creamy texture in my homemade ice cream after 25 minutes of heating without the addition of skimmed milk powder.
SECTION 2: INGREDIENTS AND DETAILED RECIPE
Makes just under 1 quart (1 litre) of ice cream
PREP TIME:
About 15 minutes
HEATING TIME:
About 30 minutes for the mix
EQUIPMENT:
Food thermometer
Ice cream maker
A zip-lock bag
Ice trays
1 litre plastic container
Ingredients:
Cream
Full-fat, semi-skimmed, or skimmed Milk
Unrefined sugar
Skimmed milk powder
Egg yolks
110g fine roasted hazelnut paste
1. The importance of butterfat
Milkfat contributes significantly to the rich, full, and creamy flavour and to the smooth texture of ice cream (Goff & Hartel 2013). It’s important that you check the fat content of the cream and the milk that you’ll be using in order to calculate your mix.
Above is the spreadsheet I use to calculate my mixes and I’ve included it for you guys to calculate the exact quantities of milk and cream that you will need. Simply enter the cream fat (usually found on the back of the cream carton and around 35% for you guys in the U.S) and milk fat percentages in the two yellow cells at the top of the spreadsheet. This will then give you the quantities of milk, cream, sugar, egg yolks, and skimmed milk powder needed (in grams) in the cells in blue.
You can use full-fat, semi-skimmed, or skimmed milk. Here in the U.K, our double cream and skimmed milk contain around 47.5% and less than 0.5% of fat respectively, which I have entered as the default values. I recommend using organic milk and cream and organic free-range eggs whenever possible. I use organic milk and cream and organic free range eggs for my business and find that I get a much richer flavour from organic milk and cream and a much deeper colour from free range egg yolks.
2. Preparing an ice bath
Before you start preparing your mix, take a large bowl and fill it with enough ice to make an ice bath. Have a large zip-lock freezer bag ready next to the bowl, along with some table salt. We will be using the zip lock bag and water bath to ensure that the mix is cooled as quickly as possible once it has been heated, minimising the time the mix spends in the ‘danger zone’, between 5 (41) and 65°C (149°F), where bacteria likes to multiply. The longer your mix spends in this ‘danger zone’, the more bacteria is likely to multiply, imparting an undesirable taste and smell.
3. Heating the mix
Weigh your pan and record its weight. We will use this weight to check whether we have achieved the desired 15% reduction after 25 minutes of heating.
Once you’ve prepared the ice bath and weighed your pan, add the sugar and skimmed milk powder followed by the egg yolks. Mix the yolks, sugar and skimmed milk powder to help prevent the yolks from curdling during heating.
Add the cream and milk and spend a good minute or so mixing all the ingredients before you switch on the heat.
Over a medium heat, heat the mixture until the temperature reaches 71°C (160°F), making sure that you are constantly stirring. You’ll risk burning the proteins and curdling the egg yolks if you do not constantly stir the mix.
Once the temperature reaches 71°C (160°F), turn the heat down to medium-low, move your pan slightly off the heat, and continue heating and stirring until the temperature reaches 72°C (162°F). Use your thermometer to keep your mix at 72°C for 25 minutes, adjusting the position of your pan to help regulate the temperature.
4. Cooling the mix
After 25 minutes, take the pan off the heat and weigh it. If the weight is greater than 850g plus the weight of your pan, place it back on the heat and continue heating for another 2-3 minutes or until you get the weight down sufficiently.
Carefully pour the mix into the zip-lock bag and seal. Place the bag in the water bath and pour about a tablespoon of salt onto the ice to lower the temperature and cool the mix faster.
Once the mix has cooled to room temperature, place the zip-lock bag in the fridge and leave overnight to age.
5. Churning the mix
Once you’ve allowed your mix to age overnight, carefully pour it into your ice cream machine followed by the roasted hazelnut paste.
TIP#6 – Leave the compressor running for about 15 minutes
If you’re using an ice cream machine with an in-built compressor, with the bowl in the machine, switch on the compressor and leave it running for 10-15 minutes before adding the mix. This will ensure that the freezer bowl is as cold as possible when the mix is added, which will contribute to a reduction in residence time.
TIP#7 – Use your thumb to push the dasher against the side of the bowl
If you’re using the Cuisinart ICE 30BC, use your thumb to push the dasher against the side of the bowl as soon as you pour in the mix. This will ensure that the dasher scrapes off the layer of ice that freezes to the side of the bowl. Any ice that is frozen to the side of the bowl will act as an insulator, slowing the release of heat from the ice cream to the bowl and increasing the residence time. Remember that the longer the residence time, the larger the ice crystals will grow and the sandier the texture is likely to be. Goff & Hartel (2013) note that even a very thin layer of ice remaining on the bowl wall can cause a dramatic reduction in heat transfer. The longer you keep the dasher pushed against the bowl wall, the shorter the residence time is likely to be.
Use a spoon to push along any static lumps of ice cream and ensure that the mix is constantly moving whilst in the machine. Static lumps will likely take longer to freeze, giving the ice crystals more time to grow.
6. Extraction time
Your mix will be ready when it develops a nice dry, stiff texture, and starts forming ribbon-like swirls. When you remove the dasher, your ice cream should stick firmly to it.
The point at which your mix is ready for extraction will vary from 14-45 minutes depending on the machine you use. For the Cuisinart ICE 30BC, your ice cream should be ready at around 30 minutes of churning. For the Cuisinart ICE-100 and the Breville BCI600XL Smart Scoop, this should be after 32 and 33 minutes respectively. For the Lello Musso Pola 5030, your ice cream will be ready after around 14 minutes and the Lello Musso Lussino 4080 after about 16 minutes.
Just before your mix is ready, quickly take the plastic container out of the freezer and have a large and a small spoon ready. It’s important that you empty your ice cream from the freezer bowl and get it into your freezer as quickly as possible. The extraction time, that is the time it takes to remove the ice cream from the machine and get into into your freezer, has a considerable effect on ice crystal size. This is because as you extract your ice cream from the bowl and into a plastic container, it spends time at room temperature. At this relatively warm room temperature, some of the ice melts from the large ice crystals and the crystals that were initially small melt completely. When you then get your ice cream into your freezer for the static freezing stage, the melted ice re-freezes onto the large ice crystals that survived. The result is that the total number of ice crystals is reduced and their size increases, the perfect formula for coarse texture.
TIP#8 – Get your ice cream into your freezer as quickly as possible
Just holding ice cream at relatively warm room temperatures as you’re extracting it from your machine results in an increase in mean ice crystal size and a decrease in the number of ice crystals present (Goff & Hartel 2013). It’s therefore important that you extract the ice cream from the freezer bowl and get it into your freezer as quickly as possible.
7. Static freezing
When you finish churning your ice cream, it will be extracted from your machine at around -5°C (23°F) and will have a consistency very similar to that of soft serve ice cream. Ice cream is usually served in its scoopbable state at around -12°C (10.4°F) and so you will need to get your ice cream into your freezer to harden. Because ice crystals continue to grow until the temperature drops to -18°C (0.4°F), ideally -25 to -30°C (-13 to -22°C), the faster you get your ice cream below these temperatures, the less ice crystal growth will occur.
After about 4 hours, depending on your freezer, the ice cream will have a nice firm scoopable consistency, somewhere around -15°C (5°F), and be ready to serve.
TIP#4 (again) – Promote quick hardening
To promote quick hardening, make sure your freezer is as cold as possible when you freeze your ice cream. Place your ice cream at the back of your freezer where it is coldest. Try and clear some space in your freezer when chilling your ice cream. Putting ice cream in a densely packed freezer will reduce heat transfer, resulting in an increase in freezing time.
8. Serving your ice cream
Serve your ice cream at around -15°C (5°F). If you can wait, allow the ice cream to warm to below -12°C (10.4°F) before eating. As the serving temperature is increased from -14.4 (6.1) to -7.8°C (18°F), flavour and sweetness become more pronounced.
9. Storing your ice cream
At -18°C (-0.4°F), it is recommended that homemade ice cream be kept for about a week. Ice cream can be stored for several weeks at -25°C (-13°F), and several months at -30°C (-22°F) (Goff 2012). Even at these low temperatures, however, ice crystals will eventually start growing in size. The longer you store your ice cream in the freezer, the larger the ice crystals will grow and the sandier the texture is likely to be.
Try to minimise the number of times you take your ice cream out of the freezer as temperature fluctuations especially promote recrystallisation during the storage of the ice cream (Donhowe & Hartel 1996). Goff & Hartel (2013) state that temperature fluctuations may be associated with 1. changes of temperature of storage, 2. heat shocks, where ice cream is left at room temperatures for extended periods of time, and 3. opening and closing of doors in freezers and storage cabinets. Changes of temperature of storage are associated with frost-free home freezers where temperatures can vary quite widely during the frost-free cycle (Ben-Yoseph & Hartel 1998). Heat shocks occur when ice cream is removed from the freezer, thawed before serving, and then the unfinished ice cream returned to the freezer.
TIP#9 – Switch off your frost-free setting
If possible, switch off your frost free setting when storing ice cream to prevent temperature fluctuations, which contribute to ice crystal growth.
SECTION 3: QUICK RECIPE
- Fill a large bowl with some ice. Place some table salt and a zip-lock bag next to the bowl ready for later.
- Combine the sugar, skimmed milk powder, egg yolks, cream, and milk in a large pan. Heat over a medium heat until the temperature reaches 71°C (160°F), making sure you are constantly stirring.
- When the mix reaches 71°C (160°F), quickly turn the heat down to low and position your pan slightly off the heat. Continue heating and stirring until the temperature reaches 72°C (162°F).
- Once the mix reaches 72°C (162°F), continue heating for 25 minutes, making sure you are constantly stirring.
- After 25 minutes of heating, carefully pour the mix into the zip lock bag and seal. Place the zip-lock bag in the bowl and pour about a tablespoon of salt over the ice.
- Once the mix has cooled to room temperature, place in the fridge to age overnight.
- The next day, pour the mix into your ice cream machine followed by the roasted hazelnut paste.
- After about 30 minutes of churning, depending on your machine, quickly empty the ice cream into a plastic container and place in the freezer for about 4 hours to harden.
- After about 4 hours, your ice cream will have a nice firm consistency and will be ready to serve.
I’d love to hear from you if you do give the recipe a try so do get in touch and say hello! All the best, Ruben 🙂
References
Arbuckle, W.S., 1986. Ice Cream (4th ed). New York: Van Nostrand Reinhold.
Ben-Yoseph E., and Hartel, R. W., 1998. Computer simulation of ice recrystallization in ice cream during storage. Journal of Food Engineering 38(3):309–29.
Cook, K. L. K., & Hartel, R. W., 2010. Mechanisms of Ice Crystallisation in Ice Cream Production. Comprehensive Reviews in Food Science and Food Safety. 9 (2).
Damodaran, S., 1996. Functional properties. In: Nakai, S., Modler, H.W. (Eds.), Food Proteins – Properties and Characterization. VCH Publisher, New York, pp. 167–234.
Donhowe, D. P., Hartel R. W., and Bradley R.L., 1991. Determination of ice crystal size distributions in frozen desserts. Journal of Dairy Science. 74.
Donhowe, D. P., 1993. Ice Recrystallization in Ice Cream and Ice Milk. PhD thesis, University of Wisconsm-Madison.
Donhowe, D. P., and Hartel, R. W., 1996. Recrystallization of ice in ice cream during controlled accelerated storage. International Dairy Journal. 6.
Drewett, E. M. & Hartel, R. W., 2007. Ice Crystallization in a Scraped Surface Freezer. Journal of Food Engineering. 78(3). 1060-1066
Flores, A. A., & Goff, H. D., 1999. Ice Crystal Size distribution in Dynamically Frozen Model Solutions and Ice Cream as Affected by Stabilzers. Journal of Dairy Science. Volume 82. 7. 1399–1407
Goff, H. D., 2012. Finding Science in Ice Cream. Presentation – Royal Canadian Institute for the Advancement of Science.
Goff, H. D. and Hartel R. W., 2013. Ice Cream. Seventh Edition. New York Springer.
Monahan, F. J., McClements, D. J. & Kinsella, J. E., 1993. Polymerization of whey proteins in whey protein-stabilized emulsions. Journal of Agricultural and Food Chemistry. 41.1826–1829.
Phillips, L. G., Schulman, W. and Kinsella, J. E., 1990. pH and heat treatment effects on foaming of whey protein isolate. Journal of Food Science. 55:1116–1119.
Russell, A. B., Cheney, P. E., & Wantling, S. D., 1999. Influence of freezing conditions on ice crystallisation in ice cream. Journal of Food Engineering. 29.
Sava, N., Rotaru, G. & Hendrickx, M., 2005. Heat-induced changes in solubility and surface hydrophobicity of β-Lactoglobulin. Agroalimentary Processes and Technologies. Volume 11. 1. 41-48.
Excellent recipe! As some other posters noted, I’ve had success with a version using (store bought) Nutella instead of hazelnut paste, replacing 40g of the sugar (I use dextrose) with 40g of dried brewers malt extract. Adding the Nutella to my Lello Musso at a temperature of 35F allowed some of the Nutella to remain unincorporated, with a swirl effect in the finished ice cream. One of the best ice cream recipes I’ve made. The maltiness is a nice complement to the hazelnuts and chocolate, though it’s still a hair sweet for my tastes…might further reduce the sugar next time to compensate for the sweetness of the Nutella. Great blog, keep those recipes coming!
Oh, and regarding the ziplock bags, chilling the mix in a Falk copper pan in the ice bath isn’t quite as quick as the bag method, but it does produce less waste. But if you do go with bags, I also think it’s worth using a new one for each batch, just to make sure your mix doesn’t leak, but instead of throwing them away afterwards you can simply wash them with soapy water and reuse them for something else.
Hey Ruben,
Just wanted to check in and say that I made this recipe but had to use full fat powdered milk (couldn’t find skimmed). Probably the best ice cream I’ve ever had…
Also made my own hazelnut paste which I couldn’t get absolutely 100% smooth but it ended up being great anyway. The ever so slightly rough texture of the nut paste made it seem more ‘authentic’ so to speak (you know there’s real hazelnuts in there). Also topped with a few roasted hazelnuts left over gave a strong hit of flavor here and there. Will be trying some candied hazelnuts for a topping next time.
Thanks for your amazing recipe!!
Hi,
I have just tried the recipe. Everything went perfect, but it is too sweet for me (I used a pure hazelnut paste, i.e. with no sugar added). Have you experimented with the sugar content? Will it affect the texture? I was thinking of perhaps adding 100 g instead of 140 g.
Matevz
Dear Ruben. This has been excellent reading. I have so many questions and can’t wait to try the recipe.
My main 2 questions are
1) is there a good protein / fat / egg ratio that most ice creams work off?
2) I’m really interested in learning more. Where would be a good place to gain some more knowledge. I don’t make ice cream professionally but I would love to learn how. What courses are the best?
Thanks in advance
In an ideal world what should be the contents of a “fine hazelnut paste”. Most seem to be 50% hazelnut 50% sugar.
Hi there Jacob!
Thanks for getting in touch and apologies for the delay in getting back to you. Always 100% fine, or refined, hazelnut paste if you can find it. TGT roasted hazelnut paste from southern Italy is excellent, although a little expensive. Pastes diluted with sugar won’t have the same intensity and you will also need to reduce the sugar content in your mix.
Hope that helps. Let me know if you have any other questions.
All the best,
Ruben
From ‘Hazelbrae’ at Hagley in Tasmania you can buy hazelnut butter – 99% toasted hazelnuts. I made ice cream using this product and it is superb.
Hi Reuben,
Thanks for the brilliant explanation on the science behind the heating of the milk. My question is –
What would be heating time for a smaller batch size e.g. 500 ml or a larger batch size of say 2 litres.
Thanks,
Prav.
Hi there Prav,
Thanks for getting in touch. The heating time for a smaller or larger batches would be the same, but you would end up with less mix for smaller batches because more water would evaporate, and more mix for larger batches. You would need to run a test batch to see how much water evaporates in your smaller batch, and then use the spreadsheet I’ve posted on the blog to adjust the mix amount after heating. You would also need to slightly reduce the quantity of each of the ingredients you use. You would need to do the same for larger batches. Because you can control the amount of not fat milk solids by adjusting the amount of skimmed milk powder in your mix, the point of heating for 25-30 minutes is to promote reversible protein denaturation, which is beneficial for texture, and increase surface hydrophobicity of the proteins, which improves emulsification and foaming.
Hope that helps. Let me know if you have any other questions.
All the best,
Ruben
Hi Ruben, great site!
I just have a couple of questions about pasteurisation for commercial ice cream making.
1) If my base doesn’t contains eggs, is pasteurisation still necessary?
2) Wouldn’t the addition of flavourings such as hazelnut paste, or other ingredients that you steep in the base to extract flavour, also have the potential to introduce bacteria? Therefore, why wouldn’t the mix need to be pasteurised with these other ingredients included?
Thanks a lot for your help
Cheers,
Nick
Hi there Nick,
Thanks for getting in touch and apologies for the delay in getting back to you.
That’s a very good question. My opinion is that if the mix doesn’t contain eggs and the milk and cream have already been pasteurised, then you don’t need to pasteurise the mix. It’s a very good idea to check with your local food safety inspector though, especially if you’re planning on making ice cream to sell, as I think that some health departments may still require you to pasteurise your mix even if you don’t use eggs.
Your second question is also a very good one. Yes the addition of flavourings such as nuts, vanilla beans, etc. do have the potential to introduce bacteria. It is up to you to determine whether the ingredients you add are of good quality and low enough in bacteria. I add my vanilla beans to my mix 2 minutes before the end of heating to make sure they are pasteurised but don’t heat the nut pastes I add because they’ve been roasted and handled properly by my supplier.
I’d highly recommend doing some reading on The Hazard Analysis Critical Control Point (HACCP) system, especially if you’re planning on making ice cream to sell.
Hope that helps. Let me know if you have any other questions.
All the best,
Ruben
Thanks Ruben, appreciate the help.
🙂
Also, please could you explain why don’t you mix the base with the hazelnut paste about 10-15 minutes before the 60′ heating period ends and then leave it overnight in the fridge so as the base mix mature with hazelnut paste?
Hi again Kostas!
I haven’t yet tried mixing the paste with the hot mix and leaving it overnight. Give it a go and compare it to a second batch mixed together in the ice cream maker.
All the best,
Ruben
Hi Ruben, I have tried my homemade hazelnut paste, which indeed was not so smooth, but this is why I put in the mix while heating it The heating dissolved it completely and the taste was very very good.
Hi Mr.Ruben,
what about making our own hazelnut paste for this recipe? Could we use a paste that is being made in food processor using hazelnuts and sugar? Can these two ingredients be used in this recipe?
Thanks.
Hi there Kostas!
Thanks for getting in touch! You can indeed make your own hazelnut paste if you can get it nice and smooth. I don’t think hazelnut paste made in a food processor will be smooth enough but give it a go and see how the ice cream turns out. A wet grinder might do the trick, but they are a little expensive. Try leaving the sugar out of the hazelnut paste as it might make it too sweet.
Hope that helps. Let me know if you have any other questions.
All the best,
Ruben
Why does your chart don’t consider the amount of fat in your hazelnut paste?
By the way neither you have considered the amount of fat in your egg yolk.
Hi Lee!
The percentage of fat in my charts is for milkfat only as this is what contributes significantly to texture. I do not include the fat from the egg yolks or from the hazelnut paste.
Hope that helps.
Ruben
Just a delightful blog. The best instructions on using the ICE-30. I didn’t think this machine is viable after reading dozens of reviews on Amazon. I will it a try … Any suggestion on icecream without milk protein and lactose? for the paleo ketogenic diet (Ghee, almond milk, coconut milk, cocoa butter are good) Thanks so much.
Hi Thom!
Many thanks for getting in touch! I’m sorry to say that I haven’t tried a recipe without milk protein and lactose. I think you can use coconut milk or almond milk as a substitute for milk but I don’t know how the texture will turn out. Protein plays an important role in promoting creamy texture so you may find texture an issue if you omit protein.
Let me know how you get on.
All the best, Ruben
I love this recipe and I’m trying to combine it with my Nutella and Chocolate recipe, but I do so wish you’d make the ingredient amounts more user friendly! How many egg yolks in 72g???? I couldn’t find this info online. Thanks Ruben!
Hi Valerie! Thanks for getting in touch. I thought giving ingredients in grams was the most user friendly way! My bad. The egg yolk of one large egg weighs about 17g so you’d need about 4 large egg yolks for 72g.
I would strongly recommend weighing your ingredients though as a slight increase in egg yolks may give a more pronounced eggy flavour. Similarly, if you use less than 72g of egg yolk, you may effect the total solids content of your mix which may in turn have a negative impact on texture.
To sum up, I would say stick to weighing your yolks!
Hope that helps. Let me know if you need help with anything else.
All the best,
Ruben
Hi Ruben,
First off – amazing site and knowledge, I do hope you can publish a book.
I plan on making this tomorrow so would like some clarification please.
– Does the hazelnut paste go into the mix straight off the bat and not like the vanilla
in the vanilla bean recipe where it is included post-heating?
– In relation to the ingredients – I’m having trouble gauging how much milk and cream is needed. I am using Sainsbury’s organic double cream which is 50% fat (I believe) so how much semi-skimmed milk and cream do I need to use in ml?
– The container I have to put the finished ice cream is a 2l container – will this affect the ice cream negatively (Bigger ice crystals)?
– If I were to adapt this to a chocolate and hazelnut ice cream (Nutella) what modifications would I need to make?
– I tried putting my thumb on the dasher during the ice cream churning process but felt like I was making a mess of things. Any further tips on how to improve that part of the process?
– If I were to add whole hazelnuts would you recommend chopping/grinding them down or leave whole? Should I add it to the machine in the last 5 minutes of churning?
Thank you for your time and energy!
Keep it up brother 🙂
Ravi
Hi Ravi!
Thanks for getting in touch. Here goes:
I add the hazelnut paste once I have added the mix to the machine. I think that if you were to infuse the paste, like you do the vanilla bean, the fat and yolk in the mix would dilute the hazelnut flavour slightly. Having said that, I have never actually made hazelnut ice cream by infusing the paste with the mix beforehand and so can’t say for sure whether what I’m saying isn’t a load of rubbish.
If you are using 50% fat cream, use 338g cream and 550g semi-skimmed milk at 1.7% fat; not sure what these would be in ml.
Using a 2 litre container won’t make a difference to the finished ice cream.
Chocolate and hazelnut ice cream sounds good! I’ve never tried this myself so can’t give you any exact quantities. You could always try substituting the hazelnut paste for pure nutella and see how that turns out.
With regard to the thumb on the dasher principle, I really don’t think it will have a major negative effect on the ice cream. I’m obsessive about my ice cream and so do every little thing possible to ensure it’s perfect but you will still get good results if you don’t follow the thumb on the dasher principle. You could also stick your thumb in the machine every couple of minutes or so to make sure that too much of the mix doesn’t get frozen to the side of the bowl.
Chopping whole hazelnuts into smaller pieces would add a nice contrast to the texture. I wouldn’t use whole hazelnuts because I think they would be a bit too tricky to eat and the flavour would be a bit overpowering with a whole hazelnut in your mouth. If you do add chopped hazelnuts, do try to add them towards the end of the churning process.
Hope that helps! Let me know how you get along with the recipe 🙂
All the best, Ruben
Hi Ruben,
Thanks for your reply – I very much appreciate your input as it has cleared any doubts I have had. I am in the process of making the mix as we speak.
Keep up the good work.
Thanks for your time
Ravi
Hello Ruben,
Currently I use a stainless steel container to cool down my mixture. A ziplock of course can be submerged and problably cools much faster.
Yet, do you buy a new one for each batch or do you clean them out?
Both options seem expensive/cumbersome/nature unfriendly 😉 . Did you try using some container?
Thanks,
Geert
Hi again Geert! I do indeed use a new ziplock bag for each batch. The cost does add up but I find it an effective way to cool the mix as quickly as possible. You could try pre-chilling a glass jar and then using that in an ice bath instead of a zip lock bag. I’m sure a jar would do the job just as well as a bag. I just find the bags easier to work with.
Hope that helps, Ruben 🙂
Dear Ruben, please send me an email, levinathan at gmail. I have an “ice cream science” challenge for you to solve. Well, it is more of an “ice cream reverse engineering” challenge, but I suspect you will be interested regardless.
Love your site with the detailed instructions for recipe. Best ice cream blog i’ve seen thus far. 🙂
Quick clarification: under “4. Size of pan section”, a 23cm diameter pan was 1st recommended but later after pic, a 30cm pan was specified for 60mins reduction time at 71.4 degrees. Just wondering which is correct?
My mix after heating seemed to coagulate upon cooling in the ice bowl. Final ice cream came out super sweet as well. Trying to see what exactly went wrong for me before trying your recipe again. I shall not give up!
I am from singapore and am considering to quit my job to start an artisnal ice cream shop too!!
Hi Gerard! Thanks for getting in touch! Oops – the sentence under the photo should have read ‘a 23cm diameter’ and not 30cm. You are likely to get a slightly creamier texture if you do use a 30cm diameter pan because of the slight increase in the amount of water that will be evaporated.
Sounds to me like there is too much fat if your mix is coagulating after it has been cooled. Were there large clumps in the mix after it was cooled or slight patches stuck to the side of the bag? Are you using cream with the same fat percentage as stated in the recipe? It is crucial that you use cream with the same percentage of fat as that stated in the recipe as too much will lead to large clumps of fat and too little will likely result in a sandy texture.
Hmm, the ice cream also shouldn’t normally be super sweet. Did you try the roasted hazelnut recipe? If so, does your hazelnut paste contain added sugar?
Great to hear that you are considering starting your own ice cream shop! I think gourmet ice cream in Singapore, especially during the summer, wouldn’t be a bad idea at all.
Let me know how you get on. All the best, Ruben
I made hazelnut-chocolate (Nutella) ice cream this week! I wonder how my ingredient breakdown would compare to your precise scientific approach!
Hi there!
Would be great to see some pictures of your delicious-sounding Nutella ice cream. Very cool that you make your own Nutella!:)
I posted the recipe and photos on my blog http://www.52scoops.com. The homemade Nutella is ultra thick – not at all like the store bought stuff. If you add more oil, it’d be thinner and more spreadable. But I figured since I was combining it with custard, it’d be fine (it was!) Ultra smooth and rich 🙂
Just found the ‘Read the rest of this entry’ button. Looks very very nice! 🙂
Your blog is absolutely fascinating – you need to write a book!
Hi Little Loaf! Many thanks for your kind words 🙂 I’d love to write a book on ice cream making at home. If you can recommend any good publishers, please let me know!
Hope the blog helps 🙂
I agree!