I've been planning to brew a beer with spruce tips and did some research to decide how to go about doing it. The gold standard in spruce tip syrup making is half a glass jar of tightly packed fresh spruce tips with the top half of the jar full of white sugar. This goes on a south-facing window and the sun supposedly melts the sugar and as it runs down, it captures the taste and healthiness from the spruce tips better than any other method.
Looked up the melting temperature of pure white sugar: 160 °C. Got a bit doubtful of the aforementioned method (wife has also tried and failed). So my plan would be to pack the tips and sugar on top in a tall kettle and melt the sugar in the oven. Tips go in a mesh insert, so after the sugar has melted, I could pour hot water into the kettle, dissolve the sugar in the water and lift out the mesh insert with the tips.
Today was the time to act it out. Spruce tips from the back yard, 1 kg of sugar. In the oven set at 160 °C, and yes indeed, sugar melts and the aroma from the spruce tips is amazing and appetising!
The beer has 4,75 kg of Viking Sahti malt mix, 1 kg Viking wheat malt, 1 kg Viking Munich Light and 250 g Simpsons Premium English Caramalt in a 19 liter mash. For hops I used Challenger from the start of the boil and some Simcoe for the last 20 minutes. It all came together to make a lovely pale brew.
The spruce component ended up as 2 litres of surprisingly dark green-brown liquid. I made sure all sugar was dissolved and dunked it into the fermenter first, followed by the wort. Both were filtered with reusable coffee filters.
My last doubt was that the spruce tips might contain stuff that would kill the yeast, so I made a starter with some of the spruce-sugar liquid. Sure enough, it got on bubbling like a champ!
Awesome design! I'll drop a few thoughts on it.
Darkening is just sugar caramelization accelerated greatly by acidity of tips. Just a small pH drop in moisture - and tips are tart - accelerates the process by orders of magnitude.
With high temperature, you lose some volatile stuff unless you have it all sealed (which itself is explosive). I think you can achieve similar extraction by alcohol groups (that's what sugar does) by adding tips in secondary. But then you won't have all this caramel. Caramel could come from specialty malt or sugar caramelized separately. Anyway, overdefined problems are just more refined tools for future experiments!
Was this tips extraction simple? And filtration?
Wow, thanks once again for insight! Yes, this method was easy and fast, although what I was hoping for was no caramellisation of the sugar. The windowsill method supposedly produces a clear end result. @[email protected] there solved that part of the puzzle, in fact it's going to just dissolve the sugar with moisture evaporating from the spruce. The ultimate extraction in hindsight would probably have been with sugary water in a sealed vessel in the fridge for a couple of days...? Or honey, as you pointed out. I was hoping to not have too many competing aromas so that the tips would shine through.
Filtering was also easy, very little of the tips escaped the mesh basket. I filtered the tips solution heated up, and the sugar didn't clog the coffee filter at all, and I was able to filter the wort with the same filter bag.
My tall kettle had a lid on, but yeah, some volatiles are gone with the wind. Keenly waiting to sample the end result. However, an extraction method without heating shall be the ultimate goal...
The ultimate extraction would likely be achieved with high proof alcohol. Sugar syrup I think would be less effective than with dry sugar as the dry sugar would exert more osmotic pressure on the tips to draw liquid (and thus flavor) out of the tips.
You can also add them to the boil as you would hops.
Overcooled sugar syrup (what people usually make by heating sugar in water and then cooling down) would technically be a suspension of sugar nanoparticles in saturated syrup. This should totally be more potent for chemical extraction than pure sugar, even after extraction of fluids into it which could only saturate it into syrup phase.
Throwing alcohol into beer preparation souds like illegal move in Finland an USA afaik, LOL