I’ve been doing some reading and here’s basically the way maple harvesting and production works: As winter comes in and temperatures drop below freezing, Maple trees will draw in water, which eventually freezes. This water becomes sugary (mostly sucrose), as it is stored in the tree through the winter. When spring finally comes, and temperatures are still fluctuating between freezing at night and above freezing at day, pressure is created within the tree. It’s a narrow time window that this occurs, often as short as one week a year, but If a “wound” is introduced to the tree trunk, the water collected in the winter (now sap) will flow out.

Maple sap is actually fairly watery - only somewhere between 1 and 4% sugar. Maple syrup makers bring the sap into a sugar shack, where it is heated up, evaporating off the water and concentrating the sugar percentage. To make maple syrup, it can take up to 50-60 gallons of sap to produce one gallon of syrup, which is usually 66% sugar. There’s also a maillard reaction which causes the syrup to darken to its trademark amber and brown colors.

Tom is a member of a CSA who also have a connection a maple producer somewhere south of Buffalo. I believe in the woods south of East Aurora. If you’re not familiar - it’s a pretty rustic, sparsely populated area probably 30 miles south of Buffalo proper. These folks are very much off the beaten path, but have a plot with a couple of thousand maple trees. Many of these are plumbed directly into the sugar shack, but there are still some with an old fashioned bucket collection system, which need to be hand-picked up throughout the woods.

One of two 5 gallon containers of ~2.7% maple sap

Tom took a lunchtime trip out on Friday and came away with 10 gallons of freshly harvested maple sap, as well 64 oz of last year’s syrup. The sap is fairly highly concentrated at ~2.7% sugar. Under 2% is much more common. When I say it was fresh, I’m not kidding. It had pieces of bark and leaves in it - completely unfiltered and natural, just what we wanted.

Tom also took the picture of the sugar shack above and had some stories of fresh maple syrup consumption (like pouring hot syrup over fresh cornbread, straight out of the evaporator) that made me pretty jealous. At roughly the same time, I think I was sitting on a conference call and eating a can of soup. He wins this round.

I’ve heard Maple sap compared to milk, in that it will spoil very quickly if not refrigerated or used promptly. Fortunately, we both had the day free yesterday (Saturday 3/30) and got started with the brew around 10 am. It was a sunny day around 45 degrees, which is the best we’ve had in months - a great day to put a fun beer together.

Mash sap, heating up to temperature (~172F)

We decided to make the beer an Imperial Porter, using the fresh maple sap as our brewing liquor. The sap increases the gravity a bit, but does not necessarily add a lot of maple flavor. From what I’ve read, using sap or syrup during the brew/boil will actually impart more of a woody flavor than classic maple sweetness. I want the woody quality, but with that in mind, we’ll also be adding 64 oz (two quarts) of 66% maple syrup to the secondary, which should give a great maple flavor and increase the alcohol percentage.

One of the other considerations that we had to keep in mind, was the unknown quantity of minerals in the sap. I know what’s in my water, and often modify it to meet my grist and/or beer goals. This time around, I relied on pH measurements to ensure that I was going to get decent mash conversion. Using a lot of roasted grains in the mash, I knew I would probably need to increase alkalinity. I wound up adding a few grams each of CaSO4, CaCO3 and MgSO4 to ensure some mineral content. Once I checked the pH, it was actually a little high for the mash, at 5.6, so I used a little (food grade) lactic acid to bring it down to 5.3/4. The sparge sap’s pH was around 6.2, which I determined to be a pretty good level and not requiring adjustment. All in all, this worked out well as our mash efficiency was probably in the 77% range. *This was a little difficult to calculate, as the concentration of the maple sap was also providing a somewhat unknown amount of dissolved sugar.

I kept the recipe fairly simple, as the different maple additions are going to provide plenty of complexity. With simple 2-row base, a heavy hand of Roasted Barley and a variety of flavorful adjuncts, I think we’re well on our way to a really special beer. My yeast of choice was White Labs’ WLP007 Dry English strain, which is quickly becoming my go-to. It’s fast, furious, flocculent, flavorful and has a high alcohol tolerance. The last part will come into play when we bottle condition this in a few weeks.

When it came time to brew, we had 10 gallons of sap to work with - a little more than we needed. I really didn’t want any to go to waste, so we wound up using it all in the mash and sparge, and extending the boil to concentrate down to the gravity and quantity that we wanted. This wound up being a bit more of a commando brew than I usually do, but it was fun and worked out well. The only bad thing is, it makes it more difficult to reproduce. I think in the long run, that’ll be part of the magic behind this one as I open each bottle.

Following primary fermentation, we’ll rack into a clean secondary with the 2 quarts of maple syrup. In an effort to add as much maple ‘terroir’ as possible, I’m also working on sourcing some maple cubes or spirals (wood), which will also be added to the secondary to give a maple-barrel aged essence.

In the end, this will be a big (~10.8% abv), roasty, maple-y beer with a great story behind it. I’m excited to see this one progress and share with friends.

Here’s the recipe:

Sap, Syrup & Wood Imperial Porter Brewed 3/30/13

Size: 6 gal Efficiency: 77% (estimated) Attenuation: 79% (anticipated) Original Gravity: 1.083 (measured. 2 qt of maple syrup should bring to 1.103) Terminal Gravity: 1.019 (estimated)

Color: 29.79 SRM Alcohol: 10.82% IBU: 33

Water: Unknown (maple sap). Added gypsum, epsom salt and chalk to create a baseline

Ingredients:

12 lbs. Canadian 2-row

1.25 lb Roasted Barley

1 lb. Aromatic Malt

0.5 lb Crystal 60L

0.5 lb Belgian Chocolate Malt

0.25 lb Kiln Coffee Malt

0.66 oz Columbus (16.1%) - boiled 90+ minutes

White Labs WLP007 - Dry English. Big pitch from American ESB brew

64 oz pure, 66% maple syrup.  To be pasteurized to 180F, cooled and added to secondary

Notes:

3/30: Brewed on a sunny Saturday afternoon with Tom (we’re splitting the batch). Mark and Alex were here to help/hang out. Winging it a little due to some unknowns, but everything went great and the wort tasted unbelievably good. Drank a bunch of beers, ate some cheese and pizza while brewing. No complaints whatsoever

Mashed at 153F, boiled for around 100 minutes. Cooked down from about 8.75 gal and wound up with around 6 gallons of 1.083 wort (had planned for 1.077). Once I add 2 quarts of 66% maple syrup to the secondary, this might as well be 1.103.

Chilled to 68F, pitched a huge yeast slurry from my last batch and left at an ambient of 58F to kick off.

Fermentation in full roar by morning