Hxxxxx, please accept this long and complicated email as a kind of Christmas gift. I almost sent you some homemade tablet, but I thought the recipe and the science behind it was a better gift. I'll finish with the recipe, but between now and then will be enough science and sugar-craft theory to be able to follow it. The reason I'm so knowledgeable on this is that I've spent about 18 months (not full time) trying to perfect vegan tablet for your sister - I have failed.
"Give a woman a pound of tablet and she'll eat it for a day. Give her the
recipe and she'll never bother to make it until she needs to demonstrate her
Scottish heritage."
Good tablet, as I'm sure you know should break like chalk but melt in the
mouth. In fact it dissolves in the mouth very readily, but close enough. Tablet
is a mixture of sucrose, glucose, fructose and water (also milk fats, solids,
lactose, lactic acid etc.) Close to its boiling point it is a smooth viscous
liquid and all the sucrose is dissolved. As it cools towards room temperature
there is a point at which the liquid is supersaturated with sucrose and it will
precipitate out as crystals. If the cooling is gradual and the mixture is
agitated the crystals will be very small and will give it the correct chalky or
sandy mouthfeel. If it weren't for the milk and the crystal size it's basically
the same stuff that they put on top of a Belgian bun.
All of sugarcraft is based on sucrose. In its anhydrous form it's a hard white
crystal, but it is highly soluble in water. A molecule of sucrose is actually a
molecule of fructose holding hands with a molecule of glucose at an Oxygen
atom. With water and heat we can perform hydrolysis to split the two simple
sugars apart and give them each an O-H pair to hold hands with. Golden syrup is
a sucrose solution that has been partly hydrolysed so that it contains all
three sugars. Golden syrup is called "semi invert" because a fully
hydrolysed solution would invert the direction that the solution would refract
light. Golden syrup has only gone partway.
When you're buying sucrose for sugarcraft it's called "sugar", maybe
table sugar, granulated sugar, white sugar, etc. It doesn't matter if it's from
cane, beets, or whatever, fairtrade, cruelty free, organic, as long as it's
white - it's all sucrose. All the brown sugars have some amount of molasses
either added to them, or not refined out. They aren't what you're looking for.
The amount of sucrose that you can dissolve in water is HIGHLY temperature
dependent. It's quite easy to make a sugar solution, boil off a little bit of
water, cool it slightly, find that the solution is now supersaturated and all
the sucrose precipitates out in big ugly crystals. Moreover to get to
hydrolysis we have to tiptoe through this supersaturated regime. If we were
making caramel or boiled sweets we would either add citric acid to act as a
buffer, or start with some extra fructose or glucose in the solution. Fructose
and glucose are both HIGHLY soluble in water so once hydrolysis has started the
danger of precipitation has passed. If we were making caramel the
crystallisation can occur and ruin a batch with just a tiny change in
temperature, the presence of any seed crystal, or just looking at it a bit
funny. In tablet this isn't ever really a problem.
As we continue to boil our solution water is driven off as steam and water is
combined with the sugars through hydrolysis. The amount of water decreases and
the proportion of the simple sugars increases. We can measure this
proportion in an oddly simple way - just measure the boiling point. It turns
out that the boiling point of the mixture is directly controlled by the
proportions of the various components. If you turn the heat under the solution
down until it's JUST boiling you can measure the boiling point with a sugar
thermometer. Various temperatures have names for example 235F is called
"Soft Ball Stage" It is named after the sport what
happens if you drip the solution which boils at that temperature into cold
water.
Strong sugar solutions are viscous and surprisingly insulative so it's hard to
measure the boiling point accurately - it's very easy to have the base of the
pan much hotter than the boiling point, and it's also easy to measure a cold
pocket of the liquid, or to let it come off the boil. The heat has to be low, the
liquid has to be JUST boiling, it needs to be stirred, and the thermometer
needs to be properly submerged. Then it's very accurate.
The ancients determined the proportions in the solution by dripping the liquid
into cold water and observing its physical properties. Traditional Scottish
grannies can do it incredibly accurately by observing the colour and viscosity
of the liquid. You should buy a sugar thermometer.
Most tablet recipes start with condensed milk to save time and to make it
easier to get to hydrolysis. As condensed milk is just boiled milk and sugar,
and as the recipe already contains milk and sugar and boiling I have reverse
engineered the original recipe that uses fundamental ingredients. If you could
find nice fatty milk you could probably do away with the butter too.
Tablet (from fundamentals)
==========================
20oz sugar
20oz whole milk (1 UK pint, 1.25 US pints) (I think you might call whole milk “3.5%”)
1.5oz butter
Butter a cake tin or baking tray.
In a heavy pan dissolve the sugar and butter in the milk and bring it to the
boil.
Boil without stirring until hydrolysis starts (about 30 mins)
Boil gently and stir constantly to the soft ball stage (about another 30 mins)
Take off the heat and stir constantly until the mixture will only just pour.
Pour and scrape the mixture into the cake tin and press it down. The mixture is
VERY hot, don't burn yourself, don't set the kitchen on fire.
Cut the mixture into chunks in the tin after 15 mins
Cool for at least 2 hours.