And we're very happy that our Samuel Adams Restaurants Strong Fund has raised over $5.4 million so far to support bar and restaurant workers who are experiencing hardship in the wake of COVID-19.
Working with the Greg Hill Foundation, this fund is committed to distributing 100% of its proceeds to grants to bar and restaurant workers across the country.
While doing this, we also achieved depletions growth of 46% in the second quarter of which 42% is from Boston Beer legacy brands and 4% is from the addition of the Dogfish Head brands.
Given our trends for the first half and our current view of the remainder of the year, we've adjusted our expectations for higher 2020 full-year earnings, depletions and shipment growth, which is primarily driven by the strong performance of our Truly and Twisted Tea brands.
Based on information in hand, year-to-date depletions reported to the company through the 28 weeks ended July 11, 2020, are estimated to have increased approximately 42% from the comparable weeks in 2019.
Excluding the Dogfish Head impact, depletions increased 37%.
For the second quarter, we reported net income of $60.1 million, an increase of $32.3 million or 116% from the second quarter of 2019.
Earnings per diluted share were $4.88, an increase of $2.52 per diluted share from the second quarter of 2019.
This increase was primarily due to increased revenue driven by shipment growth of 39.8% partly offset by lower gross margins and higher operating expenses.
We began seeing the impact of COVID-19 pandemic in our business in early March.
To-date, the direct financial impact of the pandemic has primarily shown in significantly reduced keg demand from the on-premise channel and higher labor and safety related cost at our breweries.
In the first half of 2020, we reported COVID-19 pre-tax-related reductions in net revenue and increases in other costs totally $14.1 million, of which $10 million was recorded in the first quarter and $4.1 million was recorded in the second quarter.
The total amount consists of a $5.8 million reduction in net revenue for our estimated keg returns from distributors and retailers, and $8.3 million of other COVID-19 related direct costs, of which $5.6 million are recorded in cost of goods sold and $2.7 million are recorded in operating expenses.
Shipment volume was approximately 1.9 million barrels, a 39.8% increase from the second quarter of 2019.
Excluding the addition of the Dogfish Head brand beginning July 3, 2019, shipments increased 35.3%.
We believe distributor inventory as of June 27, 2020 averaged approximately 2.5 weeks on hand and was lower than prior year levels due the supply chain capacity constraints.
Our second quarter 2020 gross margin of 46.4% decreased from the 49.9% margin realized in the second quarter of 2019 primarily as a result of higher processing cost due to increased production in third-party breweries, partially offset by price increases and cost-saving initiatives at company-owned breweries.
Second quarter advertising, promotional and selling expenses increased by $6.3 million in the second quarter of 2019 primarily due to increases in salaries and benefits cost, increased brand investments in media and production, the addition of Dogfish Head brand related expenses beginning July 3, 2019, and increased freight to distributors due to higher volumes partially offset by decreased investments in local marketing and national promotions due to timing of these costs compared to the prior year.
General and administrative expenses increased by $2.9 million in the second quarter of 2019, primarily due to increases in salaries and benefits cost and the addition of Dogfish Head general and administrative expenses beginning July 3, 2019, partially offset by the non-recurrence of $1.5 million in Dogfish Head transaction-related fees incurred in the second quarter of 2019.
Based on information which we're currently aware, we are now targeting full year 2020 earnings per diluted share of between $11.70 and $12.70.
This projection excludes the impact of ASU 2016-09.
Full year 2020 depletions growth including Dogfish Head is now estimated to be between 27% and 35% of which between 1% and 2% are due to the addition of the Dogfish Head brand.
We project increases in revenue per barrel of between 1% and 2%.
Full year 2020 gross margins are expected to be between 46% and 48%.
We plan to increase investments in advertising, promotional and selling expenses of between $70 million and $80 million for the full year 2020.
We estimate our full year 2020 non-GAAP effective tax rate to be approximately 26%, which excludes the impact of ASU 2016-09.
We are continuing to evaluate 2020 capital expenditures and currently estimate investments of between $180 million and $200 million.
We expect that our cash balance of $86.7 million as of June 27, 2020 along with our future operating cash flow and unused line of credit of $150 million will be sufficient to fund future cash requirement.

Summary:
Given our trends for the first half and our current view of the remainder of the year, we've adjusted our expectations for higher 2020 full-year earnings, depletions and shipment growth, which is primarily driven by the strong performance of our Truly and Twisted Tea brands.
Earnings per diluted share were $4.88, an increase of $2.52 per diluted share from the second quarter of 2019.
We began seeing the impact of COVID-19 pandemic in our business in early March.
To-date, the direct financial impact of the pandemic has primarily shown in significantly reduced keg demand from the on-premise channel and higher labor and safety related cost at our breweries.
In the first half of 2020, we reported COVID-19 pre-tax-related reductions in net revenue and increases in other costs totally $14.1 million, of which $10 million was recorded in the first quarter and $4.1 million was recorded in the second quarter.
Based on information which we're currently aware, we are now targeting full year 2020 earnings per diluted share of between $11.70 and $12.70.